Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L7/00—Electrodynamic brake systems for vehicles in general
  • B60L7/10—Dynamic electric regenerative braking
  • B60L7/12—Dynamic electric regenerative braking for vehicles propelled by dc motors
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L15/00—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles
  • B60L15/20—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
  • B60L15/2009—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed for braking
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L15/00—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles
  • B60L15/20—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
  • B60L15/2036—Electric differentials, e.g. for supporting steering vehicles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L50/00—Electric propulsion with power supplied within the vehicle
  • B60L50/50—Electric propulsion with power supplied within the vehicle using propulsion power supplied by batteries or fuel cells
  • B60L50/52—Electric propulsion with power supplied within the vehicle using propulsion power supplied by batteries or fuel cells characterised by DC-motors
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L2200/00—Type of vehicles
  • B60L2200/18—Buses
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L2200/00—Type of vehicles
  • B60L2200/26—Rail vehicles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L2220/00—Electrical machine types; Structures or applications thereof
  • B60L2220/40—Electrical machine applications
  • B60L2220/44—Wheel Hub motors, i.e. integrated in the wheel hub
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L2240/00—Control parameters of input or output; Target parameters
  • B60L2240/10—Vehicle control parameters
  • B60L2240/12—Speed
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L2240/00—Control parameters of input or output; Target parameters
  • B60L2240/10—Vehicle control parameters
  • B60L2240/24—Steering angle
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L2240/00—Control parameters of input or output; Target parameters
  • B60L2240/40—Drive Train control parameters
  • B60L2240/42—Drive Train control parameters related to electric machines
  • B60L2240/421—Speed
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L2240/00—Control parameters of input or output; Target parameters
  • B60L2240/40—Drive Train control parameters
  • B60L2240/42—Drive Train control parameters related to electric machines
  • B60L2240/423—Torque
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L2240/00—Control parameters of input or output; Target parameters
  • B60L2240/40—Drive Train control parameters
  • B60L2240/48—Drive Train control parameters related to transmissions
  • B60L2240/486—Operating parameters
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L2250/00—Driver interactions
  • B60L2250/10—Driver interactions by alarm
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L2250/00—Driver interactions
  • B60L2250/16—Driver interactions by display
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L2250/00—Driver interactions
  • B60L2250/26—Driver interactions by pedal actuation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L2270/00—Problem solutions or means not otherwise provided for
  • B60L2270/20—Inrush current reduction, i.e. avoiding high currents when connecting the battery
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/60—Other road transportation technologies with climate change mitigation effect
  • Y02T10/64—Electric machine technologies in electromobility
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/60—Other road transportation technologies with climate change mitigation effect
  • Y02T10/70—Energy storage systems for electromobility, e.g. batteries
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/60—Other road transportation technologies with climate change mitigation effect
  • Y02T10/72—Electric energy management in electromobility

Definitions

• the present disclosure generally relates to an electric vehicle, and more particularly to a driving system of an electric vehicle and a method for controlling the same.
• Embodiments of the present disclosure seek to solve at least one of the problems existing in the prior art to at least some extent.
• a driving system of an electric vehicle comprises: a power battery; a plurality of first in- wheel motors connected with the power battery; a plurality of first motor controllers configured to control the plurality of first in-wheel motors respectively; a plurality of second in-wheel motors connected with the power battery; a plurality of second motor controllers configured to control the plurality of second in-wheel motors respectively; and a vehicle management system controller connected with the plurality of first motor controllers and the plurality of second motor controllers respectively, and configured to control the plurality of first in-wheel motors and the plurality of second in-wheel motors to start or stop via the plurality of first motor controllers and the plurality of second motor controllers during a running of the electric vehicle.
• the driving system of the electric vehicle may have advantages of the electric vehicle and the four-wheel driving system.
• torques acting on a left wheel and a right wheel may be adjusted in time via an independent control of a left in-wheel motor and a right in-wheel motor, which may increase a driving efficiency, improve a transverse oscillation, more effectively apply a pulling force and a steering force to a wheel, and obtain a relatively high stability and driving safety.
• the driving system of the electric vehicle is easy to operate, low in cost and easy to industrialize.
• a method for controlling a driving system of an electric vehicle comprises: judging whether the electric vehicle has started; if yes, sending a driving control signal to a plurality of first motor controllers and a plurality of second motor controllers; and controlling a plurality of first in-wheel motors and a plurality of second in-wheel motors to start or stop via the plurality of first motor controllers and the plurality of second motor controllers, when the plurality of first motor controllers and the plurality of second motor controllers receive the driving control signal.
• the driving system of the electric vehicle may have advantages of the electric vehicle and the four-wheel driving system.
• torques acting on a left wheel and a right wheel may be adjusted in time via an independent control of a left in-wheel motor and a right in-wheel motor, which may increase a driving efficiency, improve a lateral ride condition, more effectively apply a pulling force and a steering force to a wheel, and obtain a relatively high stability and driving safety.
• the method is easy to operate, low in cost and easy to be industrialized.
• Fig. 1 is a working condition graph of an urban public transport
• Fig. 2 is a simulation graph of a power of a whole vehicle
• Fig. 3 is a climbing power graph of the whole vehicle
• Fig. 4 is a block diagram of a driving system of an electric vehicle according to an embodiment of the present disclosure
• Fig. 5 is a block diagram of a connection relationship of elements of the driving system of the electric vehicle according to an embodiment of the present disclosure
• Fig. 6 is a schematic diagram of a power transmission of the electric vehicle according to an embodiment of the present disclosure
• Fig. 7 is a logic flow chart showing a method for controlling the driving system of the electric vehicle according to an embodiment of the present disclosure
• Fig. 8 is a power graph of the electric vehicle under a normal working condition
• Fig. 9 is a logic flow chart showing a method for controlling the driving system of the electric vehicle to switch between a two-wheel drive and a four-wheel drive;
• Fig. 10 is a principle diagram showing driving the electric vehicle by the two-wheel drive
• Fig. 11 is a principle diagram of a braking regeneration of the electric vehicle driven by the two-wheel drive
• Fig. 12 is a principle diagram showing driving the electric vehicle by the four-wheel drive
• Fig. 13 is a schematic diagram of a model of a four-wheel electric vehicle
• Fig. 14 is a flow chart of a method for controlling a speed differential of the electric vehicle
• Fig. 15 is a flow chart of a method for controlling a driving system of an electric vehicle according to an embodiment of the present disclosure
• Fig. 16 is a flow chart of a method for controlling a driving system of an electric vehicle according to another embodiment of the present disclosure
• Fig. 17 is a graph of a vehicle speed versus a throttle depth.
• a structure in which a first feature is "on" a second feature may include an embodiment in which the first feature directly contacts the second feature, and may also include an embodiment in which an additional feature is formed between the first feature and the second feature so that the first feature does not directly contact the second feature.
• the terms “mounted,” “connected,” and “coupled” and variations thereof are used broadly and encompass such as mechanical or electrical mountings, connections and couplings, also can be inner mountings, connections and couplings of two components, and further can be direct and indirect mountings, connections, and couplings, which can be understood by those skilled in the art according to the detail embodiment of the present disclosure.
• Fig. 1 is a working condition graph of an urban public transport.
• Fig. 2 is a simulation graph of the power of the whole vehicle. For the all electric vehicle with an in-wheel driving mode, a maximum driving power can reach 180Kw, which can satisfy the power requirement of a normal vehicle.
• Fig. 3 is a climbing power graph of the whole vehicle.
• the maximum power reaches 237Kw which may satisfy a running requirement of the whole vehicle, and if two motors work simultaneously, the maximum vehicle speed is greater than 77.6 Km/h, the gradeability is greater than 13.9%, and the accelerating time from 0 second to 50 seconds is required to be less than 20.6 seconds. It can be seen from above results that the gradeability of the double-layered all electric vehicle cannot satisfy the requirement of the working condition of the public transport.
• Fig. 4 is a block diagram of the driving system of the electric vehicle according to embodiments of the present disclosure.
• the driving system of the electric vehicle comprises a power battery 100, a plurality of first in-wheel motors 200, a plurality of first motor controllers 300, a plurality of second in-wheel motors 400, a plurality of second motor controllers 500, a vehicle management system controller 600 and a battery management device 700.
• the plurality of first in-wheel motors 200 are connected with the power battery 100 and the plurality of first motor controllers 300 control the plurality of first in-wheel motors 200 respectively.
• the plurality of second in-wheel motors 400 are connected with the power battery 100 and the plurality of second motor controllers 500 control the plurality of second in-wheel motors 400 respectively.
• the vehicle management system controller 600 is connected with the plurality of first motor controllers 300 and the plurality of second motor controllers 500 respectively, and the vehicle management system controller 600 controls the plurality of first in-wheel motors 200 and the plurality of second in-wheel motors 400 to start or stop via the plurality of first motor controllers 300 and the plurality of second motor controllers 500 during a running of the electric vehicle.
• the vehicle management system controller 600 controls the plurality of first motor controllers 300 and the plurality of second motor controllers 500 to start simultaneously, or controls to switch the plurality of first motor controllers 300 and the plurality of second motor controllers 500, i.e. to start either the plurality of first motor controllers 300 or the plurality of second motor controllers 500.
• the vehicle management system controller 600 is further configured to control the plurality of first in-wheel motors 200 and the plurality of second in-wheel motors 400 to start via the plurality of first motor controllers 300 and the plurality of second motor controllers 500 during the start of the electric vehicle.
• the vehicle management system controller 600 is yet configured to control the plurality of second in-wheel motors 400 to stop via the plurality of second motor controllers 500, when the speed change rate of the electric vehicle is less than a first preset value.
• vehicle management system controller 600 A specific function of the vehicle management system controller 600 will be described in detail with reference to embodiments of the present disclosure.
• the driving system of the electric vehicle refers to a vehicle management strategy, an in-wheel power system and a vehicle management system controller 600.
• the vehicle management strategy describes a process flow of the vehicle management.
• the in-wheel power system mainly includes the plurality of first in-wheel motors 200, the plurality of first motor controllers 300, the plurality of second in-wheel motors 400 and the plurality of second motor controllers 500.
• the vehicle management system controller 600 is mainly in charge of a distribution of the power of the electric vehicle. By combining the management strategy, the vehicle management system controller 600 and the in-wheel power system, the electric vehicle may be operated according to a driver's wishes without any other outer modification.
• a connection relationship of elements of the driving system of the electric vehicle is shown in Fig. 5.
• first motor controllers e.g., 310 and 320
• second motor controllers e.g., 510 and 520
• numbers of the first motor controllers and the second motor controllers may be determined according to practice.
• the vehicle management system controller 600 may be applied in a vehicle with a length less than 30m, including a two-wheel drive vehicle, a four-wheel drive vehicle, a six-wheel drive vehicle, and so on, which may reduce a development cost and shorten a research cycle.
• a load of a CAN net is reduced, the transmission efficiency is improved and a bus data error is decreased.
• a driving efficiency is improved, and the in-wheel systems may be effectively balanced and coordinated.
• the plurality of first in-wheel motors 200 and the plurality of second in-wheel motors 400 are configured to output current under a control of the plurality of first motor controllers 300 and the plurality of second motor controllers 500 so as to control an output of a torque, thus controlling the electric vehicle to move forward, backward and the like.
• the vehicle management system controller 600 is configured to: (1) communicate with the electric vehicle including receiving a state information of the electric vehicle; (2) receive, synthesize and send information from the two first motor controllers (e.g., 310 and 320) and the two second motor controllers (e.g., 510 and 520); (3) distribute the power of the electric vehicle, including simultaneously receiving data from the two first motor controllers (e.g., 310 and 320) and the two second motor controllers (e.g., 510 and 520), calculating a target power requirement of the electric vehicle, and sending a driving command to the two first motor controllers (e.g., 310 and 320) and the two second motor controllers (e.g., 510 and 520); (4) control an alternating current charging system; (5) collect a steering angle signal of a steering wheel for calculating a driving force of each in-wheel driver.
• the two first motor controllers e.g., 310 and 320
• the two second motor controllers e.g., 510 and
• the vehicle management system controller 600 comprises two CAN nets, one CAN net communicates with the electric vehicle, and the other CAN net, the two first motor controllers (e.g., 310 and 320) and the two second motor controllers (e.g., 510 and 520) form a power subnet.
• the two first motor controllers e.g., 310 and 320
• the two second motor controllers e.g., 510 and 520
• the first motor controllers 300 and the second motor controllers 500 are configured to receive the driving command from the vehicle management system controller 600, to drive the electric vehicle according to the target power requirement from the vehicle management system controller 600, and to collect actual driving data or actual braking regeneration data and send them to the vehicle management system controller 600.
• the driving system of the electric vehicle will be described based on a four-wheel-driving vehicle management system controller, and associated with a comparison between the four-wheel-driving vehicle management system controller and a two-wheel-driving vehicle management system controller.
• Fig. 6 is a schematic diagram of a power transmission of the electric vehicle according to an embodiment of the present disclosure.
• the four-wheel-driving vehicle management system controller 600 is a low-voltage controller configured to distribute the power of the electric vehicle.
• the vehicle management system controller 600 calculates the power requirement via receiving an accelerator pedal signal, a braking pedal signal, a gear signal, the steering angle signal of the steering wheel, an electric quantity of the power battery 100 and so on, and distributes powers and torques to the first motor controllers 300 and the second motor controllers 500.
• the first motor controllers 300 and the second motor controllers 500 receive the torque signal and the power signal and drive corresponding in- wheel motors thereof according to the received signals.
• the electric vehicle comprises an accelerator pedal signal sensor mounted on an accelerator pedal of the electric vehicle, and mainly configured to sample a trampling depth of the accelerator pedal.
• the electric vehicle comprises a braking pedal signal sensor mounted on a braking pedal of the electric vehicle, and mainly configured to sample a trampling depth of the braking pedal.
• the gear signal represents a gear in which the electric vehicle is, and the gear has three states of N, R, D.
• the electric vehicle comprises a steering angle signal sensor of the steering wheel mounted on a steering column of the electric vehicle, and mainly configured to collect the steering angle signal of the steering wheel.
• the vehicle management system controller 600 is configured to receive the electric quantity information of the power battery 100 from the battery management device 700.
• the second in- wheel motor 400 drives an input shaft gear 410 to drive intermediate shaft deceleration gears 480 and 490
• a deceleration output gear 420 drives an output shaft 430
• the output shaft 430 drives a sun gear 440 in a planetary gear reduction mechanism
• a gear ring 470 in a planetary-gear hub drive is fixed
• a planetary gear 450 drives a planetary carrier 460
• the planetary carrier 460 is connected with the wheels via a hub flange.
• the power of the second in-wheel motor 400 is transmitted to the wheels to drive the vehicle.
• the battery management device 700 is configured to sample a temperature, a voltage and a current output by the power battery 100, to calculate a residual electric quantity of the power battery 100, and to send a control signal to related electric components via a CAN communication line.
• the first motor controllers 300 and the second motor controllers 500 which are high- voltage devices are configured to control the power of the motor, that is, the first motor controllers 300 and the second motor controllers 500 are configured to transform a direct current supplied by the power battery 100 to a three-phase alternating current which is required by the first in-wheel motors 200 and the second in-wheel motors 400 via an internal driving circuit thereof, and to control the first in-wheel motors 200 and the second in-wheel motors 400 to run under a limited power according to a signal sent by the battery management device 700.
• the driving system of the electric vehicle further comprises a high-voltage electric distribution box, configured to distribute a high voltage output by the power battery 100, and comprising a relay, a primary contactor and a pre-charging contactor.
• the battery management device 700 controls the primary contactor and the pre-charging contactor to switch on or off so as to realize the high voltage distribution.
• the power battery 100 is configured to supply electric energy and comprises a plurality of batteries connected in series.
• Fig. 7 is a logic flow chart showing a method for controlling the driving system of the electric vehicle according to an embodiment of the present disclosure.
• the management system strategy of the electric vehicle will be described below based on the functions of the battery management device 700, the plurality of first motor controllers 300 and the plurality of second motor controllers 500.
• the battery management device 700 connected with the power battery 100, the electric high- voltage distribution box and the vehicle management system controller 600 respectively, is configured to control the primary contactor to switch off and the pre-charging contactor to switch on so as to pre-charge the plurality of first motor controllers 300 and the plurality of second motor controllers 500 via the power battery 100 after the electric vehicle is powered on, and configured to detect an electric quantity of the power battery 100 in real time, if the electric quantity of the power battery 100 is sufficient, to control the plurality of first in- wheel motors 200 and the plurality of second in-wheel motors 400 to output power according to a calculated power, and if the electric quantity of the power battery 100 is insufficient, to control the plurality of first in-wheel motors 200 and the plurality of second in-wheel motors 400 to output power according a preset maximum power.
• the plurality of first motor controllers 300 and the plurality of second motor controllers 500 are further configured to detect a bus voltage, and to feed back the bus voltage to the battery management device 700 via the vehicle management system controller 600.
• the battery management device 700 is further configured to judge whether the plurality of first motor controllers 300 and the plurality of second motor controllers 500 have been pre-charged according to the bus voltage, and if yes, to control the primary contactor to switch on and the pre-charging contactor to switch off.
• a controlling logic of the electric vehicle comprises following steps.
• step S701 the electric vehicle is powered on, the braking pedal is trampled and a driving button is pressed.
• the battery management device 700 controls a negative electrode contactor and the pre-charging contactor in a primary circuit to switch on, and sends a pre-charging state message, and the power battery 100 pre-charges the first motor controllers 300 and the second motor controllers 500.
• the first motor controllers 300 and the second motor controllers 500 sample and send real-time bus voltage to the vehicle management system controller 600.
• the vehicle management system controller 600 receives the real-time bus voltage and sends four maximal values of the real-time bus voltage to the battery management device 700.
• step S705 the battery management device 700 judges whether the bus voltage is larger than 370V. If yes, step S706 is followed; if no, step S705 is followed.
• the pre-charging is considered to be finished, the primary contactor is switched on, the pre-charge contactor is switched off, and a pre-charging finish message is sent out.
• a pre-charging finish message is sent out after the vehicle management system controller 600 receives the pre-charging finish message, an "OK" message is sent to an instrument via a gateway, and the instrument displays the "OK” message and turns on an OK light. At this time, a charging is finished, and the electric vehicle is in a discharging mode.
• step S708 the vehicle management system controller 600 judges whether the gear signal is
• step S717 is followed; if yes, step S709 is followed.
• step S709 it is judged whether a hand-brake is released. If no, step S717 is followed; if yes, step S710 is followed.
• step S710 it is judged whether there is the braking signal. If no, step 717 is followed; if yes, step S711 is followed.
• step S711 it is judged whether the throttle depth signal is received. If no, step 717 is followed; if yes, step S712 is followed.
• the vehicle management system controller 600 searches a target speed, and calculates a required power and a required torque T8 of the electric vehicle.
• the vehicle management system controller 600 calculates the steering angle R of the steering wheel.
• the vehicle management system controller 600 distributes the required torque and the required powers PI and P2 to each first motor controller 300 and the required torque and the required powers P3 and P4 to each second motor controller 500.
• each first motor controller 300 and each second motor controller 500 work with the required torque and required powers.
• step S716 it is judged whether there is a stop signal or an error signal. If no, step S711 is followed; if yes, step S717 is followed.
• step S717 the driving is not allowed.
• the battery management device 700 detects a state of the power battery 100, and sends a message to the vehicle management system controller 600 to allow the electric vehicle to discharge.
• a front assistant controller samples a trampling depth of the accelerator pedal, a trampling depth of the braking pedal and the gear signal and sends them to the vehicle management system controller 600.
• the vehicle management system controller 600 receives the steering angle signal a of the steering wheel, calculates the target speeds ⁇ ⁇ , v 2 , v 3 , v 4 of the four drive wheels, and converts the target speeds into motor rotation speeds Ni, N 2 , N 3 , N 4 .
• the vehicle management system controller 600 obtains an intention of the driver by converting the throttle depth signal into a coefficient C, searches the target speed V and a maximal resistance T5 corresponding to the target speed V. Since the target speed V is corresponding to a motor rotation speed N, the vehicle management system controller 600 searches a power T6 of the motor under the motor rotation speed N, and then a total target torque is calculated by:
• a target torque of each motor is calculated by:
• a power of each motor is calculated by:
• a power of each motor is calculated by:
• Each controller receives a corresponding target torque and a corresponding power, drives a corresponding motor according to the received signals, and simultaneously samples the actual power and torque and sends them to the vehicle management system controller 600.
• the vehicle management system controller 600 After receiving the data from the two first motor controllers 300 and the two second motor controllers 500, the vehicle management system controller 600 performs a new torque distribution based on the electric vehicle information and the actual power and torque to obtain a result, and sends the result to the two first motor controllers 300 and the two motor controllers 500 to perform.
• Any fault or alarm occurring during the whole driving is processed or sent out by the vehicle management system controller 600.
• the vehicle management system controller controls the vehicle management system controller
• the vehicle management system controller 600 is further configured to control the driving system to be switched between the two-wheel drive and the four-wheel drive.
• the vehicle management system controller 600 is also configured to obtain the target speed, and to start the plurality of second in-wheel motors 400 via the plurality of second motor controllers 500, when a difference between the target speed and a current speed is greater than a second preset value.
• Fig. 8 is a power graph of the electric vehicle under a normal working condition.
• the power requirement is about 130Kw
• a set of first in-wheel motors 200 may satisfy the electric vehicle power requirement.
• the two first in-wheel motors 200 and the two second in-wheel motors 400 works simultaneously to drive the electric vehicle.
• Fig. 12 is a principle view showing driving the electric vehicle by the four-wheel drive. Referring to Fig. 12, the first in-wheel motors 200 work as a primary in-wheel driving system, and the second in-wheel motors 400 work as an assistant in-wheel driving system.
• Fig. 11 is a principle view of the braking regeneration of the electric vehicle driven by the two-wheel drive. Referring to Fig. 11, if the throttle pedal is released during the running, the braking regeneration will result in a reduction of the speed. Fig.
• FIG. 10 is a principle view showing driving the electric vehicle by the two-wheel drive.
• the throttle pedal is trampled down, if a target speed v 2 satisfies v 2 -v > A , the assistant in-wheel driving system will be in service and the four-wheel drive mode is used, and if the target speed v 2 satisfies v 2 - v ⁇ A , only the primary in-wheel driving system will be in service and the four-wheel drive mode will not be used.
• the assistant driving system may start as few as possible provided that the actual running requirement is satisfied; in another aspect, when the driving system of the electric vehicle is switched between the two-wheel drive and the four-wheel drive, the total target torque will not be changed, which may ensure a smoothness for the power and a comfort for the passenger.
• Fig. 9 is a logic flow chart showing a method for controlling the driving system of the electric vehicle to switch between the two-wheel drive and the four-wheel drive. Specifically, the method comprises following steps.
• step S901 after the charging of the electric vehicle is finished, the electric vehicle gets ready to run.
• step S902 the throttle pedal is trampled down, and the vehicle management system controller 600 judges whether the throttle depth signal is received. If no, the judging is continued. If yes, step S903 is followed.
• step S903 it is judged whether the difference between the target speed and the current speed is larger than A. If yes, step S904 is executed. If no, step S906 is executed.
• step S904 the power requirement of the electric vehicle is calculated, and the power is distributed to the two first motor controllers 300 and the two second motor controllers 500.
• each motor controller receives the power signal and drives a corresponding in-wheel motor according to the power signal.
• step S906 when the target speed V is reached, the second in-wheel motors 400 stop.
• step S907 the electric vehicle runs at a constant speed.
• step S908 the throttle pedal is released or the braking pedal is trampled down.
• step S909 an energy is regenerated by a drive of the primary in-wheel driving system.
• step S910 the speed is reduced or the electric vehicle stops, and step S902 is followed.
• the two motors when the trampling depth of the accelerator pedal reaches 70%, the two motors output maximal torques. When the trampling depth of the accelerator pedal is beyond 70%, the total torque of the electric vehicle are also outputted directly proportional to the trampling depth of the accelerator pedal, and the four motors output torque in the same state to supply power to the electric vehicle.
• the total torque when the trampling depth of the accelerator pedal reaches 70%, the total torque is 1000N ⁇ M, and the torque output of a single motor is 500N ⁇ M; and when the throttle opening rate is 72%, the total torque may be 1200N ⁇ M, and the torque output of the single motor is 300N ⁇ M.
• the two motors when the trampling depth of the accelerator pedal reaches back to 50%, the two motors output maximal torques.
• the opening rate of the throttle is beyond 70%, the total torque of the electric vehicle is directly proportional to the opening rate of the throttle, and the four motors output torque in the same state to supply power to the electric vehicle.
• the opening rate of the throttle is 50%
• the total torque is 800N ⁇ M
• the torque output of the single motor is 400N ⁇ M.
• the vehicle management system controller 600 is further configured to calculate speeds of an inner wheel and an outer wheel according to a rotation angle of the electric vehicle, and to control one or more first in-wheel motors 200 and one or more second in-wheel motors 400 corresponding to the inner wheel and one or more first in-wheel motors 200 and one or more second in-wheel motors 400 corresponding to the outer wheel respectively according to the speeds of the inner wheel and the outer wheel.
• a left driving wheel and a right driving wheel are required to rotate with different rotation speeds, which is realized by a mechanical differential.
• An inner friction torque of the mechanical differential is so small that torques of a left-half axis and a right-half axis may be approximately regarded as equal. Therefore, a same solution may be used in the driving system of the electric vehicle according to embodiments of the present disclosure, that is, the four motors are given a same torque, while an inner wheel and an outer wheel are provided with different rotation speeds to realize a speed differential.
• Fig. 13 is a schematic diagram of a model of a four-wheel electric vehicle. As shown in Fig. 13, ⁇ is an angle between a line from an instant center at a turning axis to the inner wheel and a middle axis of a primary in-wheel drive axle and an assistant in-wheel drive axle, and ⁇ is an angle between the turning axis and a line from the instant center at the turning axis to the outer wheel. For a same model of electric vehicle, the two angles are known.
• L 3 is an axis distance of the inner and outer wheels
• Li is an axis distance from the middle axis of the primary in-wheel drive axle and the assistant in-wheel drive axle to a front wheel
• ⁇ o is an angular speed when the electric vehicle turns
• v x , v 2 , v 3 , v 4 are rotation speeds of the four driving wheels respectively.
• the target speed of the inner wheel and the target speed of the outer wheel are calculated by following formulas:
• Fig. 14 is a flow chart of a method for controlling the speed differential of the electric vehicle. The method comprises following steps.
• step SI 401 the electric vehicle runs normally.
• step S1402 it is judged whether the electric vehicle is ready to turn. If no, the judging is continued. If yes, step SI 403 is followed.
• a rotation angle and a rotation direction are calculated.
• step S1404 a linear distance from the instant center to the electric vehicle is calculated.
• step SI 405 the rotation speeds of the inner wheel and the outer wheel are calculated.
• step S1406 the target rotation speed of each motor is calculated.
• the target speed and the torque are calculated via the trampling depth of the throttle pedal.
• step S1408 the power requirement of each motor is calculated according to the target speed and the torque.
• the braking regeneration will be described in detail as follows.
• a maximal regeneration power is about 170Kw by analog simulation.
• a braking energy is regenerated mainly using the primary in-wheel driving system, while the assistant in-wheel driving system does not work. If the braking energy regeneration is performed in the four-wheel driving model, a similar solution will be adopted, that is, the primary in-wheel driving system starts while the assistant in-wheel driving system stops.
• the driving system of the electric vehicle may have advantages of the electric vehicle and the four-wheel driving system.
• torques acting on a left wheel and a right wheel may be adjusted in time via an independent control of a left in-wheel motor and a right in-wheel motor, which may increase a driving efficiency, improve a transverse oscillation, more effectively apply a pulling force and a steering force to a wheel, and obtain a relatively high stability and driving safety.
• the driving system of the electric vehicle is easy to operate, low in cost and easy to industrialize.
• Fig. 15 is a flow chart of a method for controlling a driving system of an electric vehicle according to an embodiment of the present disclosure. As shown in Fig. 15, the method comprises following steps.
• step 1501 it is judged whether the electric vehicle has started.
• a driving control signal is sent to a plurality of first motor controllers and a plurality of second motor controllers.
• a plurality of first in-wheel motors and a plurality of second in-wheel motors are controlled to start or stop via the plurality of first motor controllers and the plurality of second motor controllers, when the plurality of first motor controllers and the plurality of second motor controllers receive the driving control signal.
• Fig. 16 is a flow chart of a method for controlling a driving system of an electric vehicle according to another embodiment of the present disclosure. As shown in Fig. 16, the method comprises following steps.
• step S 101 it is judged whether the electric vehicle has started.
• the driving system of the electric vehicle comprises a power battery, a plurality of first in-wheel motors connected with the power battery, a plurality of first motor controllers configured to control the plurality of first in-wheel motors respectively, a plurality of second in-wheel motors connected with the power battery, a plurality of second motor controllers configured to control the plurality of second in-wheel motors respectively, and a vehicle management system controller configured to control the plurality of first in-wheel motors and the plurality of second in-wheel motors to start or stop.
• the vehicle management system controller is further configured to judge whether the electric vehicle has started.
• the driving system of the electric vehicle refers to a vehicle management strategy, an in-wheel power system and a vehicle management system controller.
• the vehicle management strategy describes a process flow of the vehicle management.
• the in-wheel power system mainly includes the plurality of first in-wheel motors, the plurality of first motor controllers, the plurality of second in-wheel motors and the plurality of second motor controllers.
• the vehicle management system controller is mainly in charge of a distribution of the power of the electric vehicle.
• the vehicle management system controller may be applied in a vehicle with a length less than 30m, including a two-wheel drive vehicle, a four-wheel drive vehicle, a six-wheel drive vehicle, and so on, which may reduce a development cost and shorten a research cycle.
• a load of a CAN net is reduced, the transmission efficiency is improved and a bus data error is decreased.
• a driving efficiency is improved, and the in-wheel systems may be effectively balanced and coordinated.
• the vehicle management system controller is configured to: (1) communicate with the electric vehicle including receiving a state information of the electric vehicle; (2) receive, synthesize and send information from the two first motor controllers and the two motor controllers; (3) distribute the power of the electric vehicle, including simultaneously receiving data from the two first motor controllers and the two second motor controllers, calculating a target power requirement of the electric vehicle, and sending a driving command to the two first motor controllers and the two second motor controllers; (4) control an alternating current charging system; (5) collect a steering angle signal of a steering wheel for calculating a driving force of each in-wheel driver.
• the vehicle management system controller comprises two CAN nets, one CAN net communicates with the electric vehicle, and the other CAN net, the two first motor controllers and the two second motor controllers form a power subnet.
• the vehicle management system controller sends a driving control signal to the plurality of first motor controllers and the plurality of second motor controllers.
• the plurality of first in-wheel motors and the plurality of second in-wheel motors are configured to output current under a control of the plurality of first motor controllers and the plurality of second motor controllers so as to control an output of a torque, thus controlling the electric vehicle to move forward, backward and the like.
• the first motor controllers and the second motor controllers are configured to receive the driving command from the vehicle management system controller, to drive the electric vehicle according to the target power requirement from the vehicle management system controller, and to collect actual driving data or actual braking regeneration data and send them to the vehicle management system controller.
• the plurality of first motor controllers and the plurality of second motor controllers control the plurality of first in-wheel motors and the plurality of second in-wheel motors to start or stop when receiving the driving control signal.
• the vehicle management system controller controls the plurality of first in-wheel motors and the plurality of second in-wheel motors to start via the plurality of first motor controllers and the plurality of the second motor controllers.
• Fig. 6 is a schematic diagram of a power transmission of the electric vehicle according to an embodiment of the present disclosure.
• the four-wheel-driving vehicle management system controller 600 is a low-voltage controller configured to distribute the power of the electric vehicle.
• the vehicle management system controller 600 calculates the power requirement via receiving an accelerator pedal signal, a braking pedal signal, a gear signal, the steering angle signal of the steering wheel, an electric quantity of the power battery 100 and so on, and distributes powers and torques to the first motor controllers 300 and the second motor controllers 500.
• the first motor controllers 300 and the second motor controllers 500 receive the torque signal and the power signal and drive corresponding in-wheel motors thereof according to the received signals.
• the electric vehicle comprises an accelerator pedal signal sensor mounted on an accelerator pedal of the electric vehicle, and mainly configured to sample a trampling depth of the accelerator pedal.
• the electric vehicle comprises a braking pedal signal sensor mounted on a braking pedal of the electric vehicle, and mainly configured to sample a trampling depth of the braking pedal.
• the gear signal represents a gear in which the electric vehicle is, and the gear has three states of N, R, D.
• the electric vehicle comprises a steering angle signal sensor of the steering wheel mounted on a steering column of the electric vehicle, and mainly configured to collect the steering angle signal of the steering wheel.
• the vehicle management system controller 600 is configured to receive the electric quantity information of the power battery 100 from the battery management device 700.
• the second in- wheel motor 400 drives an input shaft gear 410 to drive intermediate shaft deceleration gears 480 and 490
• a deceleration output gear 420 drives an output shaft 430
• the output shaft 430 drives a sun gear 440 in a planetary gear reduction mechanism
• a gear ring 470 in a planetary-gear hub drive is fixed
• a planetary gear 450 drives a planetary carrier 460
• the planetary carrier 460 is connected with the wheels via a hub flange.
• the power of the second in-wheel motor 400 is transmitted to the wheels to drive the vehicle.
• Step SI 04 the vehicle management system controller controls the plurality of second in-wheel motors to stop via the plurality of second motor controllers, when a speed change rate of the electric vehicle is less than a first preset value.
• the vehicle management system controller controls the plurality of second in-wheel motors to stop via the plurality of second motor controllers, after the speed of the electric vehicle tends to be stable.
• the first motor controllers and the second motor controllers which are high-voltage devices are configured to control the power of the motor, that is, the first motor controllers and the second motor controllers are configured to transform a direct current supplied by the power battery to a three-phase alternating current which is required by the first in-wheel motors and the second in-wheel motors via an internal driving circuit thereof, and to control the first in-wheel motors and the second in-wheel motors to run under a limited power according to a signal sent by the battery management device.
• the battery management device controls a primary contactor to switch off and a pre-charging contactor to switch on so as to pre-charge the plurality of first motor controllers and the plurality of second motor controllers via a power battery after the electric vehicle is powered on, and detects an electric quantity of the power battery in real time, if the electric quantity of the power battery is sufficient, the battery management device controls the plurality of first in-wheel motors and the plurality of second in-wheel motors to output power according to a calculated power, and if the electric quantity of the power battery is insufficient, the battery management device controls the plurality of first in-wheel motors and the plurality of second in-wheel motors to output power according a preset maximum power.
• the vehicle is powered on, the braking pedal is trampled down and the driving button is pressed, the battery management device controls a negative electrode contactor and the pre-charging contactor in a primary circuit to be switched on, and the power battery pre-charges the first motor controllers and the second motor controllers.
• the plurality of first motor controllers and the plurality of second motor controllers detect a bus voltage, and feed back the bus voltage to the battery management device via the vehicle management system controller.
• the first motor controllers and the second motor controllers sample and send the real-time bus voltage to the vehicle management system controller, and after receiving the real-time bus voltage, the vehicle management system controller sends four maximal values to the battery management device.
• the battery management device judges whether the plurality of first motor controllers and the plurality of second motor controllers have been pre-charged according to the bus voltage, and if yes, controls the primary contactor to switch on and the pre-charging contactor to switch off.
• the battery management device judges whether the bus voltage is larger than 370V. If yes, the pre-charging is considered to be finished, then the primary contactor is switched on, the pre-charge contactor is switched off, and a pre-charging finished message is sent out. After the vehicle management system controller receives the pre-charging finish message, an "OK" message is sent to an instrument via a gateway, and the instrument displays the "OK” message and turns on an OK light. At this time, a charging is finished, and the electric vehicle is in a discharging mode.
• the vehicle management system controller obtains a target speed, and when a difference between the target speed and a current speed is larger than a second preset value, the vehicle management system controller controls the plurality of second in-wheel motors to start via the plurality of second motor controllers.
• Fig. 8 is a power graph of the electric vehicle under a normal working condition.
• the power requirement is about 130Kw
• a set of first in-wheel motors may satisfy the electric vehicle power requirement.
• the two first in-wheel motors 200 and the two second in-wheel motors 400 works simultaneously to drive the electric vehicle.
• Fig. 12 is a principle view showing driving the electric vehicle by the four-wheel drive. Referring to Fig. 12, the first in-wheel motors 200 work as a primary in-wheel driving system, and the second in-wheel motors 400 work as an assistant in-wheel driving system.
• Fig. 11 is a principle view of the braking regeneration of the electric vehicle driven by the two-wheel drive. Referring to Fig. 11, if the throttle pedal is released during the running, the braking regeneration results in a reduction of the speed. Fig.
• FIG. 10 is a principle view showing driving the electric vehicle by the two-wheel drive.
• the throttle pedal is trampled down, if a target speed v 2 satisfies v 2 - v > A , the assistant in-wheel driving system is in service and the four-wheel drive mode is used, and if the target speed v 2 satisfies v 2 - v ⁇ A , only the primary in-wheel driving system is in service and the four-wheel drive mode is not used.
• the assistant driving system may start as few as possible provided that the actual running requirement is satisfied; in another aspect, when the driving system of the electric vehicle is switched between the two-wheel drive and the four-wheel drive, the total target torque will not be changed, which may ensure a smoothness for the power and a comfort for the passenger.
• Fig. 9 is a logic flow chart showing a method for controlling the driving system of the electric vehicle to switch between the two-wheel drive and the four-wheel drive. Specifically, the method comprises following steps.
• step S901 after the charging of the electric vehicle is finished, the electric vehicle gets ready to run.
• step S902 the throttle pedal is trampled down, and the vehicle management system controller 600 judges whether the throttle depth signal is received. If no, the judging is continued. If yes, step S903 is followed.
• step S903 it is judged that whether the difference between the target speed and the current speed is larger than A. If yes, step S904 is executed. If no, step S906 is executed. At step S904, the power requirement of the electric vehicle is calculated, and the power is distributed to the two first motor controllers 300 and the two second motor controllers 500.
• each motor controller receives the power signal and drives a corresponding in-wheel motor according to the power signal.
• step S906 when the target speed V is reached, the second in-wheel motors 400 stop.
• step S907 the electric vehicle runs at a constant speed.
• step S908 the throttle pedal is released or the braking pedal is trampled down.
• step S909 an energy is regenerated by a drive of the primary in-wheel driving system.
• step S910 the speed is reduced or the electric vehicle stops, and step S902 is followed.
• the two motors when the trampling depth of the accelerator pedal reaches 70%, the two motors output maximal torques. When the trampling depth of the accelerator pedal is beyond 70%, the total torque of the electric vehicle are also outputted directly proportional to the trampling depth of the accelerator pedal, and the four motors output torque in the same state to supply power to the electric vehicle.
• the total torque when the trampling depth of the accelerator pedal reaches 70%, the total torque is 1000N ⁇ M, and the torque output of a single motor is 500N ⁇ M; and when the throttle opening rate is 72%, the total torque may be 1200N ⁇ M, and the torque output of the single motor is 300N ⁇ M.
• the two motors when the trampling depth of the accelerator pedal reaches back to 50%, the two motors output maximal torques.
• the opening rate of the throttle is beyond 70%, the total torque of the electric vehicle is directly proportional to the opening rate of the throttle, and the four motors output torque in the same state to supply power to the electric vehicle.
• the opening rate of the throttle is 50%
• the total torque is 800N ⁇ M
• the torque output of the single motor is 400N ⁇ M.
• the vehicle management system controller calculates speeds of an inner wheel and an outer wheel according to a rotation angle of the electric vehicle; and controls one or more first in-wheel motors and one or more second in-wheel motors corresponding to the inner wheel and one or more first in-wheel motors and one or more second in-wheel motors corresponding to the outer wheel respectively according to the speeds of the inner wheel and the outer wheel.
• a left driving wheel and a right driving wheel are required to rotate with different rotation speeds, which is realized by a mechanical differential.
• An inner friction torque of the mechanical differential is so small that torques of a left-half axis and a right-half axis may be approximately regarded as equal. Therefore, a same solution may be used in the driving system of the electric vehicle according to embodiments of the present disclosure, that is, the four motors are given a same torque, while an inner wheel and an outer wheel are provided with different rotation speeds to realize a speed differential.
• Fig. 13 is a schematic diagram of a model of a four-wheel electric vehicle. As shown in Fig. 13, ⁇ is an angle between a line from an instant center at a turning axis to the inner wheel and a middle axis of a primary in- wheel drive axle and an assistant in- wheel drive axle, and ⁇ is an angle between the turning axis and a line from the instant center at the turning axis to the outer wheel. For a same model of electric vehicle, the two angles are known.
• L 3 is an axis distance of the inner and outer wheels
• Li is an axis distance from the middle axis of the primary in- wheel drive axle and the assistant in-wheel drive axle to a front wheel
• ⁇ o is an angular speed when the electric vehicle turns
• ⁇ ⁇ , v 2 , v 3 , v 4 are rotation speeds of the four driving wheels respectively.
• the target speed of the inner wheel and the target speed of the outer wheel are calculated by following formulas:
• Fig. 14 is a flow chart of a method for controlling the speed differential of the electric vehicle.
• the method comprises following steps.
• step SI 401 the electric vehicle runs normally.
• step S1402 it is judged whether the electric vehicle is ready to turn. If no, the judging is continued. If yes, step SI 403 is followed.
• a rotation angle and a rotation direction are calculated.
• step S1404 a linear distance from the instant center to the electric vehicle is calculated.
• step SI 405 the rotation speeds of the inner wheel and the outer wheel are calculated.
• step S1406 the target rotation speed of each motor is calculated.
• the target speed and the torque are calculated via the trampling depth of the throttle pedal.
• step S1408 the power requirement of each motor is calculated according to the target speed and the torque.
• the driving system of the electric vehicle may have advantages of the electric vehicle and the four-wheel driving system.
• torques acting on a left wheel and a right wheel may be adjusted in time via an independent control of a left in-wheel motor and a right in-wheel motor, which may increase a driving efficiency, improve a transverse oscillation, more effectively apply a pulling force and a steering force to a wheel, and obtain a relatively high stability and driving safety.
• the method is easy to operate, low in cost and easy to industrialize.
• Any procedure or method described in the flow charts or described in any other way herein may be understood to comprise one or more modules, portions or parts for storing executable codes that realize particular logic functions or procedures.
• preferred embodiments of the present disclosure comprise other implementations in which the order of execution is different from that which is depicted or discussed, including executing functions in a substantially simultaneous manner or in an opposite order according to the related functions. This should be understood by those skilled in the art to which embodiments of the present disclosure belong.
• the logic and/or step described in other manners herein or shown in the flow chart, for example, a particular sequence table of executable instructions for realizing the logical function may be specifically achieved in any computer readable medium to be used by the instruction execution system, device or equipment (such as the system based on computers, the system comprising processors or other systems capable of obtaining the instruction from the instruction execution system, device and equipment and executing the instruction), or to be used in combination with the instruction execution system, device and equipment.
• the computer readable medium may be any device adaptive for including, storing, communicating, propagating or transferring programs to be used by or in combination with the instruction execution system, device or equipment.
• the computer readable medium comprise but are not limited to: an electronic connection (an electronic device) with one or more wires, a portable computer enclosure (a magnetic device), a random access memory (RAM), a read only memory (ROM), an erasable programmable read-only memory (EPROM or a flash memory), an optical fiber device and a portable compact disk read-only memory (CDROM).
• the computer readable medium may even be a paper or other appropriate medium capable of printing programs thereon, this is because, for example, the paper or other appropriate medium may be optically scanned and then edited, decrypted or processed with other appropriate methods when necessary to obtain the programs in an electric manner, and then the programs may be stored in the computer memories.
• each part of the present disclosure may be realized by the hardware, software, firmware or their combination.
• a plurality of steps or methods may be realized by the software or firmware stored in the memory and executed by the appropriate instruction execution system.
• the steps or methods may be realized by one or a combination of the following techniques known in the art: a discrete logic circuit having a logic gate circuit for realizing a logic function of a data signal, an application-specific integrated circuit having an appropriate combination logic gate circuit, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.
• each function cell of the embodiments of the present disclosure may be integrated in a processing module, or these cells may be separate physical existence, or two or more cells are integrated in a processing module.
• the integrated module may be realized in a form of hardware or in a form of software function modules. When the integrated module is realized in a form of software function module and is sold or used as a standalone product, the integrated module may be stored in a computer readable storage medium.
• the storage medium mentioned above may be read-only memories, magnetic disks or CD, etc.

Landscapes

• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Development (AREA)
• Sustainable Energy (AREA)
• Electric Propulsion And Braking For Vehicles (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=50987225

Family Applications (1)

Country Status (3)

Cited By (2)

Families Citing this family (17)

Citations (4)

Family Cites Families (8)

• 2012
  • 2012-12-27 CN CN201210580360.4A patent/CN103895524B/zh active Active
• 2013
  • 2013-12-27 WO PCT/CN2013/090730 patent/WO2014101838A1/en active Application Filing
• 2014
  • 2014-12-08 HK HK14112320.0A patent/HK1198823A1/zh unknown

Patent Citations (4)

Also Published As

Similar Documents

Legal Events