CN109795470B - Active vibration reduction method of power system based on engine instantaneous torque observer - Google Patents
Active vibration reduction method of power system based on engine instantaneous torque observer Download PDFInfo
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Abstract
The invention provides an active vibration reduction method of a power system based on an engine instantaneous torque observer, and belongs to the field of electronic control of engines, motors or hybrid power systems. The method comprises the steps that an engine runs according to a set working condition; under each working condition, the whole vehicle control unit acquires engine state parameters and control parameters to add sensor signals; the instantaneous torque observer of the engine estimates to obtain an instantaneous torque fluctuation signal of the engine according to the parameters and the signal and the crankshaft signal and sends the instantaneous torque fluctuation signal to the motor controller; the motor controller calculates a target harmonic torque, generates a control signal and sends the control signal to the motor; the motor generates corresponding harmonic torque according to the received control signal; the instantaneous torque of the engine and the harmonic torque generated by the motor act on the transmission shaft simultaneously, so that the vibration reduction of the power system is realized. According to the invention, no extra hardware is required to be installed on the power system, and the high-frequency harmonic torque is added on the motor to inhibit the vibration of the transmission system, so that the driving comfort of the vehicle is improved.
Description
Technical Field
The invention belongs to the field of electronic control of engines, motors or hybrid power systems, and particularly provides an active vibration reduction method of a power system based on an engine instantaneous torque observer.
Background
The engine starting process is a key factor affecting the comfort of the driving process. In particular, in a hybrid system, the high fuel consumption condition (usually low speed, small load) and idling of the engine are cancelled, and the electric machine enables a quick start of the engine. Therefore, there are frequent starts and stops of the engine during running of the hybrid vehicle. Therefore, reducing the vibration during starting is critical to ensuring the comfort of the hybrid vehicle. During starting, vibration of the engine mainly comes from two aspects, firstly, before the engine fires (the diesel engine fires oil injection, and the gasoline engine fires a spark plug), pure compression and inertia force can cause vibration of a shafting; second, sudden changes in torque caused by engine firing can also cause shafting vibrations. Similarly, during the variable load process of the engine, the change of the fuel injection quantity (diesel engine) or the combustible mixture charge (gasoline engine) can cause the gas acting force of each cylinder of the engine to change, which can cause the fluctuation of the rotating speed of a shafting and threaten the driving comfort.
The existing vibration reduction method of the power system mainly solves the vibration problem in the starting process by designing an optimal starting rotating speed curve. The method comprises the steps of firstly carrying out dynamic modeling on an engine and a starting motor system, and researching the shafting vibration characteristic in the engine dragging process. And then extracting indexes capable of representing the vibration level, such as rotation nonuniformity coefficients, and designing an optimal starting speed curve of the engine through an optimization algorithm to enable the vibration indexes to be optimal. And finally, the motor is dragged to start the engine along the optimal starting rotating speed curve through the closed-loop control of the optimal starting rotating speed so as to verify the effectiveness of the algorithm. However, this method requires a complex physical model to be established, and the optimization result is only to achieve the optimum vibration index, and it is difficult to eliminate the vibration caused by the gas in the cylinder of the compression engine during the back-dragging. Moreover, after the engine is ignited, the electric machine is usually not involved any more, and it is difficult to deal with the vibration caused by the abrupt change of the combustion torque. In conventional engine power systems, the energy of the vibrations may also be attenuated by the installation of a flywheel and/or a torsional damper. Still other approaches limit the maximum rate of pressure rise within the cylinder by varying control parameters in dynamic processes, such as injection timing and exhaust gas recirculation rate, to achieve smooth starts or varying loads. Although the method for solving the vibration in the starting and variable load processes can reduce the vibration to a certain extent and improve the comfort in the driving process, the method does not solve the essential problem of rotating speed fluctuation caused by seizing, namely torque fluctuation in the working process of the engine. In a hybrid system, an engine is mechanically coupled with an electric machine, and the quick response speed of the electric machine provides possibility for reducing the rotation speed fluctuation of the engine during operation, especially a dynamic process, through active intervention of the electric machine.
The engine control system adopts a torque-based control system, namely, the torque demand of the engine is obtained by looking up a table according to the position of an accelerator pedal of a driver and the rotating speed of the engine. Other control parameters are derived from a lookup table based on the torque demand and the speed of the engine. The torque demand is the average torque of the engine, not the fluctuation of the instantaneous torque of the engine. Meanwhile, the average torque does not solve the high frequency problem of the hybrid system, such as vibration.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides an active vibration reduction method of a power system based on an engine instantaneous torque observer. According to the invention, no extra hardware is required to be installed on the power system, the instantaneous torque fluctuation of the engine is estimated through the instantaneous torque observer of the engine, the motor control unit MCU adds high-frequency harmonic torque to the motor by processing the instantaneous torque fluctuation estimated by the torque observer, so that the vibration of the transmission system is inhibited, and the comfort of the vehicle in the driving process is improved.
The invention provides an active vibration reduction method of a power system based on an engine instantaneous torque observer, which is characterized by comprising the following steps of:
1) the engine is controlled by the engine control unit to operate according to a set working condition;
2) under each working condition, the whole vehicle control unit acquires the state parameters, the control parameters and the additional sensor signals of the engine;
3) the instantaneous torque observer of the engine receives the engine state parameters, the control parameters, the additional sensor signals and the crankshaft signals obtained by the measurement of the encoder arranged at the output end of the crankshaft, which are collected in the step 2), estimates the instantaneous torque fluctuation of the engine, obtains the instantaneous torque fluctuation signals of the engine and sends the instantaneous torque fluctuation signals to the motor controller;
4) the motor controller calculates to obtain a target harmonic torque through an engine instantaneous torque fluctuation signal, generates a corresponding control signal and sends the corresponding control signal to the motor;
5) the motor generates corresponding harmonic torque according to the received control signal;
6) the instantaneous torque of the engine and the harmonic torque generated by the motor act on the transmission shaft simultaneously, so that the vibration reduction of the power system is realized.
The invention has the characteristics and beneficial effects that:
1) according to the invention, additional hardware is not required to be added, the instantaneous torque observer of the engine can estimate the instantaneous torque fluctuation of the engine, and the accurate response of the motor to the torque change of the engine is ensured.
2) The MCU adds high-frequency harmonic torque to the motor by processing the instantaneous torque fluctuation estimated by the torque observer, and the harmonic torque and the engine instantaneous torque fluctuation act on the transmission system together to realize the reduction of vibration in a high control frequency domain.
3) The active vibration reduction of the transmission system is realized through the estimation of the instantaneous torque fluctuation and the high-frequency control of the motor, and the active vibration reduction device can be used for more engine application scenes and has high practical value.
Drawings
FIG. 1 is an overall flow diagram of the method of the present invention.
FIG. 2 is a schematic diagram of the implementation effect of the method of the present invention.
Detailed Description
The invention provides an active vibration reduction method of a power system based on an engine instantaneous torque observer, which is further described in detail below by combining the accompanying drawings and specific embodiments.
The invention provides an active vibration reduction method of a power system based on an engine instantaneous torque observer, the overall flow is shown in figure 1, and the method comprises the following steps:
1) the engine is controlled by an ECU (engine control unit) to operate according to a set working condition (in the invention, the set working condition can be any working condition, including starting, stopping, accelerating, decelerating and the like, and the application scene is not limited).
2) In each working condition, a VCU (vehicle control unit) collects state parameters (air intake and cooling parameters), control parameters (oil injection and exhaust gas recirculation rate parameters) and additional sensor signals (in the embodiment, the additional sensor is a cylinder pressure sensor installed in each cylinder of the engine, and the cylinder pressure sensor collects in-cylinder pressure signals; in actual practice, sensor types may be added as desired).
3) And (3) receiving the engine state parameters, the control parameters, the additional sensor signals and crankshaft signals obtained by measurement of an encoder arranged at the output end of the crankshaft (the encoder is used for obtaining the position of the crankshaft, each electric control engine is provided with the encoder without additional installation), estimating the instantaneous torque fluctuation of the engine, obtaining the instantaneous torque fluctuation signals of the engine and sending the instantaneous torque fluctuation signals to the motor controller MCU (microprogrammed control Unit).
4) The MCU calculates a target harmonic torque capable of realizing shafting vibration reduction through an engine instantaneous torque fluctuation signal, generates a corresponding control signal and sends the control signal to the motor.
5) The motor generates corresponding harmonic torque according to the received control signal;
6) instantaneous torque of the engine and harmonic torque generated by the motor act on the transmission shaft simultaneously, and the fluctuation of output torque of the two power sources is counteracted mutually, so that the fluctuation of the rotating speed of the engine is reduced, the smoothness of a power system is improved, and vibration reduction of the power system is realized.
The engine, motor and ECU of the present invention may all employ conventional components. To achieve high frequency applications, the CAN (Controller Area Network) transmission rate of VCUs and MCUs should be in the order of 1 ms.
Said step 3) performs an estimation of the instantaneous torque fluctuations of the engine, for each cylinder of the engine, the following formula can be adopted:
wherein r is the radius of the crank,
the crank angle is β, the link swing angle is β, the ratio of crank to link is r/l, the central distance between big and small ends of link is l, the diameter of cylinder is D, and pgIs the absolute pressure of the gas in the cylinder, pbIs the absolute pressure of the crankcase gas, IcrankFor equivalent rotation of crankshaftAmount of the compound (A). Connecting rod pivot angle
The friction torque of the engine is related to the position of the crankshaft and the instantaneous rotating speed of the crankshaft and can be obtained by an empirical formula or an experimental means; m ishzIs the piston mass, mlAThe equivalent mass of the small end of the connecting rod, and omega is the rotating speed of the crankshaft;
the target harmonic torque of the step 4) can be calculated by adopting the following method, and for the n-cylinder engine:
wherein M ist_iRepresenting an estimate of the engine's instantaneous torque ripple for the i-th cylinder of the engine, and n is the number of cylinders of the engine. The effect of the method of the invention is shown in figure 2. In fig. 2, the torque ripple of the engine during a typical start is shown. The dotted grey line in the figure is the rotation speed fluctuation of the transmission system in the traditional loading process, and the solid black line is the rotation speed fluctuation after the method of the invention is adopted. A typical engine starting process involves two parts, namely, pre-ignition and post-ignition of the engine. Before the engine is ignited (for diesel engine, oil is injected, and for gasoline engine, ignition is performed by spark plugs), the motor drives the engine to accelerate. In the compression stroke, the piston compresses the working medium in the cylinder, in the expansion stroke, the working medium in the cylinder pushes the piston to do work, and the change of the torque in the pure compression process can cause the fluctuation of the rotating speed in the starting process. After the engine is ignited, the fuel is combusted to release heat, so that the pressure in the cylinder is increased suddenly, and the piston is pushed to output combustion torque outwards. Therefore, the transient of the engine ignition causes a sudden change in torque, and the torque fluctuation range is significantly increased. It can be seen that by adopting the method, the rotation speed fluctuation of the transmission system is obviously reduced, and the smoothness is improved.
The figures and the resulting examples of the above embodiments are intended only to illustrate the method and steps for reducing engine start-up process vibrations by adding motor harmonic torque. It should be noted that the start-up process in the figures is only one typical application scenario for dynamic processes, which should include, but are not limited to, engine start-up, shut-down, load shifting, and transmission. In addition, the traditional power system or hybrid power configuration, the structure, model, connection mode and manufacturing process of each component and the algorithm adopted by each module can be changed, and the equivalent transformation and improvement on the basis of the technical scheme of the invention are not excluded from the protection scope of the invention.
Claims (3)
1. An active vibration reduction method of a power system based on an engine instantaneous torque observer is characterized by comprising the following steps:
1) the engine is controlled by the engine control unit to operate according to a set working condition;
2) under each working condition, the whole vehicle control unit acquires the state parameters, the control parameters and the additional sensor signals of the engine;
3) the instantaneous torque observer of the engine receives the engine state parameters, the control parameters, the additional sensor signals and the crankshaft signals obtained by the measurement of the encoder arranged at the output end of the crankshaft, which are collected in the step 2), estimates the instantaneous torque fluctuation of the engine, obtains the instantaneous torque fluctuation signals of the engine and sends the instantaneous torque fluctuation signals to the motor controller; the estimation of the instantaneous torque fluctuation of the engine is carried out by the following expression:
wherein r is the radius of the crank,
the crank angle is β, the link swing angle is β, the ratio of crank to link is r/l, the central distance between big and small ends of link is l, the diameter of cylinder is D, and pgIs the absolute pressure of the gas in the cylinder, pbIs the absolute pressure of the crankcase gas, IcrankEquivalent moment of inertia for the crankshaft; connecting rod pivot angle
Is the friction torque of the engine; m ishzIs the piston mass, mlAThe equivalent mass of the small end of the connecting rod, and omega is the rotating speed of the crankshaft;
4) the motor controller calculates to obtain a target harmonic torque through an engine instantaneous torque fluctuation signal, generates a corresponding control signal and sends the corresponding control signal to the motor;
5) the motor generates corresponding harmonic torque according to the received control signal;
6) the instantaneous torque of the engine and the harmonic torque generated by the motor act on the transmission shaft simultaneously, so that the vibration reduction of the power system is realized.
2. The method of claim 1, wherein the additional sensor signal is an in-cylinder pressure signal obtained by installing a cylinder pressure sensor in each cylinder of the engine.
3. The method of claim 1, wherein the target harmonic torque in step 4) is calculated by the expression:
wherein M ist_iRepresenting an estimate of the engine's instantaneous torque ripple for the i-th cylinder of the engine, and n is the number of cylinders of the engine.
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| CN110863912B (en) * | 2019-10-11 | 2020-12-18 | 清华大学 | Engine cylinder deactivation method utilizing active vibration reduction |
| CN113353053B (en) * | 2021-06-23 | 2023-10-03 | 精进电动科技股份有限公司 | Hybrid power system and method for obtaining crank angle of engine in system |
| CN113859216B (en) * | 2021-10-28 | 2023-04-11 | 北京交通大学 | Hybrid power system multi-working-condition active vibration reduction control method based on vibration reduction waveform |
| CN114151216B (en) * | 2021-10-29 | 2022-08-12 | 清华大学 | Active vibration damping control method and device based on cylinder pressure reconstruction |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2468597A1 (en) * | 2010-12-21 | 2012-06-27 | Saab Automobile AB | Adaptation of a force-to-torque-characteristic for a launch clutch |
| CN104268304A (en) * | 2014-07-31 | 2015-01-07 | 中国第一汽车股份有限公司无锡油泵油嘴研究所 | engine instantaneous oil consumption determining method based on cylinder pressure |
| CN104295388A (en) * | 2014-08-14 | 2015-01-21 | 吉林大学 | Engine all-cylinder nonuniformity compensation control method based on indicated torque |
| CN105035079A (en) * | 2015-07-29 | 2015-11-11 | 江苏大学 | Power switching coordination control method of coaxial parallel hybrid electric vehicle with engine torque observer |
| CN107310399A (en) * | 2016-04-27 | 2017-11-03 | 通用汽车环球科技运作有限责任公司 | Method and apparatus for the vibration decay in power assembly system |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP4515439B2 (en) * | 2006-12-04 | 2010-07-28 | 本田技研工業株式会社 | Control device for hybrid vehicle |
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2468597A1 (en) * | 2010-12-21 | 2012-06-27 | Saab Automobile AB | Adaptation of a force-to-torque-characteristic for a launch clutch |
| CN104268304A (en) * | 2014-07-31 | 2015-01-07 | 中国第一汽车股份有限公司无锡油泵油嘴研究所 | engine instantaneous oil consumption determining method based on cylinder pressure |
| CN104295388A (en) * | 2014-08-14 | 2015-01-21 | 吉林大学 | Engine all-cylinder nonuniformity compensation control method based on indicated torque |
| CN105035079A (en) * | 2015-07-29 | 2015-11-11 | 江苏大学 | Power switching coordination control method of coaxial parallel hybrid electric vehicle with engine torque observer |
| CN107310399A (en) * | 2016-04-27 | 2017-11-03 | 通用汽车环球科技运作有限责任公司 | Method and apparatus for the vibration decay in power assembly system |
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