CN108146423B

CN108146423B - Steering, anti-tilting and driving integrated wheel electric driving system and control method

Info

Publication number: CN108146423B
Application number: CN201810132234.XA
Authority: CN
Inventors: 王军年; 罗正; 杨斌; 王凯; 郭德东; 刘培祥
Original assignee: Jilin University
Current assignee: Jilin University
Priority date: 2018-02-09
Filing date: 2018-02-09
Publication date: 2023-07-21
Anticipated expiration: 2038-02-09
Also published as: CN108146423A

Abstract

The invention discloses a steering, anti-tilting and driving integrated wheel-side electric driving system, which comprises: the output end of the outer rotor of the double-rotor motor is connected with the wheels, and the output end of the inner rotor is connected with the driving gear; an anti-tilting gear which is positioned at one side of the driving gear and is meshed with the driving gear; one end of the L-shaped anti-tilting rod is fixedly connected with the anti-tilting gear through a first clutch, and the other end of the L-shaped anti-tilting rod is connected with a suspension; the linear motor is fixed on one side of the double-rotor motor, and the secondary end of the linear motor is connected with the steering tie rod and used for driving the steering tie rod to move so as to realize steering; when the first clutch is combined, the output end of the inner rotor generates a resisting moment for preventing the suspension from jumping up and down, so that anti-tilting is realized. The steering, anti-tilting and driving integrated wheel-side electric driving system provided by the invention improves the integration of the system, saves the space and is convenient for the whole vehicle arrangement.

Description

Steering, anti-tilting and driving integrated wheel electric driving system and control method

Technical Field

The invention belongs to the technical field of automobile wheel side driving, and particularly relates to a steering, anti-tilting and driving integrated wheel side electric driving system and a control method.

Background

The traditional centralized driving type pure electric automobile adopts a power assembly formed by a single motor and a driving axle or a power assembly formed by a single motor, a transmission and a driving axle to drive the automobile to run, and has the advantages of more transmission parts, low transmission efficiency and large occupied space.

The hub drive or the wheel rim drive is characterized in that a driving motor is directly arranged in or near a driving wheel, and the motor directly drives the wheel or through a speed reducing mechanism. Compared with the traditional automobile, the automobile omits mechanical transmission parts such as a differential mechanism, has high transmission efficiency, compact structure and high utilization rate of the automobile body space, and simultaneously, each driving wheel can be independently controlled, so that the complex dynamic performance and stability control can be conveniently realized. However, in the case of a hub drive or a rim drive in which the drive motor is disposed on the wheel carrier, the ride comfort of the vehicle is poor due to the increased unsprung mass of the drive motor. Therefore, the problem can be effectively solved at the present stage by adopting an independent driving mode of the driving motor wheel edge arranged on the frame.

At the same time, existing wheel side drive systems are often also used in combination with conventional steering systems and suspension systems, which are relatively independent of the design and arrangement of the steering system and suspension system. When the traditional driving mode is changed into the wheel-side driving mode, the problems of space and motion interference among three systems often exist, and therefore, the design difficulty of the whole vehicle chassis system is high and the period is long. In addition, the conventional stabilizer bar in the suspension system needs to be connected with left and right independent suspension damper arms, which can effectively prevent the roll of the vehicle body, but also sacrifice part of riding comfort and increase the difficulty of space arrangement. The existing independent anti-tilting technology is mainly to add anti-tilting motors for all suspensions respectively, and is large in occupied space and complex in structure. In addition, although the independent steering technology of each wheel exists at present, the problem of failure of an independent steering executing component is not considered in the existing independent steering technology, and when the independent steering of one wheel fails, the whole vehicle cannot continue to finish steering action, so that the safety hidden trouble is high.

Disclosure of Invention

The invention aims to provide a steering, anti-tilting and driving integrated wheel-side electric driving system, which utilizes two special motors, namely a double-rotor motor and a linear motor, as two execution mechanisms to realize three functions of independent drive-by-wire, independent steering-by-wire and independent anti-tilting of wheels; the system has the advantages of improving the integration of the system, saving the space, facilitating the arrangement of the whole vehicle, realizing the independent steering control of each wheel and leading the steering to be more flexible.

The invention also aims to provide a control method of the steering, anti-tilting and driving integrated wheel-side electric driving system, which ensures reliable steering safety by controlling the on-off of the double-rotor motor and the clutch to realize the redundancy of steer-by-wire when the steering linear motor fails.

The technical scheme provided by the invention is as follows:

the output end of the outer rotor of the double-rotor motor is connected with the wheels, and the output end of the inner rotor is connected with the driving gear;

an anti-tilting gear which is positioned at one side of the driving gear and is meshed with the driving gear;

one end of the L-shaped anti-tilting rod is fixedly connected with the anti-tilting gear through a first clutch, and the other end of the L-shaped anti-tilting rod is connected with a suspension;

the linear motor is fixed on one side of the double-rotor motor, and the secondary end of the linear motor is connected with the steering tie rod and used for driving the steering tie rod to move so as to realize steering;

When the first clutch is combined, the output end of the inner rotor generates a resisting moment for preventing the suspension from jumping up and down, so that anti-tilting is realized.

Preferably, the steering, anti-tilting and driving integrated wheel-side electric driving system further comprises a failure protection mechanism, which comprises:

a steering gear which is positioned at the other side of the driving gear and is meshed with the driving gear;

the driving end of the second clutch is connected with the extending end of the steering gear;

a nut connected to the second clutch driven end;

the screw shaft is fixedly connected with one end, close to the steering gear, of the secondary side of the linear motor;

when the second clutch is closed, the steering gear rotates to drive the steering tie rod to move.

Preferably, the steering gear is sleeved on the nut through a needle bearing.

Preferably, the L-shaped anti-tilting rod comprises a first section and a second section which are perpendicular to each other, and the second section can rotate around the first section; the first section is connected with the first clutch, and the second section is connected with the shock absorber.

Preferably, the steering, anti-tilting and driving integrated wheel side electric driving system further comprises an anti-tilting connecting rod, wherein the lower end of the anti-tilting connecting rod is hinged with the end part of the second section, and the upper end of the anti-tilting connecting rod is hinged with the shock absorber.

Preferably, the driving end of the first clutch is connected with the extending end of the anti-tilting gear, and the driven end is connected with the first section end of the L-shaped anti-tilting rod.

Preferably, the anti-tilting gear is sleeved at the end part of the first section of the L-shaped anti-tilting rod through a needle bearing.

A control method of a steering, anti-tilting and driving integrated wheel-side electric driving system comprises the following steps:

the ECU reads the self-checking signal and judges whether the linear motor has a fault or not;

when the linear motor is in fault and a steering signal is input, the second clutch is controlled to be closed, the inner rotor of the double-rotor motor drives to work, torque is output according to the requirement of a driver, and the steering gear rotates to drive the steering wheels to steer;

when the linear motor fails and no steering signal is input, the second clutch is controlled to be closed, the inner rotor of the double-rotor motor outputs a locked torque which keeps static, the steering wheels are locked, and the linear running of the automobile is maintained.

Preferably, the control method of the steering, anti-tilting and driving integrated wheel-side electric driving system further comprises the following steps: when the system has no fault, the linear motor controls the steering of the automobile according to the steering requirement of a driver; the output section of the outer rotor of the double-rotor motor outputs torque to drive the vehicle to run or outputs electromagnetic braking torque to electrically brake the automobile to reduce the speed; the output end of the inner rotor of the double-rotor motor can generate a resistance moment for preventing the suspension from jumping up and down to realize anti-tilting.

Preferably, the control method of the steering, anti-tilting and driving integrated wheel-side electric driving system further comprises the steps of judging the road surface condition according to the running road surface mode switching signal and controlling the rigidity of the suspension according to the road surface condition;

if the road surface is good, the first clutch keeps a normally closed combination state or semi-linkage, and the roll stiffness of the suspension and the linear stiffness of the suspension at the side are controlled, and at the moment, the suspension stiffness is large or larger;

if the road surface is bad, the first clutch is controlled to be disconnected, the second clutch is restored to a normally-disconnected state, and the rigidity of the suspension is low.

The beneficial effects of the invention are as follows:

1. the steering, anti-tilting and driving integrated wheel side electric driving system provided by the invention realizes the integration of the steering function and the independent anti-tilting function besides the driving function of the traditional wheel side driving system by using the double-rotor motor and the linear motor, and has good system integration.

2. Compared with the traditional mechanical rear wheel steering system, the steering, anti-tilting and driving integrated wheel-side electric driving system provided by the invention omits a series of complicated steering transmission mechanisms; compared with the existing independent anti-tilting system, the system omits an execution motor or a hydraulic system, greatly simplifies the system structure and saves the available space and cost of the whole vehicle.

3. The steering, anti-tilting and driving integrated wheel side electric driving system provided by the invention can realize independent steering and independent driving of each wheel with single shaft, double shafts or multiple shafts and independent anti-tilting integration according to the arrangement space of the whole vehicle and the selected driving mode, and realize an electric chassis.

4. The steering, anti-tilting and driving integrated wheel side electric driving system provided by the invention can independently control the rigidity of the left and right side suspensions at the same time, can provide independent anti-tilting torsion moment for the left and right suspensions, and realizes accurate control for preventing the vehicle body from tilting; meanwhile, the control of the rigidity of the suspension can be further realized, and meanwhile, the automatic decoupling of the left suspension and the right suspension can be realized without a mechanical structure, so that the whole vehicle has better comfort; meanwhile, the invention realizes independent anti-tilting of the two-side suspension and independent suspension rigidity adjustment, and can timely and accurately adjust the suspension rigidity according to the road surface condition and the vehicle body state, thereby effectively improving the comfort.

5. The steering, anti-tilting and driving integrated wheel-side electric driving system provided by the invention is not mechanically connected with the steering wheel, is a steer-by-wire system, can flexibly adjust the angle transmission ratio of the steering system according to factors such as the speed of a vehicle and the state of the vehicle, and greatly improves the steering performance of the automobile. In addition, in order to ensure the reliability of the steer-by-wire system, two sets of mechanisms of the double-rotor motor and the linear motor for steering are used for realizing redundant steer-by-wire by parallel operation, so that the steering safety is ensured.

Drawings

Fig. 1 is a schematic diagram of the overall structure of the steering, anti-tilting and driving integrated wheel-side electric driving system according to the present invention.

Fig. 2 is a schematic diagram of the structural principle of the steering, anti-tilting and driving integrated wheel-side electric driving system according to the invention.

Fig. 3 is a schematic structural view of an anti-tilting connecting rod of the steering, anti-tilting and driving integrated wheel-side electric driving system according to the present invention.

Fig. 4 is a schematic structural diagram of an anti-tilting gear of the steering, anti-tilting and driving integrated wheel-side electric driving system according to the present invention.

Fig. 5 is a schematic structural view of a ball screw mechanism of a steering, anti-tilting and driving integrated wheel-side electric driving system according to the present invention.

Fig. 6 is a schematic diagram of an outer rotor structure of a dual-rotor motor of a steering, anti-tilting and driving integrated wheel-side electric driving system according to the present invention.

Fig. 7 is a schematic diagram of the electrical connection between the steering, anti-roll and drive integrated wheel-side electric drive system according to the present invention.

Fig. 8 is a flowchart of a control method of a steering, anti-tilting and driving integrated wheel-side electric driving system according to the present invention.

Detailed Description

The present invention is described in further detail below with reference to the drawings to enable those skilled in the art to practice the invention by referring to the description.

As shown in fig. 1-2, the present invention provides a steering, anti-roll and drive integrated wheel side electric drive system, which includes an L-shaped anti-roll bar 200, an anti-roll bar 210, a dual rotor motor 600, a linear motor 400, a planetary gear reduction 800, a ball screw mechanism 500, a drive gear 700, a steering gear 560, an anti-roll gear 230, a first clutch 220, a second clutch 550, a knuckle 110, an inner universal joint 150, an outer universal joint 130, an inner half shaft 140, an outer half shaft 120, a tie rod 300, a damper 160, and a wheel side drive housing 900.

As shown in fig. 2, the dual-rotor motor 600 has a double-end output structure, the output end of the outer rotor 640 of the dual-rotor motor is connected with the sun gear 820 of the planetary gear reducer 800 through a spline, and the output end of the inner rotor 630 is connected with the driving gear 700 through a spline. The center of the planet carrier 840 of the planetary gear reduction device 800 is connected to the input end of the inner joint 150, and the ring gear 830 of the planetary gear reduction device 800 is fixed to the wheel side drive housing 900. The output of the inner joint 150 is connected to the inner axle shaft 140, and the inner axle shaft 140 is connected to the outer axle shaft 120 via the outer joint 130. The inner 150 and outer 130 universal joints are equal angular velocity universal joints. The journal portion of the knuckle 110 is hollow and the outer axle shaft 120 passes through the hollow journal center of the knuckle 110 to facilitate the transfer of torque through the outer axle shaft 120 to the hub connection of the wheel 100. The outer end of the outer half shaft 120 is provided with a flange, six uniformly distributed bolts are arranged on the flange, and the flange of the outer half shaft 120 is fixedly connected with the hub of the wheel 100 through bolts and nuts, so that the outer half shaft 120 can drive the wheel 100 to rotate.

The L-shaped anti-tilting bar 200 comprises a first section and a second section which are perpendicular to each other, and the second section can rotate around the first section; the first segment portion is inserted and supported within the wheel drive housing 900 and is free to rotate relative to the wheel drive housing 900. The first section is connected to the driven end of the first clutch 220, and the end of the first section is further sleeved with an anti-tilting gear 230 through a needle bearing, where the anti-tilting gear 230 can freely rotate on the L-shaped anti-tilting bar 200. The second end is connected to the lower end of the anti-tilting connecting rod 210 through a ball pin, and the upper end of the anti-tilting connecting rod 210 is connected to the lug part at the lower end of the arm of the damper 160 through a ball pin. The L-shaped anti-roll bar 200 is made of spring steel or other alloy materials.

The anti-tilting gear 230 is located at one side of the driving gear 700 in the horizontal direction, and the protruding end of the anti-tilting gear 230 is connected with the driving end 222 of the first clutch 220. The anti-tilting gear 230 is engaged with the driving gear 700, and the output end of the inner rotor 630 of the dual rotor motor 600 is connected with the driving gear 700 through a spline.

As shown in fig. 1 and 3, in this embodiment, the anti-tilting connecting rod 210 is a straight rod, two ends have lugs, and the centers of the lug structures at two ends are provided with pin holes. The upper end of the anti-tilting connecting rod 210 is connected with a lug on the arm of the shock absorber 160 through a ball pin, and the lower end is connected with the outer end of the L-shaped anti-tilting rod 200 through a ball pin.

In this embodiment, as shown in fig. 4, the anti-tilting gear 230 is a cylindrical straight gear, one side of which is processed with an extending end, the center of the extending end and the gear body is processed with a through hole, and the outer diameter of the end of the extending end is processed with a spline for spline fit with the friction plate of the driving end 222 of the first clutch 220. The anti-roll gear is meshed with the drive gear 700. The anti-tilting gear 230 is hollow and sleeved on the L-shaped anti-tilting bar 200 through a needle bearing.

The first clutch 220 is an electrically controlled normally closed clutch, and when the first clutch 220 is combined, the rotation of the L-shaped anti-tilting lever 200 drives the anti-tilting gear 230 to rotate, so that the connection between the dual-rotor motor 600 and the L-shaped anti-tilting lever 200 is realized. When the first clutch 220 is disengaged, the anti roll gear 230 is free to rotate on the L-shaped anti roll bar 200.

The first clutch 220 may be an electromagnetic multi-plate clutch, an electrically controlled hydraulic clutch, or other electrically controlled clutch as required, which is not intended to limit the scope of the invention.

In this embodiment, the driving gear 700 and the anti-tilting gear 230 form a speed-reducing and torque-increasing device, that is, a fixed gear is used to realize speed reduction and torque increase. In other embodiments, other reduction devices or mechanisms, such as a secondary fixed gear drive or planetary gear mechanism, are selected as desired at the output of the L-shaped anti roll bar 200 and the inner rotor 630 of the dual rotor motor 600.

The linear motor 400 includes a secondary and a primary, the primary is powered by alternating current, and the secondary moves linearly along the primary under the action of electromagnetic force. The linear motor 400 is fixed to the wheel side driving device housing 900, one end of the tie rod 300 is connected to one end of the secondary of the linear motor 400 through a ball head, and the other end is connected to the knuckle 110 through a ball head pin, so that the linear motor 400 can be controlled to make the secondary move linearly, and the tie rod 300 is pulled to move horizontally, and the movement of the tie rod 300 can rotate the wheels 100.

In the present embodiment, a steering failure protection mechanism is further included, which is composed of the ball screw mechanism 500, the second clutch 550, and the steering gear 560. The steering gear 560 is a spur gear which is located at the other side (the side opposite to the anti-tilting gear 230) of the driving gear 700 in the horizontal direction, and the steering gear 560 has the same structure as the anti-tilting gear 230. The steering gear 560 is meshed with the drive gear 700 and is hollow over the ball screw mechanism nut 510 via a needle bearing. While the extended end of the steering gear 560 is connected to the drive end 552 of the second clutch 550.

As shown in fig. 2 and 5, the ball screw mechanism 500 includes a ball 520, a screw shaft 530, and a ball screw mechanism nut 510. The screw ball screw mechanism nut 510 is connected with the driven end 551 of the second clutch 550 through an end flange and a steering gear 560 is sleeved on the ball screw mechanism nut 510 through a needle bearing, and the steering gear 560 can freely rotate on the ball screw mechanism nut 510. While the projecting end of the steering gear 560 is splined to the drive end 552 of the second clutch. The ball screw mechanism nut 510 is limited in the degree of freedom of movement along the screw shaft 530, and the ball screw mechanism nut 510 can only rotate about its axis, thus converting the rotational movement of the ball screw mechanism nut 510 into linear movement of the screw shaft 530. The screw shaft 530 and the other secondary end (the end which is not connected with the tie rod 300) of the linear motor 400 are of an integrated structure, and a semicircular rotary spiral groove is processed on the screw shaft 530 and is used as a rolling track of the ball 520; the inner wall of the center of the ball screw mechanism nut 510 is processed with a semicircular rotary spiral groove corresponding to the screw shaft 530 for assembling the balls 520 and as a track along which the balls 520 slide. Meanwhile, an inner circulation channel of the ball 520 is also machined in the inner wall of the nut 510 along the axial direction, the inlet and the outlet of the channel are respectively at the position close to the starting point and the end point of the semicircular spiral groove, and the ball circulation channel enables the ball 520 to circularly roll in the track, so that the rotation of the nut 510 of the ball screw mechanism is converted into the linear motion of the screw shaft 530. In addition, a flange is machined at one end of the ball screw mechanism nut 510, and six through holes are uniformly machined in the flange along the axial circumference for connection with the driven end of the second clutch 550 through bolts.

The second clutch 550 is an electrically controlled normally open clutch, when the second clutch 550 is disconnected, the steering gear 560 can rotate freely on the ball screw mechanism nut 510, and when the second clutch 550 is combined, the rotation of the steering gear 560 drives the rotation of the ball screw mechanism nut 510, so as to drive the screw shaft 530 to move horizontally.

The second clutch 550 may be an electromagnetic multi-plate clutch, an electrically controlled hydraulic clutch, or the like, as required, which is not intended to limit the scope of the present invention.

The driving gear 700 and the steering gear 560 form a speed-reducing and torque-increasing device, the fixed gear transmission selected by the invention is the speed-reducing and torque-increasing device for the inner rotor 630 of the double-rotor motor 600 to drive the wheel 100 to rotate around the main pin, and other speed-reducing devices or mechanisms can be selected at the output ends of the steering gear 560 and the inner rotor 630 of the double-rotor motor 600 according to the requirement, and the invention does not limit the protection scope of the invention.

As shown in fig. 2, the dual rotor motor 600 includes a housing 670, an outer rotor 640, an inner rotor 630, permanent magnets 660, field windings 620, a stator 620, and armature windings 650. Wherein the outer casing 670 is configured to house the outer rotor 640 and the inner rotor 630; permanent magnets 660 uniformly distributed in groups are attached to the inner and outer side surfaces of the outer rotor 640; the stator 610 is fixed on the inner wall of the housing 670; an excitation winding 620 is mounted on the stator 610: an armature winding 650 is mounted on the inner rotor 630. As shown in fig. 6, in the present embodiment, the outer rotor 640 of the dual rotor motor 600 includes a main body 641 and an end cover 642 that are engaged with each other by using a jaw. The center of the end face of the main body 641 is provided with a stepped through hole composed of a bearing hole having a larger inner diameter and a light hole having a smaller inner diameter, the bearing hole being for mounting the right support bearing of the inner rotor 630, and the output end of the inner rotor 630 protruding from the stepped through hole. The inner side of the bottom of the end cover 642 is processed with a bearing counter bore for mounting the right support bearing of the inner rotor 630. The inner rotor 630 is nested in the accommodating space formed by the jaw-type body 641 and the end cover 642 which are matched with each other.

During installation, the left and right support bearings of the inner rotor 630 are installed in the corresponding bearing holes at the bottoms of the main body 641 and the end cover 642 of the outer rotor 640, the inner rotor 630 is placed in the main body 641 of the outer rotor 640, the end cover 642 of the outer rotor is sleeved, and the outer rotor 640 and the inner rotor 630 are integrally installed in the double-rotor steering motor housing 670. The dual rotor motor housing 670 is secured within the wheel drive housing 900 and integrally secured to the vehicle subframe, and is of sprung mass.

In another embodiment, as shown in fig. 6, six arc trapezoid groove teeth are processed on the circumference of the matching part of one end of the main body 641 of the outer rotor 640 of the dual-rotor motor and the end cover 642, namely, the size of the groove teeth at the radial center-near end is smaller than that of the groove teeth at the far center end, and the tooth root plane of the groove teeth of the main body 641 is also processed with an arc-shaped small groove of a circular ring; six arc trapezoid raised teeth are machined at the positions of the end cover 642 corresponding to the six arc trapezoid grooves of the main body 641, the size of the raised teeth is smaller than that of the far circle center end at the radial circle center end, annular arc-shaped protrusions corresponding to small grooves at the tooth heels of the arc trapezoid grooves of the main body are machined on the tooth top plane of the arc trapezoid raised teeth of the end cover 642, and the basic sizes of the arc trapezoid protrusions and the arc trapezoid grooves are the same. When the main body 641 and the end cover 642 are combined into the outer rotor 640, the circular arc trapezoidal groove teeth of the main body 641 and the tooth profile two sides of the circular arc trapezoidal protruding teeth of the corresponding end cover are matched and positioned to play a role in radial positioning, so that the centers of the main body 641 and the end cover are centered, the small grooves of the tooth roots and the circular arc-shaped protrusions of the tooth tops of the main body 641 and the end cover 642 are in clearance fit correspondingly in pairs, the functions of auxiliary radial limiting and axial positioning are achieved, and reliable centering during tooth fitting of the main body 641 and the end cover 642 is ensured.

The planetary gear mechanism reduction gear 800 includes a sun gear 820, a ring gear 830, planet gears 840, and a carrier 810. The sun gear 820 is connected to the output end of the inner rotor 630 of the dual-rotor motor 600 through a spline, the planet carrier 810 is used as output, and the center of the planet carrier 810 is connected to the input end of the inner universal joint 150 through a spline. The ring gear 830 is fixed to the housing 900 of the wheel side drive. The planet carrier 810 has mounted thereon planet gears 840, preferably the present invention has mounted thereon 3 planet gears 840,

the planetary gears 840 are rotatable while revolving around the sun gear 820 between the sun gear 820 and the ring gear 830. The planetary gear reduction device 800 plays a role in reducing and increasing torque for the output torque of the outer rotor 640 of the dual-rotor motor.

The present embodiment selects the planetary gear reduction device 800 as the speed and torque reduction device for the outer rotor 640 of the dual rotor motor 600 to drive the wheel 100. In other embodiments, other speed reducing devices and mechanisms may be used between the wheel 100 and the dual rotor motor 600 as desired, and this is not a limitation on the scope of the claimed invention.

The wheel driving device housing 900 is divided into a left cavity and a right cavity, the left cavity is used for accommodating and supporting the dual-rotor motor 600 and the linear motor 400, and the right cavity is used for accommodating and supporting the ball screw mechanism 500, the first clutch 220, the second clutch 550, the driving gear 700, the anti-tilting gear 230 and the steering gear 560. The left cavity adopts a plurality of hollow designs, and heat dissipation ribs are cast on the solid part of the shell, so that the external air flows into the inner cavity of the shell when the vehicle runs, and the dual-rotor motor 600 and the linear motor 400 are cooled. The right side cavity is of a closed design and contains gear oil for lubricating the gear set and cooling and providing working pressure oil (oil pump not shown) to the first clutch 220 and the second clutch 550. The wheel side driving apparatus housing 900 is fixed to a frame or sub-frame, belongs to a sprung mass, does not increase an unsprung mass, and does not influence ride comfort of the whole vehicle.

In another embodiment, as shown in fig. 7, the steering, tilting and driving integrated wheel-side electric driving system further includes an Electronic Controller (ECU) 950, where the ECU950 may be provided separately or may be integrated in a vehicle controller. The ECU950 is electrically connected to the dual rotor motor 600, the linear motor 400, the first clutch 220, and the second clutch 550, and can control the operations of the four actuators. The ECU can read the detection signals in the dual rotor motor 600 and the linear motor 400 to determine whether a fault occurs. Meanwhile, the ECU950 CAN be connected to the CAN bus of the whole vehicle, communicate with the controller of the whole vehicle, and CAN receive driver demand signals such as driving, steering and a vehicle running mode switch selected by a driver according to road surface conditions in the CAN bus, and vehicle state signals such as vehicle speed, lateral acceleration, vehicle body side inclination angle and the like. Deciding a plurality of sets of outer rotor driving torque, linear motor torque and displacement of the double-rotor motor of the wheel-side electric driving system according to the driver demand signals; the driving road condition is judged according to the driving mode switch signals input by a driver, the signals such as the vehicle speed, the lateral acceleration and the like, the combination and half-linkage or disconnection states of the first clutch and the combination and disconnection states of the second clutch are decided, and the driving or locked torque of the inner rotor of the double-rotor motor of the system is decided according to the vehicle speed, the vehicle body side inclination angle and the lateral acceleration signals.

The steering, anti-tilting and driving integrated wheel-side electric driving system provided by the invention presents a plurality of working modes according to whether an executing mechanism fails and the type of failure, and is specifically shown in the following table:

the working principle under each mode is as follows:

in the normal operation mode, the outer rotor 640 of the dual rotor motor 600 is controlled to generate a driving torque, and the driving torque is transmitted to the hub of the wheel 100 through the planetary gear reduction 800, the inner universal joint 150, the inner half shaft 140, the outer universal joint 130 and the outer half shaft 120, so as to drive the wheel 100 to rotate.

In the steering, anti-tilting and driving integrated wheel-side electric driving system provided by the invention, because the outer rotor 640 of the actuator double-rotor motor 600 belongs to a relatively independent driving system, when the outer rotor 640 of the double-rotor motor 600 fails singly, the operation of the four actuators (the outer rotor of the double-rotor motor, the linear motor, the first clutch and the second clutch) disclosed by the invention is not influenced. For the failure condition of the driving system, the vehicle driving controller for controlling the independent driving of a plurality of wheels (namely, a plurality of sets of the wheel driving system provided by the invention are arranged on all wheel edges) is used for coordinately controlling the torque output of a plurality of wheels, so that the limp control for reducing the power is realized, and the safe driving to a fault maintenance site is ensured.

In the normal operation mode, the second clutch 550 is kept normally open and disconnected, the steering gear 560 idles on the ball screw mechanism nut 510, the first clutch 220 is kept normally closed, and the rotation of the anti-tilting gear 230 drives the rotation of the L-shaped anti-tilting lever 200. When steering is required, the linear motor 400 is controlled to make the secondary linear motion, so that the tie rod 300 is pulled, and the tie rod 300 drives the knuckle 110 to rotate the wheel 100, so that steering is completed. When the vehicle body is tilted or the rigidity of the suspension needs to be adjusted, the up-and-down runout of the suspension is converted into the up-and-down movement of the anti-tilting connecting rod 210, and then is converted into the rotation of the L-shaped anti-tilting rod 200, the inner rotor 630 of the dual-rotor motor 600 outputs the resistance moment in a controlled manner, and the resistance moment acts on the L-shaped anti-tilting rod 200 through the action of the driving gear 700, the anti-tilting gear 230 and the first clutch 220, so that the vehicle body is effectively restrained from tilting or the suspension rigidity is adjusted.

When the electronic controller ECU950 of the system detects that the linear motor 400 has a fault and failure, the second clutch 550 is controlled to be combined, and the steering gear 560 rotates to drive the ball screw mechanism nut 510 to rotate. There are two cases when the linear motor 400 fails:

the first case is that the inner rotor 630 of the dual-rotor motor 600 outputs a rotation moment (the inner rotor 630 can output a larger moment than the linear motor 400) if steering is required at this time. On the one hand, at this time, the second clutch 550 is controlled to combine the torque, and the torque is used as a driving torque to control the steering of the wheels through the second clutch 550, and the specific power transmission path is as follows: the torque is transmitted to the ball screw mechanism nut 510 through the driving gear 700, the steering gear 560 and the second clutch 550, so that the ball screw mechanism nut 510 is driven to rotate, the ball screw mechanism 500 converts the rotation of the ball screw mechanism nut 510 into the linear motion of the screw shaft 530, the steering tie rod 300 is pulled to move horizontally, the steering knuckle 110 is pulled to swing by the steering tie rod 300, the steering action of the wheels 100 is completed, and the steering safety of the whole vehicle after the failure of the linear motor 400 is effectively ensured. On the other hand, since the first clutch 220 is normally closed in this case, the inner rotor 630 of the dual rotor motor 600 outputs torque as a reverse resistance moment to suppress the roll of the vehicle body caused by steering through the first clutch 220. The specific power transmission path is as follows: the moment is transmitted to the L-shaped anti roll bar 200 through the driving gear 700, the anti roll gear 230 and the first clutch 220 to force the second section of the L-shaped anti roll bar 200 to swing around the first section, thereby driving the anti roll bar 210 to move up and down through the ball pin, and driving the extension or compression of the suspension. It should be noted that, the rotation direction of the ball track spiral line of the ball screw mechanism 500 should ensure that the angular velocity direction of the L-shaped anti-tilting bar 200 points to the inner side of the vehicle body when the wheels are driven to steer to the right side by the dual-rotor motor 600, that is, the anti-tilting connecting rod 210 moves upward to stretch the side suspension under the driving of the rotation of the L-shaped anti-tilting bar 200, so as to support the vehicle body to tilt to the side. The steering, anti-tilting and driving integrated wheel-side electric driving systems are respectively arranged on the wheels on the two coaxial sides, and when the wheels arranged on the two coaxial sides are matched for use, the moment output by the double-rotor motor on the other side pulls down the suspension, so that the inclination of the vehicle body to the other side is restrained. The principle is the same when the automobile turns to the left, and will not be described again. The combined action of the double-rotor motors on two sides can effectively and actively inhibit the rolling motion of the car body during the steering motion of the car, even realize zero rolling angle and improve the turning driving safety and rolling comfort of the car.

In addition, due to the importance and priority of the steering moment demand, the moment output by the inner rotor 630 of the dual rotor motor 600 cannot be adjusted according to the requirement of roll inhibition, and at this time, the rigidity of the side suspension can be adjusted by controlling the coupling degree of the first clutch 220, i.e., the semi-linkage state (realized by current control electromagnetic force or hydraulic control pressing force), so as to satisfy the roll control requirement and the suspension smoothness requirement under different vehicle speeds and road conditions. If the running road surface condition is good, the automobile runs at a higher speed, at the moment, the combination degree of the first clutch 220 is larger, the rigidity of the side suspension is larger, and the high-speed running stability of the automobile is good; if the driving condition is bad, such as off-road low-speed driving, the first clutch 220 is combined to a small extent, even completely disconnected, the rigidity of the side suspension is small or minimum, the grounding performance of the automobile tire is good, and the riding comfort is good.

The second case is that if steering is not required at this time, the inner rotor 630 of the dual rotor motor 600 outputs a locked torque that remains stationary. Since the second clutch 550 is controlled to combine the torque as a locked torque at this time, the torque is used by the second clutch 550 to resist unnecessary wheel steering caused by external disturbance, thereby ensuring straight running stability. The specific power transmission path is the same as in the case where steering is required. On the other hand, since the first clutch 220 is normally closed in this case, the moment also suppresses suspension deformation by the first clutch 220 as a locked torque. The specific power transmission path is the same as the case where steering is required, and will not be described again. The locked torque output from the inner rotor 630 of the dual rotor motor 600 forces the inner end of the L-shaped anti-roll bar 200 to be fixed, and the torsional rigidity of the L-shaped anti-roll bar 200 can increase the suspension rigidity, inhibiting the suspension from compressing or expanding. When the system is matched with two wheels arranged on two coaxial sides, the locked rotor moment output by the double-rotor motor on the other side can inhibit suspension expansion or compression, and the combined action of the double-rotor motors on the two sides can effectively inhibit the rolling motion of the vehicle body when the vehicle is interfered by lateral wind during the straight running, so that the straight running safety of the vehicle is improved. In this case, the roll angle is slightly larger than that in the case of steering, in order to passively suppress the roll of the vehicle body. It should be noted that, due to the importance and priority of the requirement of suppressing the disturbance steering moment to keep the straight running, the locked-rotor torque output by the inner rotor 630 of the above-mentioned dual-rotor motor 600 cannot be adjusted according to the requirement of the rolling suppression, and at this time, the rigidity of the side suspension can be adjusted by controlling the combination degree (the implementation of the current control electromagnetic force or the hydraulic control pressing force) of the first clutch 220, so as to give consideration to the rolling control requirement and the suspension smoothness requirement under different vehicle speeds and road conditions. In the limit situation, when the road conditions such as the low-speed walking on the non-paved road are worse, the first clutch 220 can be controlled to be completely disconnected, at this time, the L-shaped anti-tilting lever 200 is not in action, the rigidity of the suspension is reduced to the minimum, and the suspension presents soft characteristics so as to improve the running smoothness of the rotten road running.

The second clutch 550 is controlled to be engaged when the electronic controller ECU950 of the system detects that there is a failure of the inner rotor 630 of the dual rotor motor 600 and that the driver inputs a steering demand command through the steering wheel through the CAN bus. At this time, the electronic controller ECU950 controls the linear motor 400 to output a steering torque according to the driver input. The specific power transmission path is as follows: the linear motor 400 rotates about the wheel kingpin by dragging the knuckle 110 and the wheel 100 via the tie rod 300. The steering torque output from the linear motor 400 also pulls the screw shaft 530 of the fixedly connected ball screw mechanism 500 to translate, and the translation of the motion of the ball screw mechanism 500 changes the translation into the rotation of the nut 510. Under the combination of the second clutch 550, the nut 510 drives the steering gear 560 to rotate, and drives the anti-tilting gear 230 to rotate under the action of the driving gear 700 serving as an idler, and then drives the L-shaped anti-tilting lever 200 to actively swing around the axis of the L-shaped anti-tilting lever through the normally closed first clutch 220, so as to drive the anti-tilting connecting rod 210 to move up and down, and further drive the suspension to stretch or compress. Similarly, the rotation direction of the ball track spiral line of the ball screw mechanism 500 should ensure that the angular velocity direction of the L-shaped anti-tilting bar 200 points to the inside of the vehicle body when the wheel is driven to steer to the right by the linear motor 400, that is, the anti-tilting connecting rod 210 moves upwards to stretch the side suspension under the driving of the rotation of the L-shaped anti-tilting bar 200, so as to support the vehicle body to tilt to the side. When the two sets of systems are configured on two wheels on two coaxial sides for matching use, the moment output by the other side double-rotor motor (if the other side double-rotor motor also fails, the other side linear motor can also be used for outputting active anti-tilting moment) pulls down the suspension, and the inclination of the vehicle body to the other side is restrained. The principle is the same when the automobile turns to the left, and will not be described again. The linear motors on two sides can effectively and actively restrain the rolling motion of the car body during the steering motion of the car under the combined action of the gear mechanisms, even realize zero rolling angle and improve the turning driving safety and the rolling comfort of the car. It should be noted that, due to the importance and priority of the steering moment requirement, the moment output by the linear motor 400 cannot be adjusted according to the requirement of roll inhibition, and at this time, the stiffness of the side suspension can be adjusted by controlling the coupling degree of the first clutch 220, that is, the semi-linkage state (realized by current control electromagnetic force or hydraulic control pressing force), so as to satisfy the roll control requirement and the suspension smoothness requirement under different vehicle speeds and road conditions. In addition, in this mode, when the linear motor 400 drives and controls steering, a series of transmission components are required to drive the L-shaped anti-tilting rod 200 to act to realize active anti-tilting, which affects the dynamic response speed of steering control, so that when the requirement on dynamic response of steering is high, the second clutch 550 can be controlled to be disconnected, and the moment of inertia when the linear motor 400 acts is reduced. At the moment, the roll control is affected to a certain extent, and the design is specifically required to be calibrated according to the use condition and the matched vehicle type at the control system software level. If the driving road surface condition is good, the automobile runs at a higher speed, at this time, the first clutch 220 is restored to a normally closed state, the second clutch 550 is controlled to be closed, and the rigidity of the side suspension is ensured so as to meet the requirements of roll control and high-speed driving stability of the automobile; if the driving condition is bad, such as off-road low-speed driving, at this time, the first clutch 220 is controlled to be combined to a small extent, even to be completely disconnected, the second clutch 550 is controlled to be restored to a normally-disconnected state, the rigidity of the side suspension is small or minimum, the grounding performance of the automobile tire is good, and the riding comfort is good.

The second clutch 550 is controlled to engage when the electronic controller ECU950 of the system detects that there is a failure of the inner rotor 630 of the dual rotor motor 600 and no steering demand command by the driver is detected. At this time, the electronic controller ECU950 controls the linear motor 400 to output the locked torque which remains stationary. On the one hand, the locked torque drags the steering knuckle 110 and the wheels 100 through the tie rod 300 to resist external steering interference torque, keeps the wheels from rotating, and ensures the straight running stability; on the other hand, when the second clutch 550 is combined, the locked torque is transmitted to the anti-roll gear 230 through the second clutch 550, the steering gear 560 and the driving gear 700 serving as an idler gear, and then the first section of the L-shaped anti-roll bar 200 is forced to be fixed through the normally closed first clutch 220, so that the torsional rigidity of the L-shaped anti-roll bar 200 can increase the rigidity of the suspension, and the suspension is restrained from being compressed or stretched. When the system of the invention is configured on two wheels on two coaxial sides for matching use, the locked rotor moment output by the other side double-rotor motor (the other side linear motor can be used for outputting the passive locked rotor anti-tilting moment if the other side double-rotor motor also fails) can inhibit the suspension from stretching or compressing, and the two side linear motors can effectively inhibit the rolling motion of the vehicle body when the vehicle is interfered by side wind during the straight running of the vehicle through the combined action of the gear mechanism, so that the straight running safety of the vehicle is improved. In this case, the roll angle is slightly larger than that in the case of steering, in order to passively suppress the roll of the vehicle body. It should be noted that, due to the importance and priority of the requirement of suppressing the disturbance steering moment to keep the straight running, the locked-rotor moment output by the above-mentioned linear motor 400 cannot be adjusted according to the requirement of roll suppression, and at this time, the rigidity of the side suspension can be adjusted by controlling the degree of coupling of the first clutch 220, that is, the half-linkage state (realized by current control electromagnetic force or hydraulic control pressing force), so as to give consideration to the roll control requirement and the suspension smoothness requirement under different vehicle speeds and road conditions. In the limit situation, when the road conditions such as the low-speed walking on the non-paved road are worse, the first clutch 220 can be controlled to be completely disconnected, at this time, the L-shaped anti-tilting lever 200 is not in action, the rigidity of the suspension is reduced to the minimum, and the suspension presents soft characteristics so as to improve the running smoothness of the rotten road running. When the first clutch 220 is controlled to be completely disconnected, the second clutch 550 is also restored to the normally open state to reduce the locked-rotor inertia of the linear motor 400, so as to improve the rapid control responsiveness for maintaining the linear running.

The invention also provides a failure protection control method of the steering, anti-tilting and driving integrated wheel-side electric driving system, as shown in fig. 8, comprising the following steps:

step 1: the system program starts and initializes.

Step 2: the ECU reads the self-test signal.

Step 3: judging whether the system has a fault or not, and if so, performing step 4; if not, go to step 22.

Step 4: judging whether the dual-rotor motor has a fault or not, and if so, performing a step 5; if not, go to step 16.

Step 5: judging whether the double-rotor motor is an inner rotor fault or not, and if so, performing a step 6; if not, go to step 9.

Step 6: judging whether the linear motor has faults at the same time, if so, performing a step 7; if not, go to step 8.

Step 7: the ECU starts the system fault alarm and controls the whole car to slow down until safe stopping, and jumps to the final step 23.

Step 8: judging whether the outer rotor of the double-rotor motor also fails, if so, performing a step 9; if not, go to step 10.

Step 9: the ECU starts the whole vehicle limp control to stop the wheel side driving system arranged on one driving wheel side, and the other fault-free system drives the vehicle to safely continue to run to a maintenance station on the premise of ensuring stability. At this time, the total driving power of the whole vehicle cannot meet the requirements of drivers, and the power output is reduced to ensure safety. Finally, the process goes to the final step 23.

Step 10: judging whether the driver has steering input or not, if so, performing step 11; if not, go to step 12.

Step 11: the linear motor is driven to work, torque is output according to the requirement of a driver to drive the steering wheels to steer, and the step 13 is skipped.

Step 12: the linear motor stops rotating, the steering wheel is locked, the automobile is maintained to run in a straight line, and the step 13 is skipped.

Step 13: judging whether the road surface is a good road surface or not according to the driving road surface mode switch signal selected by the driver, and if so, performing step 14; if not, go to step 15.

Step 14: the first clutch is restored to a normally closed combined state or half-linked state, and the suspension roll stiffness and the current side suspension wire stiffness are controlled, and at the moment, the suspension stiffness is large or larger. Finally, the process goes to the final step 23.

Step 15: the first clutch is controlled to be disconnected, and the second clutch is restored to a normally-disconnected state, and at the moment, the rigidity of the suspension is small. Finally, the process goes to the final step 23.

Step 16: judging whether the driver has steering input or not, if so, performing step 17; if not, go to step 18.

Step 17: the second clutch is controlled to be closed, the inner rotor of the double-rotor motor is driven to work, the steering wheel is driven to steer according to the output torque required by the driver, and the step 19 is skipped.

Step 18: the second clutch is controlled to be closed, the inner rotor of the double-rotor motor is locked to work, the steering wheels are locked, the automobile is maintained to run in a straight line, and the step 19 is skipped.

Step 19: judging whether the road surface is a good road surface or not according to the driving road surface mode switch signal selected by the driver, and if so, performing step 20; if not, go to step 21.

Step 20: the first clutch is restored to a normally closed combined state or half-linked state, and the suspension roll stiffness and the current side suspension wire stiffness are controlled, and at the moment, the suspension stiffness is large or larger. Finally, the process goes to the final step 23.

Step 21: the first clutch is controlled to be disconnected, and the second clutch is restored to a normally-disconnected state, and at the moment, the rigidity of the suspension is small. Finally, the process goes to the final step 23.

Step 22: the system works normally. The linear motor 400 controls the steering of the automobile according to the steering requirement of the driver; the outer rotor 640 of the dual rotor motor 600 outputs torque to drive the vehicle to run or outputs electromagnetic braking torque to electrically brake the vehicle to decelerate; the inner rotor 630 of the dual-rotor motor 600 controls the torsional rigidity of the suspension transverse stabilizer bar, controls the linear rigidity of the suspension of the side to meet the requirements of the smoothness of the whole vehicle, and can be arranged on two sides.

Step 23: and (5) ending.

The steering, anti-tilting and driving integrated wheel-side electric driving system provided by the invention utilizes two special motors, namely a double-rotor motor and a linear motor, as two execution mechanisms to realize three functions of independent drive-by-wire, independent steering-by-wire and independent anti-tilting of wheels. Components such as a steering gear and a differential mechanism in the traditional automobile are omitted, the integration of the system is improved, the space is saved, the whole automobile is convenient to arrange, and meanwhile, independent steering control of each wheel is realized, so that steering is more flexible. The independent anti-tilting control of wheels at two sides is realized, the rolling of a vehicle body can be effectively prevented while the riding comfort is improved, and meanwhile, the control of actively promoting the rolling of the vehicle body can be realized, so that the passive safety of side impact of the vehicle body is improved.

According to the control method of the steering, anti-tilting and driving integrated wheel-side electric driving system, when the steering linear motor fails, the dual-rotor motor and the on-off of the clutch are controlled to realize the redundancy of steer-by-wire, so that the reliable steering safety is ensured.

Although embodiments of the present invention have been disclosed above, it is not limited to the details and embodiments shown and described, it is well suited to various fields of use for which the invention would be readily apparent to those skilled in the art, and accordingly, the invention is not limited to the specific details and illustrations shown and described herein, without departing from the general concepts defined in the claims and their equivalents.

Claims

1. A steering, anti-roll and drive integrated wheel-side electric drive system, comprising:

when the first clutch is combined, the output end of the inner rotor generates a resistance moment for preventing the suspension from jumping up and down, so that anti-tilting is realized;

the L-shaped anti-tilting rod comprises a first section and a second section which are perpendicular to each other, and the second section can rotate around the first section; the first section is connected with the first clutch, and the second section is connected with a shock absorber;

the lower end of the anti-tilting connecting rod is hinged with the end part of the second section, and the upper end of the anti-tilting connecting rod is hinged with the shock absorber;

also included is a fail-safe mechanism comprising:

a nut connected to the second clutch driven end;

2. The integrated steering, anti-roll and drive wheel side electric drive system of claim 1 wherein the steering gear is hollow over the nut by a needle bearing.

3. The integrated steering, anti-roll and drive wheel side electric drive system of claim 1, wherein the drive end of the first clutch is connected to the extended end of the anti-roll gear and the driven end is connected to the first segment end of the L-shaped anti-roll bar.

4. The integrated steering, anti-roll and drive wheel side electric drive system of claim 3 wherein the anti-roll gear is hollow sleeved at the end of the first section of the L-shaped anti-roll bar by a needle bearing.

5. A control method of a steering, anti-tilting and driving integrated wheel-side electric driving system for controlling the steering, anti-tilting and driving integrated wheel-side electric driving system according to any one of claims 1 to 4, characterized by comprising the steps of:

when the linear motor fails and no steering signal is input, the second clutch is controlled to be closed, the inner rotor of the double-rotor motor outputs a locked torque which keeps static, the steering wheels are locked, and the linear running of the automobile is maintained;

when the system has no fault, the linear motor controls the steering of the automobile according to the steering requirement of a driver; the output section of the outer rotor of the double-rotor motor outputs torque to drive the vehicle to run or outputs electromagnetic braking torque to electrically brake the automobile to reduce the speed; the output end of the inner rotor of the double-rotor motor can generate a resistance moment for preventing the suspension from jumping up and down to realize anti-tilting.

6. The control method of a steering, anti-roll and drive integrated wheel side electric drive system according to claim 5, further comprising determining a road surface condition based on the running road surface mode switching signal, and controlling a suspension stiffness based on the road surface condition;