Method for improving comfort of vehicle passing through speed bump, motor controller and vehicle

Abstract

The invention discloses a method for improving comfort of a vehicle passing through a deceleration strip, a motor controller and the vehicle, relates to the field of new energy automobiles, and can be applied to pure electric vehicles and hybrid vehicles. The method is used for adjusting the output torque of a driving motor to improve the driving comfort in the process that the electric vehicle passes through the deceleration strip, and comprises the step of correspondingly adjusting the output torque of the driving motor corresponding to wheels according to the change of the opening degree of an accelerator pedal before the first moment when the wheels of the electric vehicle make contact with the deceleration strip. And after the second moment when the wheels leave the ground after passing through the deceleration strip, before the third moment when the wheels fall to the ground, and before the opening degree of the accelerator pedal is changed, the output torque of the driving motor corresponding to the wheels is actively reduced. And after the third moment, the output torque of the driving motor corresponding to the wheels is actively increased before the opening degree of the accelerator pedal is changed. According to the scheme, the road surface change is quickly sensed, the torque of the driving motor is quickly adjusted, and the safety and comfort of the vehicle are improved.

Description

Technical Field

[0001] The present application relates to the field of electric vehicles, and more particularly, to a method for improving the comfort of a vehicle passing through a speed bump, a motor controller and a vehicle. Background Art

[0002] With the development of the vehicle industry, the number of vehicles has increased year by year, and the comfort of electric vehicles has gradually become an important indicator of vehicles. For general consumers, especially passengers, comfort is very important. The main scenarios considered for long-term steady-speed driving conditions of electric vehicles include long-term driving on flat roads such as expressways such as highways and elevated roads, and sporadic driving on bumpy roads such as bridgeheads and potholes caused by road damage. These scenarios pose challenges to the electric drive and vehicle control systems in terms of power output characteristics, noise, vibration and acoustic vibration harshness (NVH) issues.

[0003] The current mainstream solution is based on fixed driving mode settings, and the vehicle is tuned to the corresponding drive, suspension and steering characteristics in a specific mode to meet different customer needs. For example, setting normal mode, sports mode and comfort mode, etc. Such a solution can meet customer needs in specific scenarios, but it cannot take into account automatic adjustment in different scenarios. For example, the comfort mode can better meet the driving conditions on flat roads, but in the scene of bumpy roads, it will cause problems such as tires flying off the ground.

[0004] Therefore, how to improve the comfort of electric vehicles when passing through speed bumps is a problem that needs to be solved. Summary of the invention

[0005] The present application provides a method, a motor controller and a vehicle for improving the comfort of a vehicle passing over speed bumps. During driving, for short-term bumpy road conditions, the method quickly senses road surface changes and quickly adjusts the drive motor torque when the vehicle contacts the road surface and experiences bumps, thereby preventing large fluctuations in wheel speed and improving the safety and comfort of the vehicle.

[0006] In the first aspect, the present application provides a method for improving the comfort of an electric vehicle passing through a speed bump, the method is used to adjust the output torque of a drive motor to improve the driving comfort during the process of the electric vehicle passing through the speed bump, and the method includes adjusting the torque output by the drive motor corresponding to the wheel according to the change in the opening of the accelerator pedal before the first moment when the wheel of the electric vehicle contacts the speed bump. After the second moment when the wheel leaves the ground after passing through the speed bump and before the third moment when the wheel lands, the output torque of the drive motor corresponding to the wheel is actively reduced before the opening of the accelerator pedal changes. After the third moment, the output torque of the drive motor corresponding to the wheel is actively increased before the opening of the accelerator pedal changes.

[0007] The electric vehicle can be an electric vehicle or a hybrid vehicle. The electric vehicle can be a distributed drive motor or a centralized drive motor architecture, with multiple drive motors and multiple motor controllers. The drive motor can be a wheel-side motor or a wheel hub motor, and the drive motor can independently drive one wheel of the vehicle.

[0008] The accelerator pedal in this application may also be referred to as an accelerator pedal or a gas pedal. The opening of the accelerator pedal can indicate the size of the driving force required by the driver. The larger the opening of the accelerator pedal, the greater the driver's demand for driving, and the corresponding torque required to be output by the drive motor is also greater. The motor controller can control the drive motor to output the torque indicated by the opening of the accelerator pedal according to the opening of the accelerator pedal. The larger the opening of the accelerator pedal, the greater the torque output by the drive motor. When the opening of the accelerator pedal is smaller, the torque output by the drive motor is smaller. The motor controller controls the torque output by the drive motor to change with the opening of the accelerator pedal. In this application, adjusting the torque output by the drive motor corresponding to the wheel according to the change of the opening of the accelerator pedal can refer to controlling the drive motor to output the torque indicated by the opening of the accelerator pedal. When the opening of the accelerator pedal changes, the torque output by the drive motor is controlled to change with the opening of the accelerator pedal.

[0009] When an electric vehicle is driving on a flat road, the torque output by the drive motor corresponding to the wheel is adjusted accordingly according to the change in the opening of the accelerator pedal. Before the first moment, the electric vehicle is driving on a flat road, and the drive motor of the electric vehicle is controlled to output the torque indicated by the opening of the accelerator pedal. At the first moment, the wheel of the electric vehicle contacts the speed bump, and the electric vehicle drives on a bumpy road. The wheel of the electric vehicle contacts the speed bump, the load torque of the wheel increases, the wheel and the suspension are compressed, the electric vehicle continues to drive, and the wheel and suspension compression are released, causing the wheel to jump off the ground at the second moment. After the second moment when the wheel leaves the ground after the wheel passes the speed bump and before the third moment when the wheel lands, because the wheel is suspended from the ground, the road surface loses adhesion to the road surface, the adhesion coefficient of the wheel decreases sharply, and the load torque of the wheel changes suddenly. If the output torque of the drive motor remains unchanged, the speed of the drive motor will change suddenly at this time, and then the wheel lands at the third moment, the load torque of the wheel is restored, and the speed of the drive motor changes drastically again, which will cause a great impact on the wheel and the suspension, and will also cause the vehicle to be greatly frustrated, causing discomfort to the driver and passengers. The technical solution provided in the embodiment of the present application will actively reduce the output torque of the drive motor corresponding to the wheel between the second moment and the third moment, before the opening of the accelerator pedal changes. In this way, after the wheel jumps off the ground, the output torque of the drive motor decreases rapidly, thereby suppressing the large fluctuation of the drive motor speed. The impact and setback of the electric vehicle when the wheel lands at the third moment will be alleviated, thereby reducing the impact and damage to the vehicle during the deceleration process, and improving the driving comfort of the driver and passengers.

[0010] It should be understood that the method is also used to adjust the output torque of the drive motor to improve driving comfort when the electric vehicle passes through other bumpy roads. Before the first moment when the wheel of the electric vehicle contacts a road surface with an unevenness greater than a preset unevenness, the torque output by the drive motor corresponding to the wheel is adjusted accordingly according to the change in the opening of the accelerator pedal. After the second moment when the wheel leaves the ground after the wheel passes through a road surface with an unevenness greater than the preset unevenness and before the third moment when the wheel lands, the output torque of the drive motor corresponding to the wheel is actively reduced before the opening of the accelerator pedal changes. After the third moment, the output torque of the drive motor corresponding to the wheel is actively increased before the opening of the accelerator pedal changes.

[0011] The bumpy road surface that the wheels of an electric vehicle contact may be, for example, a speed bump, a road bump, or a road pothole. When the wheels of an electric vehicle contact a bumpy road surface, the wheels may leave the ground, the wheel adhesion coefficient may change, and the load torque of the drive motor may suddenly change, which may cause a sudden change in the speed of the drive motor, which may cause damage to the hardware of the electric vehicle. The sudden change in wheel speed may also cause a sudden change in the speed of the electric vehicle, causing sudden acceleration or deceleration, resulting in discomfort to the driver and passengers. The preset roughness may be pre-calibrated based on actual vehicle experiments and / or model calculations, or it may be pre-set based on comprehensive consideration of vehicle requirements and vehicle performance.

[0012] It should be understood that the torque output by the drive motor can also be a negative value. The drive motor includes a stator winding and a rotor. By outputting alternating current to the three-phase stator winding, the output torque of the drive motor can be controlled. By adjusting the magnitude of the stator winding current and the phase of the three-phase current through the motor controller, the stator magnetic field strength and direction can be changed, thereby changing the interaction force between the stator and the rotor, that is, the motor torque. By changing the phase of the three-phase current output to the motor, the rotor cuts the magnetic field generated by the stator winding, and the kinetic energy of the rotor is converted into electrical energy and input into the power battery. At this time, the motor outputs a negative torque. By changing the magnitude of the three-phase current output to the motor by the motor controller, the positive torque or negative torque output by the motor can be increased or decreased. When the output torque of the drive motor is a negative value, the wheel receives a reverse torque, and the torque output by the drive motor is used to brake the wheel.

[0013] It should be understood that electric vehicles have driving conditions and feedback conditions during driving. Under the driving condition, the electric vehicle drive motor outputs positive torque to drive the wheels. After the second moment and before the third moment, the load torque of the drive motor changes suddenly, which will cause the speed of the drive motor to increase suddenly and significantly. At this time, it is necessary to actively control the drive motor to reduce the positive torque output. Under the feedback condition, the electric vehicle drive motor outputs negative torque to brake the wheels. After the second moment and before the third moment, the load torque of the drive motor changes suddenly, which will cause the speed of the drive motor to decrease suddenly and significantly. At this time, it is necessary to actively control the drive motor to reduce the negative torque output. Reducing the negative torque can be understood as reducing the absolute value of the negative torque, that is, increasing the negative value of the torque.

[0014] According to the solution of the present application, during driving, for short-term bumpy road conditions, the torque output by the drive motor can be quickly adjusted by quickly sensing road surface changes to prevent large fluctuations in wheel speed, thereby improving the safety and comfort of the vehicle.

[0015] In combination with the first aspect, in certain implementations of the first aspect, the method further includes adjusting the torque output by the drive motor accordingly according to a change in the opening of the accelerator pedal after actively increasing the output torque of the drive motor.

[0016] After the third moment, the wheels land and the electric vehicle returns to a flat road. Before the opening of the accelerator pedal changes, the drive motor is actively controlled to increase the torque output so that the drive torque output by the drive motor increases to a torque equal to the torque indicated by the opening of the accelerator pedal, thereby restoring the driving force of the electric vehicle. After the third moment, the drive motor is controlled to output the torque indicated by the opening of the accelerator pedal. When the opening of the accelerator pedal changes, the torque output by the drive motor is controlled to change with the opening of the accelerator pedal.

[0017] According to the solution of the present application, when the electric vehicle passes over a bumpy road and the wheels land on the ground, the drive motor is re-controlled to increase the torque to the torque indicated by the opening of the accelerator pedal, and the torque changes with the opening, thereby improving the vehicle's power and comfort.

[0018] In combination with the first aspect, in certain implementations of the first aspect, the method also includes actively controlling the torque output by the drive motor to reduce when the speed of the drive motor indicated by the rotary sensor of the drive motor suddenly changes between the second moment and the third moment, and the sudden change in the speed of the drive motor refers to an increase rate of the speed of the drive motor being greater than a preset value.

[0019] The rotary sensor can accurately detect the position, direction and speed of the motor rotor, and is responsible for monitoring and extracting the rotation speed of the drive motor. It has a high sampling rate and is directly connected to the motor controller 40, so the signal transmission time is short and the stability is higher. The rotation speed of the drive motor can be obtained by the rotary signal of the rotary sensor. The load torque of the drive motor can be calculated by the speed of the drive motor. After the second moment when the wheel leaves the ground and before the third moment when the wheel lands, the speed of the drive motor will change suddenly. Therefore, the load observation of the speed of the drive motor can be used to perceive whether there is a trend of extreme conditions on the road surface.

[0020] After the second moment when the wheel leaves the ground and before the third moment when the wheel lands, the change value of the drive motor speed indicated by the rotary sensor within a preset time period is greater than a preset value, and / or the load torque of the wheel is less than a first preset load, and / or the change value of the load torque of the wheel within a preset time period is greater than a preset load, and the torque output by the drive motor is actively controlled to decrease.

[0021] According to the solution of the present application, the rotation speed of the driving motor is detected by the rotary transformer signal, the changes in road conditions are quickly sensed and responded to quickly, which can effectively improve the speed and efficiency of detecting changes in the road surface contact of the electric vehicle.

[0022] In combination with the first aspect, in certain implementations of the first aspect, the method further includes controlling a suspension system of the electric vehicle to increase damping of a shock absorber of the suspension system between the second moment and the third moment.

[0023] The suspension system is used to connect the body of the electric vehicle with the wheels, and provides support, cushioning and stability during the driving of the electric vehicle. The suspension system may include shock absorbers. Each wheel may be connected to the body of the electric vehicle through a shock absorber. For a suspension system with adjustable damping shock absorbers, a target damping coefficient or a target damping level may be sent to the suspension system to adjust the damping of each shock absorber.

[0024] Between the second moment and the third moment, the wheels of the electric vehicle are off the ground because they pass over the speed bump, and the suspension system will absorb the impact of the road. If the damping of the shock absorber is small, there may be a problem of severe bumps. Therefore, it is necessary to increase the damping of the shock absorber, increase the hardness of the shock absorber, reduce the displacement of the tire relative to the body, and ensure the contact between the tire and the road.

[0025] According to the application plan, for short-term bumpy road conditions during driving, the damping of the shock absorber is increased, safety is given priority, the contact between the tire and the road is ensured, and the safety and comfort of the vehicle are improved.

[0026] In combination with the first aspect, in certain implementations of the first aspect, the method specifically includes that between the second moment and the third moment, the greater the speed of the electric vehicle, the greater the damping increase of the shock absorber is controlled.

[0027] When an electric vehicle encounters a speed bump or other bumpy road surface during driving, the greater the speed of the electric vehicle, the greater the impact that needs to be absorbed. Therefore, adjusting the wheels to a larger target damping will provide more sufficient support.

[0028] According to the solution of the present application, the shock absorber damping is determined according to the speed of the electric vehicle, the stability control function of the suspension system is fully utilized, the vehicle stability control is quickly achieved, and the vehicle safety and comfort are improved.

[0029] In combination with the first aspect, in certain implementations of the first aspect, the method further includes, at a fourth moment after the third moment, controlling a suspension system of the electric vehicle to reduce damping of the shock absorber.

[0030] At the third moment, the wheels of the electric vehicle land on the ground and re-enter the flat road. Since the wheels have just touched the ground, the body of the electric vehicle is still moving due to the buffering effect of the suspension system. If the shock absorber damping is small at this time, the body of the electric vehicle will move up and down with a large amplitude. At this time, the shock absorber damping should be maintained at a large level. For a period of time after the third moment, the shock absorber damping of the suspension system is maintained at a large level. During this period of time, the body movement of the electric vehicle tends to be stable. At a fourth moment after a period of time from the third moment, the suspension system is controlled to reduce the damping of the shock absorber.

[0031] It should be understood that the duration from the third moment to the fourth moment may be pre-calibrated based on actual vehicle experiments and / or model calculations, or may be pre-set based on comprehensive consideration of vehicle requirements and vehicle performance.

[0032] According to the solution of the present application, when the electric vehicle travels over a bumpy road, the suspension system maintains a large damping for a period of time, and after the body of the electric vehicle stabilizes, the damping of the shock absorber of the suspension system is reduced.

[0033] In combination with the first aspect, in certain implementations of the first aspect, the method further includes controlling the steering system to reduce the steering assist strength of the steering wheel of the electric vehicle and increase the steering feedback strength of the steering wheel between the second moment and the third moment.

[0034] The steering assist strength refers to the amount of assist provided when the steering wheel is turned. Steering assist is a technology that assists the driver in adjusting the direction of the car, which can reduce the driver's steering effort. When the driver turns the steering wheel, the steering system can generate assist force, thereby helping the driver to easily complete the steering action.

[0035] The force feedback of the vehicle steering system can provide the driver with real-time road feel feedback by providing steering wheel resistance torque. Reducing the steering feedback force of the steering wheel can reduce the driver's road feel and filter out road bumps. Increasing the steering feedback force of the steering wheel can enhance the driver's road feel and improve the driver's controllability.

[0036] Between the second moment and the third moment, the wheels of the electric vehicle leave the ground, the resistance of the road suddenly decreases, the road feel of the steering wheel of the electric vehicle decreases, and the driver will feel that the steering wheel suddenly becomes lighter. If the driver controls the steering wheel with the same force as when driving on a flat road, the steering wheel angle will increase. In order to ensure the safety of the electric vehicle, the steering assist strength of the steering wheel of the electric vehicle is actively reduced and the steering feedback strength of the steering wheel is increased, thereby improving the controllability of the electric vehicle.

[0037] According to the solution of the present application, when the electric vehicle encounters bumps, safety is prioritized, the force feedback of the steering system is enhanced, the steering assist is actively reduced, the driver's road feel is enhanced, and the safety and controllability of the electric vehicle are improved.

[0038] In combination with the first aspect, in certain implementations of the first aspect, the control method further includes, after the third moment, controlling the steering system to increase the steering assist strength of the steering wheel of the electric vehicle and reduce the steering feedback strength of the steering wheel.

[0039] After the third moment, the wheels of the electric vehicle land on the ground, and the electric vehicle re-enters the flat road. At this time, the steering system is controlled to restore the comfort parameters, and the steering system is controlled to increase the steering assist strength of the steering wheel of the electric vehicle and reduce the steering feedback strength of the steering wheel.

[0040] According to the solution of the present application, when the electric vehicle travels over a bumpy road, the comfort parameters of the steering system are restored, the steering assist strength of the steering wheel of the electric vehicle is increased and the steering feedback strength of the steering wheel is reduced, thereby improving the comfort of the electric vehicle.

[0041] In combination with the first aspect, in certain implementations of the first aspect, the control method further includes, after the third moment, actively controlling the steering system of the electric vehicle to adjust the steering angles of the two rear wheels so that the electric vehicle travels in the direction indicated by the steering wheel.

[0042] The steering system of an electric vehicle can control the steering of the rear wheels. The steering system can change the turning angle and direction of the two rear wheels, so that the electric vehicle can effectively adjust the steering and handling characteristics of the vehicle through different steering methods. At low speeds, when the steering direction of the rear wheels is opposite to that of the front wheels, the turning radius can be reduced, improving the overall handling and flexibility of the vehicle. At high speeds, when the steering direction of the rear wheels is the same as that of the front wheels, the vehicle yaw moment generated by the steering operation can be effectively reduced, enhancing the stability of the vehicle.

[0043] After the third moment, the wheels of the electric vehicle landed, and the electric vehicle re-entered a flat road. Since the electric vehicle had just passed a bumpy road, the electric vehicle may have extreme situations such as jumping and throwing. When the electric vehicle landed, the direction may be offset. The driving direction of the electric vehicle is different from the angle indicated by the steering wheel angle. In order to make the electric vehicle drive under control again, the two rear wheels of the electric vehicle are controlled to steer, and the steering angle of the two rear wheels is the same as the direction in which the electric vehicle deviated, so that the electric vehicle drives in the direction indicated by the steering wheel.

[0044] At the third moment, the electric vehicle state including the change of yaw angular velocity and center of mass sideslip angle can be combined to detect whether the electric vehicle is running off the track. The electric vehicle's driving direction deviates from the angle indicated by the steering wheel angle, including the electric vehicle's yaw acceleration being greater than a preset acceleration or the electric vehicle's center of mass sideslip angle being greater than a preset angle.

[0045] It should be understood that, at the third moment, the greater the speed of the electric vehicle, the smaller the steering angle of the two rear wheels adjusted by the steering system controlling the electric vehicle.

[0046] The faster the vehicle speed, the greater the impact of the rear wheel steering angle on the vehicle posture and trajectory. At this time, the yaw control torque applied through the steering will be greater, and the danger will be greater. The higher the speed, the greater the risk of loss of control. Therefore, the higher the speed, the smaller the steering angle of the rear wheels controlled by the steering system.

[0047] According to the solution of the present application, when an electric vehicle passes over a bumpy road, if the driving direction of the electric vehicle deviates, active intervention and correction are carried out to adjust the steering angle of the rear wheels according to different driving conditions of the vehicle to ensure that the vehicle does not deviate, reduce the risk of vehicle loss of control, and improve the safety of the electric vehicle.

[0048] In combination with the first aspect, in some implementations of the first aspect, the method further includes that from a fifth moment after the third moment to a sixth moment after the fifth moment, the increase in the accelerator pedal opening of the electric vehicle is less than a preset value, and the increase in the torque output by the drive motor is controlled to be zero. From a seventh moment after the third moment to an eighth moment after the seventh moment, the increase in the accelerator pedal opening of the electric vehicle is greater than a preset value, and the torque output by the drive motor is controlled to increase.

[0049] When a small change in the opening of the accelerator pedal causes the indicated torque to change repeatedly, if the drive motor always responds to the change in the opening of the accelerator pedal, it will cause the driver and passengers to feel uncomfortable with repeated acceleration and deceleration. When the electric vehicle is driving on a flat road, in order to ensure the comfort of the driver and passengers, the drive motor of the electric vehicle may not respond to small changes in the opening of the accelerator pedal.

[0050] From the fifth moment to the sixth moment, the change in the accelerator pedal opening is less than the preset difference, that is, the accelerator pedal opening changes to a small opening, and at this time, the increase in the torque output by the control drive motor is zero.

[0051] From the seventh moment to the eighth moment, the change in the accelerator pedal opening is greater than the preset difference, that is, the accelerator pedal opening changes to a large opening, reflecting the driver's true acceleration intention. At this time, the torque output by the control drive motor increases.

[0052] According to the solution of the present application, small opening changes of the accelerator pedal are filtered, and the drive motor does not respond to repeated torque changes caused by small opening changes of the accelerator pedal, thereby reducing the discomfort of repeated acceleration and deceleration and improving the comfort of the electric vehicle.

[0053] In combination with the first aspect, in certain implementations of the first aspect, the method further includes, after the third moment, when the accelerator pedal opening of the electric vehicle is less than a first preset opening, controlling the force feedback of the accelerator pedal of the electric vehicle to increase.

[0054] When the opening of the accelerator pedal of the electric vehicle is less than the first preset opening, the accelerator pedal of the electric vehicle is at a low opening, and the speed of the electric vehicle is low. If the force feedback of the accelerator pedal is small, the driver is likely to step on the accelerator pedal, resulting in a rapid change in the opening, a large acceleration of the electric vehicle, and discomfort to the driver and passengers. Therefore, the force feedback of the accelerator pedal of the electric vehicle can be increased so that the driver can effectively control the acceleration amplitude.

[0055] According to the solution of the present application, the force feedback at a low opening of the accelerator pedal is enhanced, thereby effectively improving the safety and controllability of the electric vehicle.

[0056] In combination with the first aspect, in certain implementations of the first aspect, the control method further includes, after the third moment, controlling the change value of the torque output by the drive motor within a preset time period to always be less than a preset torque.

[0057] When an electric vehicle is traveling on a flat road, the driving torque can be filtered, and the acceleration and acceleration rate of the vehicle can be controlled based on comfort. The target torque can be compensated through real-time jerk observation to prevent rapid changes in torque.

[0058] According to the solution of the present application, the torque change rate of the drive motor output is controlled to be not too large, thereby avoiding the discomfort of sudden acceleration and deceleration of the electric vehicle and improving the comfort of the electric vehicle.

[0059] In the second aspect, the present application provides a motor controller, which is used to improve the comfort of an electric vehicle when passing through a speed bump. The motor controller is used to adjust the torque output by the drive motor corresponding to the wheel according to the change in the opening of the accelerator pedal before the first moment when the wheel of the electric vehicle contacts the speed bump. After the second moment when the wheel leaves the ground after passing through the speed bump and before the third moment when the wheel lands, the output torque of the drive motor corresponding to the wheel is actively reduced before the opening of the accelerator pedal changes. After the third moment, the output torque of the drive motor corresponding to the wheel is actively increased before the opening of the accelerator pedal changes.

[0060] The motor controller is suitable for electric vehicles or hybrid vehicles. The electric vehicle can be a distributed motor or a centralized motor architecture with multiple drive motors and multiple motor controllers. The motor controller can be any one of the multiple motor controllers.

[0061] In conjunction with the second aspect, in certain implementations of the second aspect, the motor controller is further configured to send a tire lift-off mark signal to a suspension system of the electric vehicle between the second moment and the third moment, the tire lift-off mark signal being configured to indicate that a wheel has lifted off a road surface. The tire lift-off mark signal is configured to instruct the suspension system to control the suspension system of the electric vehicle to increase the damping of a shock absorber of the suspension system.

[0062] In conjunction with the second aspect, in certain implementations of the second aspect, the motor controller is further configured to send a tire lift-off mark signal to a steering system of the electric vehicle between the second moment and the third moment, the tire lift-off mark signal being configured to indicate that the wheel has lifted off the road surface. The tire lift-off mark signal is configured to instruct the steering system to reduce the steering assist strength of the steering wheel and increase the steering feedback strength of the steering wheel.

[0063] In a third aspect, the present application provides an electric vehicle, which includes a motor controller as described in the second aspect. The motor controller is used to receive power from a power battery and drive a drive motor to rotate.

[0064] In combination with the third aspect, in certain implementations of the third aspect, the electric vehicle includes a suspension system and a steering system. The suspension system is used to control the suspension system of the electric vehicle to increase the damping of the shock absorber of the suspension system in response to the tire lift-off mark signal. The steering system is used to reduce the steering assist strength of the steering wheel and increase the steering feedback strength of the steering wheel in response to the tire lift-off mark signal.

[0065] The beneficial effects of other aspects can refer to the beneficial effects described in the first aspect and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 is a schematic diagram of a scene in which an electric vehicle provided in an embodiment of the present application drives over a bumpy road;

[0067] Figure 2 is a schematic diagram of an electric vehicle provided in an embodiment of the present application;

[0068] Figure 3 is a schematic diagram of the architecture of an electric vehicle provided in an embodiment of the present application;

[0069] Figure 4 This is a schematic diagram of a comfortable driving control process of an electric vehicle provided in an embodiment of the present application;

[0070] Figure 5 is another schematic diagram of a comfortable driving control process for an electric vehicle provided in an embodiment of the present application;

[0071] Figure 6 is a schematic diagram of a process of an electric vehicle passing over a speed bump provided by an embodiment of the present application;

[0072] Figure 7 is a schematic diagram of a process of an electric vehicle driving through a pothole provided by an embodiment of the present application;

[0073] Figure 8 is another schematic diagram of a comfortable driving control process for an electric vehicle provided in an embodiment of the present application;

[0074] Fig. 9 is a schematic diagram of the motor controller architecture provided by an embodiment of the present application;

[0075] Fig.10 It is a schematic diagram of signal interaction for improving driving comfort control provided in an embodiment of the present application. DETAILED DESCRIPTION

[0076] The following will describe the technical solution in the present application in conjunction with the accompanying drawings. The detailed description of the following embodiments and the accompanying drawings are used to exemplarily illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0077] For passengers, comfort is one of the key indicators of long-term steady-speed driving. The scenarios include long-term flat road driving and sporadic bumpy road driving. Long-term flat road driving requires adjustment of the drive system and vehicle control system to control power output to eliminate or alleviate motion sickness. At the same time, sporadic bumpy road driving requires consideration of comfort while ensuring driving safety. For example, when an electric vehicle is driving on a road such as Figure 1 The road surface shown in (a) or Figure 1 When the road surface is potholed as shown in (b), there will be safety issues such as the tire flying off the ground. Often the driver will not adjust the driving mode during driving, or will not have time to adjust the driving mode to cope with short-term sudden working conditions. Multiple working conditions cannot be taken into account. Even in manual mode, the gear options for adjustment are limited, and the adjustment parameter settings are cognitive challenges for general users.

[0078] Based on the above problems, the present application provides a method, a motor controller and a vehicle for improving the comfort of a vehicle passing through speed bumps. During driving, for short-term bumpy road conditions, the method can quickly sense road surface changes and quickly detect the occurrence of vehicle contact with road bumps, and quickly adjust the drive motor torque to prevent large fluctuations in wheel speed, thereby improving the safety and comfort of the vehicle.

[0079] Figure 2 and Figure 3 It is a schematic diagram of the architecture of the electric vehicle 10 provided in an embodiment of the present application.

[0080] like Figure 2 As shown, the electric vehicle 10 includes a vehicle controller 20, a drive motor 30, a motor controller 40, a suspension system 50, a steering system 60, a power battery (not shown) and a plurality of wheels. The motor controller 40 is used to output current to the drive motor 30 to control the drive motor 30 to output torque to drive the electric vehicle 10.

[0081] Among them, the electric vehicle 10 includes but is not limited to pure electric vehicle (pure electric vehicle / battery electric vehicle, pure EV / battery EV), hybrid electric vehicle (hybrid electric vehicle, HEV), range extended electric vehicle (range extended electric vehicle, REEV), plug-in hybrid electric vehicle (plug-in hybrid electric vehicle, PHEV), new energy vehicle (new energy vehicle, NEV), etc.

[0082] In one embodiment, the electric vehicle 10 is a distributed four-drive motor drive architecture, and the drive motor is arranged on the side of the driven wheel and controlled by a separate motor controller 40. In one embodiment, the electric vehicle is also a centralized drive motor drive architecture, and the drive motors for driving two front wheels or two rear wheels are arranged together. There are one or more motor controllers 40. The motor controller 40 corresponds to the drive motor one-to-one, or one motor controller 40 corresponds to multiple drive motors. The motor controller 40 is used to control the output torque of one or more drive motors to drive the electric vehicle 10.

[0083] In one embodiment, if Figure 3 As shown in (a) of FIG. 1 , the electric vehicle 10 is a distributed four-drive motor drive architecture, where the drive motors are arranged on the sides of the driven wheels and are controlled by a separate motor controller. Figure 3 The centralized four-drive motor drive architecture shown in (b) is configured such that two drive motors for driving two front wheels or two rear wheels are arranged together.

[0084] Exemplarily, the electric vehicle 10 includes four motor controllers, including a motor controller 41, a motor controller 42, a motor controller 43, and a motor controller 44. The four motors include a drive motor 31, a drive motor 31, a drive motor 33, and a drive motor 34. The motor controller 41 controls the drive motor 31 to drive the wheel 51, the motor controller 42 controls the drive motor 32 to drive the wheel 52, the motor controller 43 controls the drive motor 33 to drive the wheel 53, and the motor controller 44 controls the drive motor 34 to drive the wheel 54.

[0085] In one embodiment, the electric vehicle 10 is also Figure 3 The centralized drive motor architecture shown in (c) uses one drive motor to drive the two front wheels of the electric vehicle 10, and uses two drive motors to drive the two rear wheels of the electric vehicle 10 respectively.

[0086] In one embodiment, the various architectures mentioned above may be combined, for example, the front drive adopts a distributed drive motor architecture and the rear drive adopts a centralized drive motor architecture.

[0087] The motor controller 40 provided in the present application is any one of a plurality of motor controllers.

[0088] The electric vehicle 10 further includes an accelerator pedal and a steering wheel. The accelerator pedal is used to indicate the torque output to the wheels of the electric vehicle 10. The turning angle of the steering wheel is used to indicate the steering angle of the two front wheels.

[0089] In one embodiment, the motor controller 40 includes a signal interface, and the motor controller 40 is connected to the vehicle controller 20 and other motor controllers 40 through the signal interface. The vehicle controller 20 is connected to the accelerator pedal signal, and the vehicle controller 20 calculates the vehicle torque demand according to the opening of the accelerator pedal during the driving process of the electric vehicle 10, and sends a torque signal to the motor controller 40 according to the vehicle torque demand. Each motor controller 40 controls the corresponding drive motor to output torque to drive the corresponding wheel according to the indication of the torque signal.

[0090] In one embodiment, each motor controller 40 is directly connected to an accelerator pedal, and controls the output torque of the corresponding drive motor according to a torque signal output by the accelerator pedal.

[0091] In one embodiment, each motor controller 40 uses a resolver sensor through a signal interface, and the resolver sensor is used to detect the speed of the drive motor 30 controlled by the motor controller 40. The motor controller 40 is used to receive the signal from the resolver sensor. The motor controller 40 generates a speed signal according to the signal from the resolver sensor and sends the speed signal to the other three motor controllers 40. Similarly, each motor controller 40 also receives the speed signal sent by the other three motor controllers 40.

[0092] The resolver sensor can accurately detect the position, direction and speed of the motor rotor, and is responsible for monitoring and extracting the rotation speed of the drive motor. It has a high sampling rate and is directly connected to the motor controller 40, with short signal transmission time and higher stability.

[0093] In one embodiment, the motor controller 40 also obtains vehicle signals from the vehicle controller 20 or other sensors of the electric vehicle 10 through a signal interface, and the vehicle signals are used to indicate the speed, yaw rate, and sideslip angle of the center of mass of the electric vehicle 10 .

[0094] In one embodiment, the electric vehicle 10 further includes a suspension system 50, which is used to connect the body and wheels of the electric vehicle 10 and provide support, buffering and stability during the driving of the electric vehicle 10. The suspension system 50 includes a shock absorber. Each wheel is individually connected to the body of the electric vehicle through a shock absorber.

[0095] In one embodiment, the suspension system 50 of the electric vehicle 10 includes a variable damping shock absorber. The variable damping shock absorber is a shock absorber that adjusts the damping force by an electronic control method according to the vehicle driving conditions, for example, by changing the flow resistance of the fluid inside the shock absorber to adjust the damping force, thereby achieving a change in the response characteristics of the suspension system. A target damping coefficient or a target damping level is sent to the suspension system 50 to adjust the damping of each shock absorber.

[0096] In one embodiment, the suspension system 50 of the electric vehicle 10 includes an air spring. The suspension system 50 adjusts the vehicle height by inflation and deflation, thereby providing a comfortable ride and good handling performance.

[0097] In one embodiment, the electric vehicle 10 also includes a steering system 60, which is used to control the two rear wheels of the electric vehicle 10 to adjust the steering angle. The steering system 60 changes the turning angle and direction of the two rear wheels, thereby effectively adjusting the steering and handling characteristics of the vehicle through different steering methods. When the vehicle speed is low, when the steering direction of the rear wheels is opposite to the steering direction of the front wheels, the turning radius is reduced, and the overall handling and flexibility of the vehicle are improved. When the vehicle speed is high, when the steering direction of the rear wheels is the same as the steering direction of the front wheels, the vehicle yaw moment generated by the steering operation is effectively reduced, and the driving stability of the vehicle is enhanced. The steering system 60 changes the turning angle and direction of the two rear wheels to give the vehicle a higher control margin, which can improve the handling and flexibility of the vehicle at low speeds, while enhancing the stability at high speeds and reducing the risk of vehicle loss of control.

[0098] In one embodiment, the motor controller 40 is connected to the vehicle controller 20, the suspension system 50 and the steering system 60 via a controller area network (CAN) bus, a local interconnect network (LIN) bus, a high-speed fault-tolerant network protocol (FlexRay) or other types of connection methods, and exchanges signals.

[0099] The control method provided in the embodiment of the present application is used to control the drive motor of the electric vehicle to reduce the torque output when the electric vehicle 10 encounters a bumpy road surface while driving on a flat road, thereby preventing sudden changes in the drive motor speed and wheel speed fluctuations from causing discomfort to the driver and passengers. The change in the road surface is sensed by the drive motor speed, and the drive system parameters are actively adjusted according to the change in the road surface. There is no need for the driver to manually switch modes or adjust driving parameters, thereby effectively improving the comfort and safety of the electric vehicle.

[0100] Combine the following Figure 4 , Figure 5 , Figure 6 and Figure 7 The method and motor controller 40 for improving the comfort of an electric vehicle passing through a speed bump provided in an embodiment of the present application are described at the first moment t1, the second moment t2, the third moment t3, the fourth moment t4, the fifth moment t5, the sixth moment t6, the seventh moment t7 and the eighth moment t8 during the driving process of the electric vehicle 10. Figure 4 and Figure 5 is a signal timing diagram of the electric vehicle 10 during driving, Figure 4 This includes the relationship between the accelerator pedal opening of the electric vehicle and the drive motor speed, drive motor output torque, suspension damping, steering assist strength, steering force feedback strength, and rear wheel steering angle during the driving of the electric vehicle. Figure 5 The relationship between the opening degree of the accelerator pedal of the electric vehicle and the output torque of the drive motor is included in the process of the electric vehicle driving.

[0101] Figure 4 and Figure 6 The process of the wheels of the electric vehicle 10 passing through the speed bump is described. Figure 6 The process of the front wheels of the electric vehicle 10 passing through the speed bump is shown in FIG. The process of the rear wheels of the electric vehicle 10 passing through the speed bump is the same as that of the front wheels. Figure 4 and Figure 6 , the first moment t1 is the moment when the wheel of the electric vehicle 10 contacts the speed bump, the second moment t2 is the moment when the wheel leaves the ground after passing through the speed bump, and the third moment t3 is the moment when the wheel falls to the ground after passing through the speed bump. The fourth moment t4 is the moment after the electric vehicle 10 has been driving on a flat road for a period of time. The electric vehicle 10 first drives on a flat road, and the driver keeps the opening of the accelerator pedal unchanged. At the first moment t1, the wheel of the electric vehicle 10 contacts the speed bump. At the second moment t2, due to the inertia of the electric vehicle 10, the wheel leaves the ground. At the third moment t3, the wheel of the electric vehicle 10 falls to the ground, and the shock absorber of the suspension system 50 of the electric vehicle 10 absorbs the impact of the vehicle body falling to the ground. At the fourth moment t4, the electric vehicle 10 tends to be stable on the flat road.

[0102] In one embodiment, see Figure 4 and Figure 6 Before the first moment t1 when the wheel of the electric vehicle 10 contacts the speed bump, the torque output by the drive motor 30 corresponding to the wheel is adjusted accordingly according to the change in the opening degree of the accelerator pedal.

[0103] Before the first time t1 , the electric vehicle 10 is traveling on a flat road, and at this time, the motor controller 40 controls the driving motor 30 of the electric vehicle 10 to output a torque indicated by the opening degree of the accelerator pedal.

[0104] At the first time t1 , the wheels of the electric vehicle 10 contact the speed bump, and the electric vehicle 10 travels on a bumpy road.

[0105] In one embodiment, after the second moment t2 when the wheel leaves the ground after passing through the speed bump and before the third moment t3 when the wheel lands, the output torque of the drive motor 30 corresponding to the wheel is actively reduced before the opening of the accelerator pedal changes.

[0106] After the second moment t2 when the wheel leaves the ground after passing through the speed bump and before the third moment t3 when the wheel lands, because the wheel is suspended from the ground, the road surface loses adhesion to the road surface, the adhesion coefficient of the wheel decreases sharply, and the load torque of the wheel changes suddenly. If the output torque of the drive motor 30 remains unchanged, the speed of the drive motor 30 will change suddenly at this time. Then at the third moment t3, the wheel lands, the load torque of the wheel is restored, and the speed of the drive motor 30 changes drastically again, which will cause a great impact on the wheel and the suspension, and will also cause a large setback in the vehicle, causing discomfort to the driver and passengers. The technical solution provided in the embodiment of the present application will actively reduce the output torque of the drive motor 30 corresponding to the wheel between the second moment t2 and the third moment t3, before the opening of the accelerator pedal changes. In this way, after the wheel jumps off the ground, the output torque of the drive motor 30 decreases rapidly, thereby suppressing the large fluctuation of the speed of the drive motor 30. The impact on the electric vehicle 10 and the setback of the vehicle when the wheel lands at the third moment t3 will be alleviated, thereby reducing the impact and damage to the vehicle during the deceleration process of the vehicle, and also improving the driving comfort of the driver and passengers.

[0107] In the embodiment of the present application, the electric vehicle 10 has a driving condition and a feedback condition during driving. Under the driving condition, the drive motor 30 of the electric vehicle 10 outputs positive torque to drive the wheel. After the second moment t2 when the wheel leaves the ground after passing through the speed bump and before the third moment t3 when the wheel lands, the wheel of the electric vehicle 10 leaves the ground, and the load torque of the drive motor 30 suddenly changes, which will cause the speed of the drive motor 30 to suddenly increase significantly. At this time, it is necessary to actively control the drive motor 30 to reduce the positive torque output. Under the feedback condition, the drive motor 30 of the electric vehicle 10 outputs negative torque to brake the wheel. After the second moment t2 when the wheel leaves the ground after passing through the speed bump and before the third moment t3 when the wheel lands, the wheel of the electric vehicle 10 leaves the ground, and the load torque of the drive motor 30 suddenly changes, which will cause the speed of the drive motor 30 to suddenly decrease significantly. At this time, it is necessary to actively control the drive motor 30 to reduce the negative torque output. Reducing the negative torque is understood as reducing the absolute value of the negative torque.

[0108] In one embodiment, between the second moment t2 and the third moment t3, the speed of the drive motor 30 indicated by the rotary sensor of the drive motor 30 suddenly changes, and the torque output by the drive motor 30 is actively controlled to decrease. The sudden change in the speed of the drive motor 30 means that the increase rate of the speed of the drive motor 30 is greater than a preset value.

[0109] The rotary sensor accurately detects the position, direction and speed of the rotor of the drive motor 30, is responsible for monitoring and extracting the rotation speed of the drive motor 30, has a high sampling rate, and is directly connected to the motor controller 40, with a short signal transmission time and higher stability. The rotation speed of the drive motor 30 is obtained by the rotary signal of the rotary sensor. The load torque of the drive motor is calculated by the rotation speed of the drive motor 30. After the second moment t2 when the wheel leaves the ground and before the third moment t3 when the wheel lands, the rotation speed of the drive motor 30 will change suddenly, so the load observation of the rotation speed of the drive motor 30 is used to perceive whether there is a trend of extreme conditions on the road surface.

[0110] When the increase rate of the rotation speed of the drive motor 30 is greater than a preset value, the motor controller 40 determines that the wheels of the electric vehicle 10 are in contact with a bumpy road surface, and the internal closed loop of the electric controller 40 actively controls the torque output by the drive motor 30 to decrease. At this time, the torque output by the drive motor 30 controlled by the motor controller 40 is not equal to the torque indicated by the accelerator pedal opening.

[0111] In another implementation, after the second moment t2 when the wheel leaves the ground and before the third moment t3 when the wheel lands, the change value of the drive motor speed indicated by the rotary sensor within a preset time length is greater than a preset value, and / or the load torque of the wheel is less than a first preset load, and / or the change value of the load torque of the wheel within a preset time length is greater than a preset load, and the motor controller 40 actively controls the torque output by the drive motor 30 to decrease.

[0112] According to the embodiments provided in the present application, the rotational speed of the drive motor is detected by means of a rotary transformer signal, changes in road conditions are quickly sensed and responded to, thereby effectively improving the speed and efficiency of detecting changes in the road surface contact of the electric vehicle, quickly adjusting the torque output by the drive motor, preventing large fluctuations in wheel speed, and improving the safety and comfort of the vehicle.

[0113] In one embodiment, after the third moment t3, the output torque of the drive motor 30 corresponding to the wheel is actively increased before the opening of the accelerator pedal changes. After the output torque of the drive motor 30 is actively increased, the torque output by the drive motor 30 is adjusted accordingly according to the change in the opening of the accelerator pedal.

[0114] After the third moment t3, the wheels land and the electric vehicle 10 returns to a flat road. Before the opening of the accelerator pedal changes, the drive motor 30 is actively controlled to increase the torque output so that the drive torque output by the drive motor 30 increases to a torque equal to the torque indicated by the opening of the accelerator pedal, thereby restoring the driving force of the electric vehicle 10. After the third moment t3, the drive motor 30 is controlled to output the torque indicated by the opening of the accelerator pedal. When the opening of the accelerator pedal changes, the torque output by the drive motor 30 is controlled to change with the opening of the accelerator pedal.

[0115] In one embodiment, after the third moment t3, when the accelerator pedal opening of the electric vehicle 10 is less than the first preset opening, the force feedback of the accelerator pedal of the electric vehicle 10 is controlled to increase.

[0116] When the accelerator pedal opening of the electric vehicle 10 is less than the first preset opening, the accelerator pedal of the electric vehicle 10 is at a low opening, and the speed of the electric vehicle 10 is low. If the force feedback of the accelerator pedal is small, the driver is likely to step on the accelerator pedal, resulting in a rapid change in the opening, and the acceleration of the electric vehicle 10 is large, making the driver and passengers feel uncomfortable. Therefore, the force feedback of the accelerator pedal of the electric vehicle 10 is increased, so that the driver can effectively control the acceleration amplitude.

[0117] In a possible embodiment, by adjusting the comfort setting of the accelerator pedal Pedal Map, it is ensured that the accelerator pedal opening is at a comfortable position for the driver's pedal foot during constant speed driving at medium or high vehicle speeds.

[0118] In one embodiment, see Figure 5From the fifth moment t5 after the third moment t3 to the sixth moment t6 after the fifth moment t5, the increase in the accelerator pedal opening of the electric vehicle 10 is less than the preset value, and the increase in the torque output by the control drive motor 30 is zero. From the seventh moment t7 after the third moment t3 to the eighth moment t8 after the seventh moment t7, the increase in the accelerator pedal opening of the electric vehicle 10 is greater than the preset value, and the torque output by the control drive motor 30 increases.

[0119] When a small change in the opening of the accelerator pedal causes the indicated torque to change repeatedly, if the drive motor 30 always responds to the change in the opening of the accelerator pedal, it will cause the driver and passengers to feel uncomfortable with repeated acceleration and deceleration. When the electric vehicle 10 is traveling on a flat road, in order to ensure the comfort of the driver and passengers, the drive motor 30 of the electric vehicle 10 does not respond to a small change in the opening of the accelerator pedal.

[0120] From the fifth moment t5 to the sixth moment t6, the change in the accelerator pedal opening is less than the preset difference, that is, the accelerator pedal opening changes to a small opening, and at this time, the increase in the torque output by the drive motor 30 is controlled to be zero.

[0121] From the seventh moment t7 to the eighth moment t8, the change in the accelerator pedal opening is greater than the preset difference, that is, the accelerator pedal opening changes to a large opening, reflecting the driver's true acceleration intention. At this time, the torque output by the control drive motor 30 increases.

[0122] By applying software torque filtering processing, it is ensured that when the electric vehicle 10 is in steady speed control, the alternating positive and negative torque caused by small changes in the pedal opening will not cause the passengers to feel uncomfortable due to repeated small acceleration and deceleration of the vehicle. By filtering the smaller torque changes, 0Nm is used to achieve the driver's purpose of slowing down the vehicle, so as to avoid tossing the throttle back and forth, and at the same time will not affect the actual acceleration and deceleration intention.

[0123] By filtering small opening changes of the accelerator pedal, the drive motor 30 does not respond to repeated torque changes caused by small opening changes of the accelerator pedal, thereby reducing the discomfort of repeated acceleration and deceleration and improving the comfort of the electric vehicle 10.

[0124] In one embodiment, between the second time t2 and the third time t3 , the suspension system 50 of the electric vehicle 10 is controlled to increase the damping of the shock absorber of the suspension system 50 .

[0125] The suspension system 50 is used to connect the body and wheels of the electric vehicle 10, and provide support, buffering and stability during the driving of the electric vehicle 10. The suspension system 50 includes a shock absorber. Each wheel is connected to the body of the electric vehicle 10 through a shock absorber. For the suspension system 50 with adjustable damping shock absorbers, a target damping coefficient or a target damping level is sent to the suspension system 50, so as to adjust the damping of each shock absorber.

[0126] Between the second moment t2 and the third moment t3, the wheels of the electric vehicle 10 pass over the speed bump. Due to the inertia of the electric vehicle 10, the wheels will leave the ground. When the wheels fall from the height above the ground to the ground, the suspension system 50 carries the vehicle body downward and absorbs the energy of the electric vehicle 10. Since the shock absorber of the suspension system 50 is elastic, the shock absorber will rebound after being compressed. If the damping of the shock absorber of the suspension system 50 is small, the stroke of the shock absorber being compressed will be larger, and the stroke of the rebound will also be larger, which may cause the body of the electric vehicle 10 to bump up and down violently, making the driver and passengers feel uncomfortable. Therefore, it is necessary to control the suspension system 50 to increase the damping of the shock absorber and improve the hardness of the shock absorber, so that after the shock absorber absorbs the impact, the compression and rebound strokes of the shock absorber are shorter, which reduces the displacement of the tire relative to the body and ensures the contact between the tire and the road surface.

[0127] In one embodiment, between the second time t2 and the third time t3, the greater the speed of the electric vehicle 10 is, the greater the damping increase of the shock absorber is controlled.

[0128] When the electric vehicle 10 encounters a speed bump or other bumpy road surface during driving, the greater the speed of the electric vehicle 10, the greater the impact that needs to be absorbed may be. Therefore, adjusting the wheels to a larger target damping can provide more sufficient support force.

[0129] In one embodiment, between the second moment t2 and the third moment t3, the motor controller 40 is used to send a tire lift-off mark signal to the suspension system 50 of the electric vehicle 10, and the tire lift-off mark signal is used to indicate that the wheel has jumped off the road surface. The tire lift-off mark signal is used to instruct the suspension system 50 to control the suspension system 50 of the electric vehicle 10 to increase the damping of the shock absorber of the suspension system.

[0130] The suspension system 50 is used to control the suspension system 50 of the electric vehicle 10 to increase the damping of the shock absorber of the suspension system in response to the tire lift-off mark signal.

[0131] The motor controller 40 controls the suspension system 50 to timely adjust the damping of the shock absorber. The motor controller 40 detects the rotation speed of the drive motor 30 through the resolver signal, quickly senses changes in road conditions, and responds quickly, thereby improving the damping adjustment effect of the suspension system 50.

[0132] In one embodiment, at a fourth time t4 after the third time t3 , the suspension system 50 of the electric vehicle 10 is controlled to reduce the damping of the shock absorber.

[0133] At the third moment t3, the wheels of the electric vehicle 10 land and re-enter the flat road. Since the wheels have just touched the ground, the body of the electric vehicle 10 is still moving up and down due to the buffering effect of the suspension system 50. If the shock absorber damping is small at this time, the amplitude of the up and down movement of the body of the electric vehicle will be large. At this time, the shock absorber damping should still be maintained at a large level. For a period of time after the third moment t3, the shock absorber damping of the suspension system 50 is maintained at a large level. During this period of time, the body movement of the electric vehicle 10 tends to be stable. At the fourth moment t4, which is a period of time after the third moment t3, the suspension system 50 is controlled to reduce the damping of the shock absorber.

[0134] In one embodiment, between the second time t2 and the third time t3, the steering system 60 is controlled to reduce the steering assist strength of the steering wheel of the electric vehicle and increase the steering feedback strength of the steering wheel.

[0135] The steering assist strength refers to the magnitude of the assist provided when the steering wheel is turned. Steering assist is a technology that assists the driver in adjusting the direction of the car, reducing the driver's steering effort. When the driver turns the steering wheel, the steering system 60 generates assist force, thereby helping the driver to easily complete the steering action.

[0136] The force feedback of the vehicle steering system 60 provides the driver with road feeling feedback in real time by providing steering wheel resistance torque. Reducing the steering feedback force of the steering wheel reduces the driver's road feeling and filters the bumps on the road. Increasing the steering feedback force of the steering wheel enhances the driver's road feeling and improves the driver's controllability.

[0137] Between the second moment t2 and the third moment t3, the wheels of the electric vehicle 10 leave the ground, the resistance of the road surface suddenly decreases, the road feel of the steering wheel of the electric vehicle 10 decreases, and the driver will feel that the steering wheel suddenly becomes lighter. If the same force is maintained as when driving on a flat road, the steering wheel angle will increase. In order to ensure the safety of the electric vehicle 10, the steering assist strength of the steering wheel of the electric vehicle 10 is actively reduced and the steering feedback strength of the steering wheel is increased, thereby improving the controllability of the electric vehicle 10.

[0138] In one embodiment, between the second moment t2 and the third moment t3, the motor controller 40 is used to send a tire lift-off mark signal to the steering system 60 of the electric vehicle 10, and the tire lift-off mark signal is used to indicate that the wheel has jumped off the road surface. The tire lift-off mark signal is used to instruct the steering system 60 to reduce the steering assist strength of the steering wheel and increase the steering feedback strength of the steering wheel.

[0139] The steering system 60 is used for reducing the steering assist strength of the steering wheel and increasing the steering feedback strength of the steering wheel in response to the tire lift-off mark signal.

[0140] In one embodiment, after the third time t3 , the steering system 60 is controlled to increase the steering assist strength of the steering wheel of the electric vehicle 10 and reduce the steering feedback strength of the steering wheel.

[0141] After the third moment t3, the wheels of the electric vehicle 10 land on the ground, and the electric vehicle 10 re-enters the flat road. At this time, the steering system 60 is controlled to restore the comfort parameters, and the steering system 60 is controlled to increase the steering assist strength of the steering wheel of the electric vehicle 10 and reduce the steering feedback strength of the steering wheel, thereby improving the comfort of the electric vehicle.

[0142] In one embodiment, after the third moment t3, the steering system 60 of the electric vehicle 10 is actively controlled to adjust the steering angles of the two rear wheels so that the electric vehicle 10 travels in the direction indicated by the steering wheel.

[0143] The steering system 60 of the electric vehicle 10 controls the steering of the rear wheels. The steering system 60 changes the turning angle and direction of the two rear wheels, so that the electric vehicle 10 effectively adjusts the steering and handling characteristics of the vehicle through different steering methods. When the vehicle speed is low, when the steering direction of the rear wheels is opposite to the steering direction of the front wheels, the turning radius is reduced, and the overall handling and flexibility of the vehicle are improved. When the vehicle speed is high, when the steering direction of the rear wheels is the same as the steering direction of the front wheels, the vehicle yaw moment generated by the steering operation is effectively reduced, and the stability of the vehicle driving is enhanced.

[0144] After the third moment t3, the wheels of the electric vehicle 10 fall to the ground, and the electric vehicle 10 re-enters a flat road. Since the electric vehicle 10 has just passed a bumpy road, the electric vehicle 10 may be thrown or jumped, and when the electric vehicle 10 falls to the ground, the direction may be offset, and the driving direction of the electric vehicle 10 is different from the angle indicated by the steering wheel angle. In order to make the electric vehicle 10 drive under control again, the two rear wheels of the electric vehicle 10 are controlled to steer, and the steering angles of the two rear wheels are the same as the direction in which the electric vehicle 10 is offset, so that the electric vehicle 10 drives in the direction indicated by the steering wheel.

[0145] At the third moment t3, the electric vehicle 10 is detected to see whether it is running off the track in combination with the state of the electric vehicle 10, including the change of the yaw angular velocity and the sideslip angle of the center of mass. The direction of the electric vehicle 10 deviates from the angle indicated by the steering wheel angle, including when the yaw acceleration of the electric vehicle 10 is greater than the preset acceleration or the sideslip angle of the center of mass of the electric vehicle is greater than the preset angle.

[0146] It should be understood that at the third time t3, the greater the speed of the electric vehicle, the smaller the steering angle of the two rear wheels adjusted by the steering system 60 of the electric vehicle 10 is.

[0147] The faster the vehicle speed is, the greater the influence of the rear wheel steering angle on the vehicle posture and trajectory will be. At this time, the yaw control torque applied through the steering will be greater, and the danger will be greater. The higher the speed, the greater the risk of loss of control. Therefore, the higher the speed, the smaller the steering angle of the rear wheels controlled by the steering system 60 will be.

[0148] According to the solution of the present application, when an electric vehicle passes over a bumpy road, if the driving direction of the electric vehicle deviates, active intervention and correction are carried out to adjust the steering angle of the rear wheels according to different driving conditions of the vehicle to ensure that the vehicle does not deviate, reduce the risk of vehicle loss of control, and improve the safety of the electric vehicle.

[0149] It should be understood that the method provided in the embodiment of the present application is also applicable to adjusting the output torque of the drive motor 30 to improve driving comfort when the electric vehicle 10 passes through other bumpy roads.

[0150] The road surface with an unevenness greater than the preset unevenness that the wheels of the electric vehicle 10 contact is, for example, a speed bump, a road bump, or a road pothole. When the wheels of the electric vehicle 10 contact a road surface with an unevenness greater than the preset unevenness, the wheels may leave the ground, the adhesion coefficient of the wheels may change, and the load torque of the drive motor may suddenly change, which may cause a sudden change in the speed of the drive motor, which may cause damage to the hardware of the electric vehicle 10. The sudden change in wheel speed may also cause a sudden change in the speed of the electric vehicle, causing sudden acceleration or deceleration, resulting in discomfort to the driver and passengers. The preset unevenness is pre-calibrated based on actual vehicle experiments and / or model calculations, or is pre-set based on comprehensive consideration of vehicle requirements and vehicle performance.

[0151] For example, Figure 8 The process of the wheel of the electric vehicle 10 passing through the pit is described. Figure 8 The process of the front wheels of the electric vehicle 10 passing through a pothole is shown, and the process of the rear wheels of the electric vehicle 10 passing through a speed bump is the same as that of the front wheels.

[0152] In one embodiment, if Figure 4 and Figure 8As shown, the first moment t1 is the moment when the wheel of the electric vehicle 10 contacts the pothole, the second moment t2 is the moment when the wheel leaves the ground after passing through the pothole, and the third moment t3 is the moment when the wheel falls to the ground after passing through the pothole. The fourth moment t4 is the moment after the electric vehicle 10 has been driving on a flat road for a period of time. The electric vehicle 10 first drives on a flat road, and the driver keeps the opening of the accelerator pedal unchanged. At the first moment t1, the wheel of the electric vehicle 10 contacts the pothole. At the second moment t2, due to the inertia of the electric vehicle 10, the wheel leaves the ground. At the third moment t3, the wheel of the electric vehicle 10 falls to the ground, and the shock absorber of the suspension system 50 of the electric vehicle 10 absorbs the impact of the vehicle body falling to the ground. At the fourth moment t4, the electric vehicle 10 tends to be stable on a flat road. Please refer to the previous text for the specific control description, which will not be repeated here.

[0153] In one embodiment, the driver turns on or switches the driving mode of the electric vehicle 10 to the "comfort mode" by pressing a button or a central control, controls the suspension system 50 of the electric vehicle 10 to reduce the damping of the decelerator, and controls the steering system 60 of the electric vehicle 10 to increase the steering assist strength of the steering wheel and reduce the steering feedback strength of the steering wheel.

[0154] In one embodiment, the electric vehicle 10 is set with a separate "comfort mode". When the electric vehicle 10 enters the "comfort mode", the corresponding suspension system 50 and steering system 60 characteristics are adjusted to give priority to comfort, filter the road feel, and improve driving comfort.

[0155] It should be understood that the driver does not need to use a button or central control to turn on or switch the driving mode of the electric vehicle 10 to the "comfort mode". The electric vehicle 10 is in the "comfort mode" by default, or the basic parameters of the electric vehicle 10 prioritize comfort.

[0156] For the flat road driving condition, the suspension system 50 adjusts the damping strength according to the comfort priority, and the steering system 60 adjusts the steering assist strength according to the comfort priority, which can better meet the flat road driving condition.

[0157] In one embodiment, if Figure 8 As shown, the change value of the torque output by the control driving motor 30 within the preset time period is always smaller than the preset torque.

[0158] When the electric vehicle 10 is traveling on a flat road, the driving torque is filtered, and the acceleration and acceleration change rate of the whole vehicle are controlled with comfort as the guide, and the target torque is compensated through real-time jerk observation to prevent rapid changes in torque. The torque change rate output by the drive motor 30 is controlled not to be too large, thus avoiding the discomfort caused by rapid acceleration and deceleration of the electric vehicle 10 and improving the comfort of the electric vehicle 10.

[0159] According to the solution of this application, the vehicle can drive comfortably on a flat road, improve the linearity of the throttle, reduce the feeling of dizziness, and quickly adjust the characteristics of the drive, suspension and steering components when there are occasional bumpy roads, ensure the contact between the tire and the road, and improve safety. After the bumpy road passes, the adjustment is restored to the comfort priority.

[0160] Combine the following Fig. 9 and Fig.10 The control architecture of the motor controller 40 provided in the embodiment of the present application and the control signals for improving the comfort control are described.

[0161] The motor controller 40 acquires the resolver signal sent by the resolver sensor in real time, thereby obtaining the rotation speed of the drive motor 30 .

[0162] In one embodiment, the motor controller 40 also obtains an accelerator pedal opening signal, a steering wheel angle signal, an inertial sensor signal, and a wheel speed signal.

[0163] The load observation depending on the speed of the drive motor 30 is used to sense whether the road surface has an extreme situation such as a tendency to bounce or fall into a pit. If the extreme scene trend appears or the extreme scene is confirmed, the motor controller 40 sends a corresponding scene flag such as a tire off the ground flag. The flag is sent to the drive system, the suspension system 50 and the steering system 60 through a signal.

[0164] When the motor controller 40 sends a tire lift-off mark signal, the motor controller 40 controls the drive motor 30 to adjust the output torque.

[0165] After receiving the mark, the suspension system 50 will prioritize safety, increase the active damping coefficient, improve the shock absorber hardness, reduce the displacement of the tire relative to the vehicle body, and ensure the contact between the tire and the road surface. After the tire ground clearance mark is withdrawn, the suspension system 50 returns to the parameter setting that prioritizes comfort.

[0166] After receiving the tire lift-off mark signal, the steering system 60 will prioritize safety, enhance the force feedback of the steering system 60, actively reduce the steering assist, make the steering wheel heavier, and enhance the driver's road feel. After the tire lift-off mark signal is withdrawn, the steering system 60 returns to the parameter setting that prioritizes comfort.

[0167] In one embodiment, after receiving the tire lift-off mark signal, the steering system 60 will actively intervene and correct the vehicle based on the yaw rate and the sideslip angle of the center of mass in the vehicle state to ensure that the vehicle does not deviate.

[0168] Combination Figure 4As shown, in one embodiment, before the first moment t1, the torque output by the drive motor 30 corresponding to the wheel is adjusted accordingly according to the change in the opening of the accelerator pedal. At the second moment t2, the motor controller 40 calculates the road adhesion change according to the resolver signal of the resolver sensor, identifies that the wheel of the electric vehicle 10 contacts the speed bump, and sends the tire ground clearance mark to multiple systems and components. The tire ground clearance mark is used to indicate that the wheel jumps off the road. After the second moment t2 when the wheel leaves the ground after passing the speed bump and before the third moment t3 when the wheel lands, the motor controller 40 sends a torque signal to the drive system to actively control the drive motor 30 to reduce the torque output. The motor controller 40 sends the target damping to the suspension system 50 to control the suspension system of the electric vehicle 10 to increase the damping of the shock absorber. The motor controller 40 sends the steering mode to the steering system 60 to control the steering system to reduce the steering assist strength of the steering wheel of the electric vehicle 10 and increase the steering feedback strength of the steering wheel. After the third moment t3, the motor controller 40 withdraws the tire ground clearance mark, and the motor controller 40 actively increases the output torque of the drive motor 30 corresponding to the wheel before the opening of the accelerator pedal changes. The steering system 60 is controlled to increase the steering assist strength of the steering wheel of the electric vehicle and reduce the steering feedback strength of the steering wheel. In combination with the driving state of the electric vehicle 10, if the driving direction of the electric vehicle 10 deviates from the angle indicated by the steering wheel angle, the steering system 60 of the electric vehicle 10 is controlled to adjust the rotation of the two rear wheels in the driving direction of the electric vehicle. At the fourth moment t4, the motor controller 40 controls the suspension system 50 of the electric vehicle 10 to reduce the damping of the shock absorber.

[0169] According to the embodiment provided in the present application, the bumpy road surface and the response flag position are sensed by the driving motor speed, rapid sensing, rapid feedback control, and rapid adjustment of the driving motor torque to prevent large fluctuations in wheel speed, thereby improving the safety and comfort of the vehicle, shortening the characteristic adjustment time of the suspension and steering, and enhancing the comfort and safety on bumpy roads.

[0170] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for improving the comfort of an electric vehicle passing through a speed bump, characterized in that: The method is used to adjust the output torque of the driving motor to improve the driving comfort when the electric vehicle passes through the speed bump, and the method includes: Before the first moment when the wheel of the electric vehicle contacts the speed reduction belt, adjusting the torque output by the driving motor corresponding to the wheel accordingly according to the change of the opening degree of the accelerator pedal; After the second moment when the wheel leaves the ground after the wheel passes through the speed bump and before the third moment when the wheel lands, actively reducing the output torque of the drive motor corresponding to the wheel before the opening degree of the accelerator pedal changes; After the third moment, the output torque of the drive motor corresponding to the wheel is actively increased before the opening degree of the accelerator pedal changes.

2. The method according to claim 1, characterized in that The method further comprises: After the output torque of the driving motor is actively increased, the torque output by the driving motor is adjusted accordingly according to the change in the opening degree of the accelerator pedal.

3. The method according to claim 1, characterized in that The method further comprises: Between the second moment and the third moment, the rotational speed of the drive motor indicated by the rotary sensor of the drive motor changes suddenly, and the torque output by the drive motor is actively controlled to decrease. The sudden change in the rotational speed of the drive motor means that the increase rate of the rotational speed of the drive motor is greater than a preset value.

4. The method according to claim 1, characterized in that: The method further comprises: Between the second moment and the third moment, the suspension system of the electric vehicle is controlled to increase the damping of a shock absorber of the suspension system.

5. The method according to claim 4, characterized in that The method specifically comprises: Between the second moment and the third moment, the greater the vehicle speed of the electric vehicle is, the greater the damping increase amount of the shock absorber is controlled to be.

6. The method according to claim 4 or 5, characterized in that: The method further comprises: At a fourth time after the third time, the suspension system of the electric vehicle is controlled to reduce the damping of the shock absorber.

7. The method according to any one of claims 1 to 6, characterized in that The method further comprises: Between the second moment and the third moment, the steering system is controlled to reduce the steering assist strength of the steering wheel of the electric vehicle and increase the steering feedback strength of the steering wheel.

8. The method according to claim 7, characterized in that The method further comprises: After the third moment, the steering system is controlled to increase the steering assist strength of the steering wheel of the electric vehicle and to reduce the steering feedback strength of the steering wheel.

9. The method according to any one of claims 1 to 8, characterized in that The method further comprises: After the third moment, the steering system of the electric vehicle is actively controlled to adjust the steering angles of the two rear wheels so that the electric vehicle travels in the direction indicated by the steering wheel.

10. The method according to any one of claims 1 to 9, characterized in that The method further comprises: From a fifth moment after the third moment to a sixth moment after the fifth moment, the increase in the accelerator pedal opening of the electric vehicle is less than a preset value, and the increase in the torque output by the drive motor is controlled to be zero; From a seventh moment after the third moment to an eighth moment after the seventh moment, the increase value of the accelerator pedal opening of the electric vehicle is greater than a preset value, and the torque output by the drive motor is controlled to increase.

11. The method according to any one of claims 1 to 10, characterized in that The method further comprises: After the third moment, when the accelerator pedal opening of the electric vehicle is less than a first preset opening, the force feedback of the accelerator pedal of the electric vehicle is controlled to increase.

12. A motor controller, characterized in that: The motor controller is used to improve the comfort of the electric vehicle when passing through a speed bump. The motor controller is used to: Before the first moment when the wheel of the electric vehicle contacts the speed reduction belt, adjusting the torque output by the driving motor corresponding to the wheel accordingly according to the change of the opening degree of the accelerator pedal; After the second moment when the wheel leaves the ground after the wheel passes through the speed bump and before the third moment when the wheel lands, actively reducing the output torque of the drive motor corresponding to the wheel before the opening degree of the accelerator pedal changes; After the third moment, the output torque of the drive motor corresponding to the wheel is actively increased before the opening degree of the accelerator pedal changes.

13. The motor controller according to claim 12, characterized in that: The motor controller is also used for: Between the second moment and the third moment, sending a tire lift-off mark signal to a suspension system of the electric vehicle, wherein the tire lift-off mark signal is used to indicate that the wheel has lifted off the road surface; The tire lift-off mark signal is used to instruct the suspension system to control the suspension system of the electric vehicle to increase the damping of the shock absorber of the suspension system.

14. The motor controller according to claim 12, characterized in that: The motor controller is also used for: Between the second moment and the third moment, sending a tire lift-off mark signal to the steering system of the electric vehicle, wherein the tire lift-off mark signal is used to indicate that the wheel has lifted off the road surface; The tire lift-off mark signal is used to instruct the steering system to reduce the steering assist strength of the steering wheel and increase the steering feedback strength of the steering wheel.

15. A vehicle, characterized in that: The electric vehicle comprises a motor controller, a drive motor and a power battery as described in any one of claims 12 to 14, wherein the motor controller is used to receive power from the power battery and drive the drive motor to rotate.

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