CN117734452A - Self-adaptive ramp auxiliary control method and system for vehicle - Google Patents

Abstract

The invention relates to a self-adaptive ramp auxiliary control method and a self-adaptive ramp auxiliary control system for a vehicle, and belongs to the technical field of safety control of new energy vehicles; when the current vehicle working condition state meets the activation condition, the self-adaptive ramp auxiliary control function is activated, wherein the activation condition comprises that the vehicle is in a backward running state, and the activation condition also comprises that a brake signal is effective. The activation condition of the self-adaptive ramp auxiliary control function comprises that when a brake signal is effective but the vehicle is in a backward sliding state, when the vehicle has braking force output but the braking force is insufficient to support the vehicle to stay on a slope, the vehicle exits from a braking mode, the self-adaptive ramp auxiliary control function is activated, the self-adaptive ramp auxiliary control function timely outputs driving force to enable the vehicle to stay on the slope, and the situation that the braking force is insufficient to support the vehicle to stay on the slope during running braking is timely linked, so that the backward sliding distance of the vehicle during hill starting can be effectively reduced, the anti-sliding performance is improved, and the safety and the comfort of starting operation of a driver are improved.

Description

Self-adaptive ramp auxiliary control method and system for vehicle

Technical Field

The invention relates to a self-adaptive ramp auxiliary control method and a self-adaptive ramp auxiliary control system for a vehicle, and belongs to the technical field of safety control of new energy vehicles.

Background

At present, new energy vehicles are continuously developed, and the share of pure electric vehicles and range-extending hybrid electric vehicles in the automobile market is continuously expanded.

If the vehicle does not have the anti-slip locking mechanism, when the vehicle is in the ascending forward gear climbing starting mode or the descending reverse gear climbing starting mode, a certain time is needed from the release of the brake pedal to the stepping of the accelerator, if the driver is unskilled, the operation time is too long, and the vehicle is in danger of slipping downwards; when the vehicle is parked on a slope, the operation requirement on a driver is high, the vehicle is easy to slide, and the safety is poor. Due to the high cost of installing the gradient sensor, it is difficult to quickly and stably control the motor torque to achieve the purpose of stopping the vehicle on a slope without knowing the gradient.

In order to realize rapid hill-holding and anti-slip, the following method is generally adopted:

(1) the sensor is additionally arranged to acquire accurate gradient information, and the required driving torque is calculated according to the gradient information when the anti-slip function is activated, so that the cost of the mode is high; (2) the torque control PI regulation control method is used, the regulating time is long, the backward sliding distance is long, the anti-sliding performance is poor, and especially under the working condition of relatively large gradient, the safety is poor; (3) the zero rotation speed PI regulation control is realized only through the motor controller, and the method is easy to cause faults such as overlarge motor locked-rotor current, high motor system temperature and the like; (4) the activation of the adaptive ramp auxiliary control function is determined only by the backward running speed, and the method can possibly cause unexpected activation of the vehicle, so that the vehicle shakes during running, and the driving comfort is reduced.

The activation condition of the existing self-adaptive ramp auxiliary control function is based on the backward running rotating speed of the motor during backward running, if a driver mistakenly touches a brake pedal and the like, the self-adaptive ramp auxiliary control function cannot be activated, if the braking force of the vehicle on the ramp is insufficient to support the vehicle to reside on the slope at the moment, the vehicle still can backward run, the backward running distance is large when the vehicle starts, and the anti-slip performance is poor.

Based on the above, an adaptive hill assist control method and system for a vehicle is presented.

Disclosure of Invention

The invention aims to provide a self-adaptive ramp auxiliary control method and a system for a vehicle, which are used for solving the problem of poor anti-slip performance caused by the fact that the braking force is insufficient to support the vehicle to stay on a slope when the activation condition of the existing self-adaptive ramp auxiliary control function cannot be timely connected with service braking.

In order to achieve the above object, the present invention provides a method comprising:

according to the self-adaptive ramp auxiliary control method for the vehicle, when the current working condition of the vehicle meets the activation condition, the self-adaptive ramp auxiliary control function is activated, the activation condition comprises that the vehicle is in a backward sliding state, and the activation condition also comprises that a brake signal is effective.

The activation condition of the existing self-adaptive ramp auxiliary control function is that the vehicle is in a backward sliding state, and is different from the existing activation condition, the activation condition of the self-adaptive ramp auxiliary control function comprises that when a brake signal is effective but the vehicle is in a backward sliding state, when the vehicle has braking force output but the braking force is insufficient to support the vehicle to stay on a slope, the vehicle exits from a braking mode, the self-adaptive ramp auxiliary control function is activated, the self-adaptive ramp auxiliary control function timely outputs driving force to enable the vehicle to stay on the slope, and the self-adaptive ramp auxiliary control function timely engages with the condition that the braking force is insufficient to support the vehicle to stay on the slope when in service braking, so that the backward sliding distance of the vehicle during hill starting can be effectively reduced, the anti-sliding performance is improved, and the safety and the comfort of starting operation of a driver are improved.

Further, the rollback state is determined by: the motor rotation direction of the actual gear requirement of the vehicle is inconsistent with the motor actual rotation direction, and the vehicle speed exceeds a first set threshold value and does not exceed a set second threshold value.

The backward slip state is judged by the backward slip rotating speed, and is different from the judgment of the existing backward slip state, and the backward slip state is judged by the following modes: the motor rotation direction of the actual gear requirement of the vehicle is inconsistent with the actual rotation direction of the motor, meanwhile, the vehicle speed exceeds a first set threshold value and does not exceed a set second threshold value, the after-activation sliding speed range is reasonably set, the timely activation of the self-adaptive ramp auxiliary control function is guaranteed, the backward sliding distance of the vehicle is shortened, the non-activation of the anti-sliding ramp when the after-sliding speed is too large is guaranteed, the activation of the self-adaptive ramp auxiliary control function at the moment is avoided, the self-adaptive ramp auxiliary control function suddenly outputs larger braking force, and potential safety hazards exist. Furthermore, the backward slip of the larger vehicle speed can be perceived by the driver, when the vehicle should be handled properly in response, for example by a service brake.

Further, when the self-adaptive ramp auxiliary control function is activated, the whole vehicle controller obtains the feedforward torque for preventing the vehicle from sliding and transmits the feedforward torque to the motor controller, and the motor controller combines the feedforward torque and adopts a closed-loop zero-rotation speed control method to realize the anti-sliding control of the vehicle.

When the self-adaptive ramp auxiliary control function is activated, the whole vehicle controller and the motor controller are interactively and cooperatively controlled, so that the whole vehicle controller can acquire a large number of whole vehicle signals, judge the whole vehicle state and the self-adaptive ramp auxiliary control function activation condition more comprehensively and output feedforward torque; and the motor controller receives the activation time to control the vehicle to realize the purpose of fast hill-holding, so that the anti-slip performance is improved, and the convenience and safety of starting operation of a driver are improved. The motor control system is matched with the whole vehicle controller and the motor controller together, so that the faults of overlarge motor locked-rotor current, high motor system temperature and the like caused by the control of the motor controller are avoided.

Further, the backward slip speed before the adaptive ramp assist control function is activated exceeds a third set threshold, and the feedforward torque is output in fixed steps per cycle.

According to the invention, the third set threshold value set for the backward sliding speed is used as a determining factor that the feedforward torque is output in a fixed step length increasing mode per cycle, namely, when the backward sliding speed before the self-adaptive ramp auxiliary control function is activated exceeds the third set threshold value, the feedforward torque is output in a fixed step length increasing mode per cycle, the forward running of the vehicle caused by direct output of the feedforward torque is avoided, and the safety of starting operation of a driver is effectively improved. The third setting threshold can be obtained according to off-line calibration.

Specifically, the third set threshold is greater than the first set threshold and less than the second set threshold. More specifically, the third set threshold value should be set to a value close to the second set threshold value according to off-line calibration, and at this time, the feedforward torque is output in a fixed step length increased every cycle, so that the situation that the vehicle is forward-flushed to a greater extent due to direct output of the feedforward torque can be avoided, and the safety of starting operation of a driver is effectively improved.

Further, the feedforward torque is obtained according to a backward sliding speed table when the self-adaptive ramp auxiliary control function is activated.

The feedforward torque is obtained according to the backward sliding speed table when the self-adaptive ramp auxiliary control function is activated, so that the calculation cost can be effectively saved, and the reliability of feedforward torque obtaining is improved under the support of accurate data.

Further, after the self-adaptive ramp auxiliary control function exits at the set time, if the vehicle working condition state meets the activation condition, the self-adaptive ramp auxiliary control function is not activated any more.

In order to avoid the interaction of the re-activated self-adaptive ramp auxiliary control function and the control of the vehicle taken over by the driver, which leads to unexpected activation of the vehicle and jitter of the vehicle in running, and reduces driving comfort, the self-adaptive ramp auxiliary control function of the invention does not activate the self-adaptive ramp auxiliary control function any more no matter whether the driver has or not to control the action of the vehicle if the working condition state of the vehicle meets the activation condition after the self-adaptive ramp auxiliary control function exits at the set time.

Specifically, after the self-adaptive ramp auxiliary control function normally exits (the set time exits), the backward sliding speed of the vehicle backward slides firstly enters a range between a first set threshold value and a second set threshold value, at the moment, the self-adaptive ramp auxiliary control function is not activated any more, the situation that the driver takes over the control of the vehicle after the self-adaptive ramp auxiliary control function exits and the self-adaptive ramp auxiliary control function is influenced mutually, the vehicle is not expected to be activated, the vehicle shakes in running, and the driving comfort is reduced; the driver does not take over the vehicle in time when the backward sliding speed of the vehicle enters between the first set threshold value and the second set threshold value, so that the backward sliding speed of the vehicle exceeds the second set threshold value, if the driver starts to take over the vehicle and steps on the accelerator, the backward sliding speed of the vehicle enters between the first set threshold value and the second set threshold value again, and at the moment, the working condition state of the vehicle meets the activation condition, but the self-adaptive ramp auxiliary control function is not activated any more, and the unexpected activation of the self-adaptive ramp auxiliary control function is avoided.

When the self-adaptive ramp auxiliary control function normally exits (the set time exits), the backward sliding speed of the vehicle backward slides firstly enters between a first set threshold value and a second set threshold value, and at the moment, the self-adaptive ramp auxiliary control function is not activated any more, so that the phenomenon that the vehicle is started unexpectedly due to the fact that a driver takes over the control of the vehicle and the self-adaptive ramp auxiliary control function to influence each other after the self-adaptive ramp auxiliary control function exits is avoided, and the driving comfort is reduced; the driver does not take over the vehicle in time when the backward sliding speed of the vehicle falls between the first set threshold and the second set threshold, so that the backward sliding speed of the vehicle exceeds the second set threshold, if the vehicle slides backward to a flat road, the backward sliding speed gradually decreases, so that the backward sliding speed of the vehicle falls between the first set threshold and the second set threshold again, and at the moment, the working condition of the vehicle meets the activation condition, but the self-adaptive ramp auxiliary control function is not activated any more, and the unexpected activation of the self-adaptive ramp auxiliary control function is avoided.

That is, when the vehicle satisfies the activation condition again, the adaptive assist function is not activated regardless of whether the driver controls the vehicle.

If the vehicle is provided with a creeping function, the vehicle with the throttle creeping up a slope, creep torque is insufficient to drive the vehicle to creep up a slope when creeping up a slope to a big slope, the vehicle slides backward, and does not step on a throttle, and does not pull a handle brake, the activation condition is met, the self-adaptive ramp auxiliary control function is activated, the activated self-adaptive ramp auxiliary control function exits after a set time, the vehicle continues to slide backward, when the vehicle slides backward to a small slope, the vehicle moves forward under the effect of creep torque again after traveling to the big slope, the self-adaptive ramp auxiliary control function is activated again, and the operation is repeated.

In order to avoid repeated activation of the creeping function and the adaptive ramp auxiliary control function, when the vehicle is creeping up a slope, a driver does not control the vehicle, and the creeping torque of the vehicle creeping up the slope is insufficient to drive the vehicle to slide backward when the vehicle is climbing up the slope, so that the activation condition is met, the adaptive ramp auxiliary control function is activated, after the self-adaptive ramp auxiliary control function is withdrawn from the set time, if the working condition of the vehicle meets the activation condition within the set time before the driver does not control the vehicle, the adaptive ramp auxiliary control function is not activated any more, the unexpected activation of the vehicle is avoided, the shaking of the vehicle in the running process is caused, and the driving comfort is reduced; if the driver controls the vehicle, namely, after the driver steps on the accelerator, steps on the brake or steps on the brake and the like, the working condition of the vehicle meets the activation condition, the adaptive ramp auxiliary control function is not activated any more, the influence of the re-activated adaptive ramp auxiliary control function and the control of the driver taking over the vehicle is effectively avoided, the unexpected activation of the vehicle is caused, the shaking of the vehicle in running is caused, and the driving comfort is reduced.

Further, when the vehicle working condition state after stopping the vehicle braking meets the activation condition for the first time, the self-adaptive ramp auxiliary control function is activated.

The invention activates the self-adaptive ramp auxiliary control function when the vehicle with a brake signal slides backwards, but in order to avoid that a driver repeatedly meets the activation condition in the process of controlling the vehicle (stepping on the brake) for a long time, and then repeatedly activates the self-adaptive ramp auxiliary control function, reminds the driver to park by using a handbrake or other parking devices, and if the self-adaptive ramp auxiliary control function needs to be activated again, the driver needs to thoroughly step on (stop) the vehicle, and the self-adaptive ramp auxiliary control function is activated only when the working condition state of the vehicle meets the activation condition for the first time after the driver thoroughly steps on (stops).

The invention activates the self-adaptive ramp auxiliary control function when the vehicle with the accelerator pedal slides backwards, but in order to avoid that a driver repeatedly meets the activation condition in the process of controlling the vehicle (stepping the accelerator) for a long time, and then repeatedly activates the self-adaptive ramp auxiliary control function, reminding the driver to stop the vehicle by utilizing a hand brake or stepping a brake or other parking devices after releasing the accelerator, if the self-adaptive ramp auxiliary control function needs to be activated again, the vehicle needs to be thoroughly stepped on (braked and stopped), and the working condition of the vehicle after the vehicle is thoroughly stepped on (braked and stopped) meets the activation condition for the first time, then the self-adaptive ramp auxiliary control function is activated.

Further, the activation condition also includes that the vehicle is not open.

Because the activation time of the self-adaptive ramp auxiliary control function is shorter, if the self-adaptive ramp auxiliary control function is intervened (activated) in the open state, a driver considers that the vehicle is separated after being properly braked and stopped, so that potential safety hazards exist.

The invention provides an adaptive ramp auxiliary control system for a vehicle, which comprises a processor, wherein the processor is used for executing instructions to realize the adaptive ramp auxiliary control method for the vehicle.

The adaptive ramp auxiliary control system for the vehicle comprises a processor, wherein the processor is used for executing instructions to activate an adaptive ramp auxiliary control function when the current working condition state of the vehicle meets an activation condition. The activation condition of the existing self-adaptive ramp auxiliary control function is that the vehicle is in a backward sliding state, and is different from the existing activation condition, the activation condition of the self-adaptive ramp auxiliary control function comprises that when a brake signal is effective but the vehicle is in a backward sliding state, when the vehicle has braking force output, but the braking force is insufficient to support the vehicle to stay on a slope, the vehicle exits from a braking mode, the self-adaptive ramp auxiliary control function is activated, the self-adaptive ramp auxiliary control function timely outputs driving force to enable the vehicle to stay on the slope, and the self-adaptive ramp auxiliary control function timely engages with the condition that the braking force is insufficient to support the vehicle to stay on the slope when in service braking, so that the backward sliding distance of the vehicle when in ramp starting can be effectively reduced, the anti-sliding performance is improved, and the safety and the comfort of starting operation of a driver are improved.

Drawings

FIG. 1 is a block flow diagram of an adaptive hill assist control method for a vehicle of the present invention.

Detailed Description

The present invention will be further described in detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent.

An embodiment of an adaptive hill assist control method for a vehicle:

the adaptive ramp auxiliary control function is activated when the current vehicle working condition state meets the activation condition, wherein the activation condition comprises that the vehicle is in a backward running state, and the activation condition further comprises that a brake signal is valid.

The activation condition of the existing self-adaptive ramp auxiliary control function is that the vehicle is in a backward sliding state, namely, the vehicle is in the backward sliding state when the vehicle does not step on the accelerator and does not pull the hand for braking, or the vehicle is in the backward sliding state when the vehicle steps on the accelerator and does not pull the hand for braking, or the vehicle is in the backward sliding state when the vehicle does not open the door and does not pull the hand for braking, or the vehicle is in the backward sliding state when the vehicle opens the door and does not pull the hand for braking, and the like.

Different from the existing activation conditions, the activation conditions of the self-adaptive ramp auxiliary control function comprise that when a brake signal is effective but the vehicle is in a backward sliding state, when the vehicle has braking force output, but the braking force is insufficient to support the vehicle to stay on a slope, the self-adaptive ramp auxiliary control function is activated, the self-adaptive ramp auxiliary control function timely outputs driving force to enable the vehicle to stay on the slope, and the situation that the braking force is insufficient to support the vehicle to stay on the slope during running braking is timely linked, so that the backward sliding distance of the vehicle during hill starting can be effectively reduced, the anti-slip performance is improved, and the safety and the comfort of starting operation of a driver are improved.

Because the activation time of the self-adaptive ramp auxiliary control function is shorter, if the self-adaptive ramp auxiliary control function is intervened (activated) in the open state, a driver considers that the vehicle is separated after being properly braked and stopped, so that potential safety hazards exist. That is, the activation condition of the present invention includes when the brake signal is active and the vehicle is not open, but the vehicle is in a rollback state.

The backward running state is determined by the following modes: the motor rotation direction of the actual gear requirement of the vehicle is inconsistent with the motor actual rotation direction, and the vehicle speed exceeds a first set threshold value and does not exceed a second set threshold value.

When the adaptive ramp auxiliary control function is activated, the feedforward torque for preventing the vehicle from sliding is obtained and transmitted to the motor controller, and the motor controller combines the feedforward torque and adopts a closed-loop zero-rotation speed control method to realize the control of the vehicle from sliding. The invention interactively and cooperatively controls the vehicle to park by the motor controller and the whole vehicle controller, and can ensure the reliability of the activation time of the self-adaptive ramp auxiliary control function for vehicles which cannot accurately identify the gradient and are not provided with an ESP, effectively reduce the backward slip distance of the vehicle during hill start, improve the anti-slip performance and improve the safety and comfort of the starting operation of a driver.

The self-adaptive ramp auxiliary control function is activated, the backward sliding speed exceeds a third set threshold, and the feedforward torque is output in a fixed step size every cycle.

And taking a third set threshold value set for the backward sliding speed as a determining factor of the feedforward torque to increase the fixed step output every cycle, namely, increasing the feedforward torque to increase the fixed step output every cycle when the backward sliding speed before the adaptive ramp auxiliary control function is activated exceeds the third set threshold value. The third setting threshold can be obtained according to off-line calibration.

More specifically, the third set threshold is smaller than the second set threshold and larger than the first set threshold. The third set threshold value should be set to a value close to the second set threshold value according to off-line calibration, and at the moment, the feedforward torque is output in a fixed step length every cycle, so that the phenomenon that the feedforward torque is directly output to cause forward running of the vehicle is avoided, and the safety of starting operation of a driver is effectively improved.

The feedforward torque is obtained according to a backward sliding speed table when the self-adaptive ramp auxiliary control function is activated.

The closed-loop zero rotation speed control method comprises a PI closed-loop zero rotation speed control method capable of effectively improving control efficiency, a PID closed-loop zero rotation speed control method capable of effectively improving system stability and accuracy, a fuzzy PI closed-loop zero rotation speed control method which is simple and convenient to apply and high in applicability, and a fuzzy PI closed-loop zero rotation speed control method capable of solving the limitation of traditional control in practical application.

After the self-adaptive ramp auxiliary control function exits at the set time, if the vehicle working condition state meets the activation condition, the self-adaptive ramp auxiliary control function is not activated any more.

In order to avoid the interaction of the re-activated self-adaptive ramp auxiliary control function and the control of the vehicle taken over by the driver, which leads to unexpected activation of the vehicle and jitter of the vehicle in running, and reduces driving comfort, the self-adaptive ramp auxiliary control function of the invention does not activate the self-adaptive ramp auxiliary control function any more no matter whether the driver has or not to control the action of the vehicle if the working condition state of the vehicle meets the activation condition after the self-adaptive ramp auxiliary control function exits at the set time.

Specifically, after the self-adaptive ramp auxiliary control function normally exits (the set time exits), the backward sliding speed of the vehicle backward slides firstly enters a range between a first set threshold value and a second set threshold value, at the moment, the self-adaptive ramp auxiliary control function is not activated any more, the situation that the driver takes over the control of the vehicle after the self-adaptive ramp auxiliary control function exits and the self-adaptive ramp auxiliary control function is influenced mutually, the vehicle is not expected to be activated, the vehicle shakes in running, and the driving comfort is reduced; the driver does not take over the vehicle in time when the backward sliding speed of the vehicle enters between the first set threshold value and the second set threshold value, so that the backward sliding speed of the vehicle exceeds the second set threshold value, if the driver starts to take over the vehicle and steps on the accelerator, the backward sliding speed of the vehicle enters between the first set threshold value and the second set threshold value again, and at the moment, the working condition state of the vehicle meets the activation condition, but the self-adaptive ramp auxiliary control function is not activated any more, and the unexpected activation of the self-adaptive ramp auxiliary control function is avoided.

When the self-adaptive ramp auxiliary control function normally exits (the set time exits), the backward sliding speed of the vehicle backward slides firstly enters between a first set threshold value and a second set threshold value, and at the moment, the self-adaptive ramp auxiliary control function is not activated any more, so that the phenomenon that the vehicle is started unexpectedly due to the fact that a driver takes over the control of the vehicle and the self-adaptive ramp auxiliary control function to influence each other after the self-adaptive ramp auxiliary control function exits is avoided, and the driving comfort is reduced; the driver does not take over the vehicle in time when the backward sliding speed of the vehicle falls between the first set threshold and the second set threshold, so that the backward sliding speed of the vehicle exceeds the second set threshold, if the vehicle slides backward to a flat road, the backward sliding speed gradually decreases, so that the backward sliding speed of the vehicle falls between the first set threshold and the second set threshold again, and at the moment, the working condition of the vehicle meets the activation condition, but the self-adaptive ramp auxiliary control function is not activated any more, and the unexpected activation of the self-adaptive ramp auxiliary control function is avoided.

That is, when the vehicle satisfies the activation condition again, the adaptive assist function is not activated regardless of whether the driver controls the vehicle.

If the vehicle is provided with a creeping function, the vehicle with the throttle creeping up a slope, creep torque is insufficient to drive the vehicle to creep up a slope when creeping up a slope to a big slope, the vehicle slides backward, and does not step on a throttle, and does not pull a handle brake, the activation condition is met, the self-adaptive ramp auxiliary control function is activated, the activated self-adaptive ramp auxiliary control function exits after a set time, the vehicle continues to slide backward, when the vehicle slides backward to a small slope, the vehicle moves forward under the effect of creep torque again after traveling to the big slope, the self-adaptive ramp auxiliary control function is activated again, and the operation is repeated.

In order to avoid repeated activation of the creeping function and the adaptive ramp auxiliary control function, when the vehicle is creeping up a slope, a driver does not control the vehicle, and the creeping torque of the vehicle creeping up the slope is insufficient to drive the vehicle to slide backward when the vehicle is climbing up the slope, so that the activation condition is met, the adaptive ramp auxiliary control function is activated, after the self-adaptive ramp auxiliary control function is withdrawn from the set time, if the working condition of the vehicle meets the activation condition within the set time before the driver does not control the vehicle, the adaptive ramp auxiliary control function is not activated any more, the unexpected activation of the vehicle is avoided, the shaking of the vehicle in the running process is caused, and the driving comfort is reduced; if the driver controls the vehicle, namely, after the driver steps on the accelerator, steps on the brake or steps on the brake and the like, the working condition of the vehicle meets the activation condition, the adaptive ramp auxiliary control function is not activated any more, the influence of the re-activated adaptive ramp auxiliary control function and the control of the driver taking over the vehicle is effectively avoided, the unexpected activation of the vehicle is caused, the shaking of the vehicle in running is caused, and the driving comfort is reduced.

When the vehicle working condition state after stopping the vehicle braking meets the activation condition for the first time, the self-adaptive ramp auxiliary control function is activated.

The invention activates the self-adaptive ramp auxiliary control function when the vehicle with a brake signal slides backwards, but in order to avoid that a driver repeatedly meets the activation condition in the process of controlling the vehicle (stepping on the brake) for a long time, and then repeatedly activates the self-adaptive ramp auxiliary control function, reminds the driver to park by using a handbrake or other parking devices, and if the self-adaptive ramp auxiliary control function needs to be activated again, the driver needs to thoroughly step on (stop) the vehicle, and the self-adaptive ramp auxiliary control function is activated only when the working condition state of the vehicle meets the activation condition for the first time after the driver thoroughly steps on (stops).

The invention activates the self-adaptive ramp auxiliary control function when the vehicle with the accelerator pedal slides backwards, but in order to avoid that a driver repeatedly meets the activation condition in the process of controlling the vehicle (stepping the accelerator) for a long time, and then repeatedly activates the self-adaptive ramp auxiliary control function, reminding the driver to stop the vehicle by utilizing a hand brake or stepping a brake or other parking devices after releasing the accelerator, if the self-adaptive ramp auxiliary control function needs to be activated again, the vehicle needs to be thoroughly stepped on (braked and stopped), and the working condition of the vehicle after the vehicle is thoroughly stepped on (braked and stopped) meets the activation condition for the first time, then the self-adaptive ramp auxiliary control function is activated.

Specifically, motor drive anti-slip control of the vehicle is realized by adopting a control method of interaction cooperation of a motor controller and a whole vehicle controller, the whole vehicle controller calculates feed-forward torque of the anti-slip by combining the working condition state of the vehicle and the backward sliding speed of the vehicle, the feed-forward torque is transmitted to the motor controller through a message, and the motor controller realizes the anti-slip control of the vehicle by combining the feed-forward torque transmitted by the whole vehicle controller and a PID closed loop zero rotation speed control method. By the technology, the backward sliding distance of the vehicle during hill start can be reduced, and convenience and safety of starting operation of a driver are improved. The method comprises the following specific steps:

step one: the vehicle controller judges whether the vehicle activates the self-adaptive ramp auxiliary control function according to the vehicle information;

step two: when the function is activated, the whole vehicle controller calculates the feedforward torque and transmits the feedforward torque to the motor controller, and the motor controller combines the feedforward torque sent by the whole vehicle controller to realize the anti-slip control of the vehicle through a PID closed-loop zero-rotation speed control method;

step three: the vehicle controller judges whether the vehicle exits the self-adaptive ramp auxiliary control function according to the vehicle information;

step four: and the function is withdrawn, the zero-rotation speed control mode of the motor controller is withdrawn, and the whole vehicle controller continues to control the vehicle to run through the torque control mode.

The self-adaptive ramp auxiliary control function has four states: not activated; activating; slowly exiting; and (5) quickly exiting. The specific implementation mode is as follows:

step one: the vehicle controller receives signals of a motor controller, a brake, an accelerator, a hand brake, a gear, a door and the like, and judges that (1) when the vehicle is in a backward sliding state, does not step on the accelerator, does not pull the brake and does not open the door, or (2) the vehicle steps on a slope to stop, the backward sliding speed is smaller than a set threshold (a fourth set threshold is a minimum value for determining whether the vehicle is completely stopped or not), and the self-adaptive ramp auxiliary control function is activated when the vehicle does not pull the brake, does not open the door and releases the brake. Wherein:

and (5) backward slip judgment: when the actual motor rotation direction of the vehicle is inconsistent with the actual motor rotation direction, and the vehicle speed exceeds a set threshold (a first set threshold is set with respect to the vehicle speed) and does not exceed a second set threshold (a second set threshold is set with respect to the vehicle speed, the first set threshold is smaller than the second set threshold), the vehicle is judged to be in a backward running state.

When the brake signal is effective all the time but the vehicle is backward running, the self-adaptive ramp auxiliary control function is activated, and the function is automatically exited after a set time. In this scenario, if the adaptive ramp auxiliary control function needs to be activated again, the vehicle needs to be completely stepped on and stopped.

When the vehicle equipped with the creep function goes up a slope, in order to avoid the vehicle switching back and forth between the creep and the adaptive ramp auxiliary control function (loose throttle in small slope, activate creep, vehicle up slope, when slope increases, creep torque is insufficient to drive the vehicle up slope, vehicle backward slip, activate the adaptive ramp auxiliary control function, if there is no action, automatically exit the adaptive ramp auxiliary control function after a set time, the vehicle continues to activate creep when sliding down slope to small slope, and so cycle repeatedly), when creep up slope backward slip activates the adaptive ramp auxiliary control function, the adaptive ramp auxiliary control function will not be activated again if there is no action after the function exits.

When the vehicle goes uphill and normally activates the self-adaptive ramp auxiliary control function, the vehicle exits after the set time, the vehicle slides backward, the accelerator is stepped on at the moment, and the backward sliding speed of the vehicle enters the set activation speed interval again from being greater than the first set threshold value, the self-adaptive ramp auxiliary control function is not activated.

When the self-adaptive ramp auxiliary control function is released from braking during the exiting process, namely, when the self-adaptive ramp auxiliary control function is not completely exited, and the rear sliding speed is smaller than a set value (a second set threshold value), the function is activated again.

Step two: the self-adaptive ramp auxiliary control function is activated, the whole vehicle controller obtains feedforward torque and transmits the feedforward torque to the motor controller, and the motor controller combines the feedforward torque to realize the anti-slip control of the vehicle through a PID closed-loop zero-rotation speed control method. Wherein:

feedforward torque calculation mode: when the self-adaptive ramp auxiliary control function is activated, the feedforward torque is output according to a rear-sliding vehicle quick look-up table.

When the self-adaptive ramp auxiliary control function exits, namely, when the self-adaptive ramp auxiliary control function is not completely exited, the brake is released, the backward sliding speed is smaller than the set value (second set threshold value) and exceeds the set threshold value (first set threshold value), the self-adaptive ramp auxiliary control function is activated again, when the backward sliding speed is large, the lookup table can obtain large feedforward torque, and at the moment, in order to avoid the direct output of the excessive feedforward torque, the feedforward torque is output in a fixed step size by each cycle.

And the feedforward torque under other working conditions is directly output.

The feedforward torque output is cancelled when the adaptive hill assist control function exits.

When the self-adaptive ramp auxiliary control function is activated, the whole vehicle controller transmits feedforward torque, a required motor control mode, a required motor rotation direction, a required motor working mode and a motor target rotation speed 0 to the motor controller, and the motor controller combines the feedforward torque, realizes the anti-slip control of the vehicle through a PID closed loop zero rotation speed control method and feeds back the actual state of the motor to the whole vehicle controller.

Step three: after the self-adaptive ramp auxiliary control function is activated, the whole vehicle controller judges whether the exit condition is met according to the vehicle state in real time, if so, the motor controller exits from the zero rotation speed control mode, the whole vehicle controller combines the actual output torque of the motor at the moment, judges the exit mode according to the running working condition of the whole vehicle, outputs the torque change to the motor controller, and the motor controller controls the running of the vehicle by responding to the required torque transmitted by the whole vehicle controller.

The exit process is divided into three modes, namely direct exit (the whole vehicle controller does not consider the actual torque when the motor controller exits the zero rotation speed control mode, and is directly taken over by braking torque or driving torque or other torques such as creeping torque), quick exit (the whole vehicle controller records the actual torque when the motor controller exits the zero rotation speed control mode and exits at a larger speed, the motor controller responds, the problems of untimely torque exit, motor overtemperature and the like during gear shifting are avoided) and slow exit (the whole vehicle controller records the actual torque when the motor controller exits the zero rotation speed control mode and exits at a smaller speed, and the motor controller responds and ensures the driving comfort of the vehicle). Wherein:

after the self-adaptive ramp auxiliary control function is activated, if no action exists, the self-adaptive ramp auxiliary control function automatically slowly exits after a set time. The adaptive hill-hold control function provides the driver with foot-change time only when the vehicle is started on a hill, and cannot stay on the hill for a long time, so the set activation time (i.e., set time) is relatively small.

The adaptive ramp auxiliary control function is directly exited when the following conditions are met: the accelerator is stepped on, the driving torque is larger than the actual torque of the motor, and if the accelerator is stepped on, the vehicle can slide backwards, so that the driving comfort is reduced; when the vehicle has a creeping function and the creeping torque is larger than the actual output torque of the motor, the self-adaptive ramp auxiliary control function directly exits, and as the vehicle is regulated for a certain time when the function is activated and stably resides on the slope, a certain time is required to be delayed, and after the vehicle stably resides on the slope, whether the creeping torque is larger than the actual output torque of the motor is judged.

The adaptive ramp assist control function enters the quick exit mode when activated satisfying the following conditions: neutral gear, or pull brake. The driving torque is required to be withdrawn as soon as possible after the neutral gear is returned, so that the problem that the torque is not connected after a driver immediately hangs gears in opposite directions is avoided; when the handle is braked, the vehicle does not need the motor to output driving force to control the vehicle to stay on a slope any more, and at the moment, the torque is quickly withdrawn, so that the risk of overtemperature of the motor is reduced.

When the vehicle realizes the slope assistance through motor control, judging the vehicle state, and exiting the slope assistance according to the vehicle state by adopting one or more of the following modes: (1) if the vehicle state is that no action exists in the set time, slowly exiting the slope assistance; the slow exit ramp assists in: the actual torque output by the motor before exiting the hill assist is recorded, and the actual torque output by the motor is reduced at a rate less than the set rate to finally exit the hill assist.

(2) If the vehicle state is the response control command and the corresponding obtained new driving torque is larger than the actual torque output by the current hill auxiliary control (driving) motor, directly exiting hill auxiliary; the direct exit ramp assists in: the motor directly outputs the new driving torque.

(3) If the vehicle state is a return neutral gear and/or a handle brake, quickly exiting the hill way assistance; the quick exit ramp assists in: the actual torque output by the motor before the hill-drop assistance is recorded, the torque output by the driving motor is reduced at a rate greater than the set rate, and finally the hill-drop assistance is performed.

Namely, the exit of the vehicle adaptive hill assist control function is classified into three types: (1) direct exit, (2) fast exit, and (3) slow exit.

Wherein, directly exit: the whole vehicle controller directly takes over other torque such as braking torque or driving torque or creeping torque without considering actual torque when the motor controller exits from the zero rotation speed control mode.

Specifically, if the vehicle state is in response to the control command and the corresponding obtained new driving torque is greater than the actual torque output by the current hill auxiliary driving motor, the hill auxiliary is directly exited.

Wherein the control instruction of the vehicle response comprises: the driver steps on the accelerator, namely, the new driving torque obtained by the motor is larger than the actual torque of the motor (the actual torque of the current hill-assist driving motor) when stepping on the accelerator, so that the phenomenon that the vehicle slips backwards caused by the direct withdrawal of the accelerator-stepping hill-assist is avoided, namely, the vehicle slips backwards still when the vehicle is started on a hill due to insufficient driving force (driving torque) output by stepping on the accelerator to support the vehicle to normally run after parking on the hill is avoided, and the driving comfort and safety are reduced; wherein, the driving torque output by stepping on the accelerator is taken as the new driving torque.

The control instructions for the vehicle response further include: the new driving torque obtained by the motor during creeping is larger than the actual torque of the motor, so that backward running of the vehicle caused by the direct exit of the auxiliary creeping ramp is avoided, namely, the backward running still occurs when the vehicle creep up the slope due to insufficient creeping torque output by creeping to support the vehicle to reside on the slope, and the driving comfort and safety are reduced; wherein, creep torque is used as new driving torque; because the vehicle is stabilized and parked for a certain time to adjust when the ramp auxiliary function is activated, a certain time is needed to delay, namely, after the vehicle is stabilized and parked for a certain time, whether the creep torque is larger than the actual output torque of the motor is judged.

The control instructions for the vehicle response further include: service braking, namely when the vehicle is parked by the hill-hold assist, the driver can park the vehicle due to the fact that the driver steps on the braking torque output by the brake (service braking) in time within the foot change time provided by the hill-hold assist, namely the braking torque is larger than the actual torque actually output by the hill-hold assist control motor, so that the situation that the driver steps on the braking torque output by the brake to support the vehicle to park the vehicle is avoided, the vehicle slides backwards, and driving comfort and safety are reduced; wherein the braking torque output by stepping on the brake is used as the new driving torque.

The control instruction of the vehicle response in this embodiment includes any one or any combination of the above.

Quick exit: the whole vehicle controller records the actual torque when the motor controller exits from the zero rotation speed control mode, exits at a larger speed, and is responded by the motor controller, so that the problems of untimely torque exiting, motor overtemperature and the like during gear shifting are avoided.

Specifically, if the vehicle condition is a reverse gear and/or a pull brake, the vehicle hill assist is quickly exited.

The vehicle state is a return gear, the vehicle is required to exit the vehicle ramp assistance as soon as possible, the problem that the torque is not connected after a driver immediately hangs gears in opposite directions is avoided, namely, the motor is still controlled to output driving torque by the ramp assistance, and cannot timely connect and timely output driving torque which is output by the gear control in opposite directions and is opposite to the driving torque output by the ramp assistance control.

The vehicle state is handle braking, and the motor is not required to output driving force to control the vehicle to stay on a slope when the vehicle handle braking is considered, so that the vehicle is still required to quickly exit the vehicle ramp for assistance, and the risk of overtemperature of the motor is reduced.

Slowly exit: the whole vehicle controller records the actual torque when the motor controller exits from the zero rotation speed control mode, exits from the zero rotation speed control mode at a small speed, and the motor controller responds to ensure the driving comfort of the vehicle.

Specifically, the driver does not have any action within a set time after the vehicle adaptive hill assist control function is activated, and the hill assist is automatically slowly exited. The adaptive hill-hold control function only provides a foot-changing time for a driver when the vehicle is started on a hill, and cannot stay on the hill for a long time, so that the set activation time (i.e., the set time) is relatively small.

When the adaptive ramp auxiliary control function is activated, the feedforward torque for preventing the vehicle from sliding is obtained and transmitted to the motor controller, and the motor controller combines the feedforward torque and adopts a closed-loop zero-rotation speed control method to realize the control of the vehicle from sliding. The invention interactively and cooperatively controls the vehicle to park by the motor controller and the whole vehicle controller, and can ensure the reliability of the activation time of the self-adaptive ramp auxiliary control function for vehicles which cannot accurately identify the gradient and are not provided with an ESP, effectively reduce the backward slip distance of the vehicle during hill start, improve the anti-slip performance and improve the safety and comfort of the starting operation of a driver.

When the back sliding speed is smaller than a set threshold value in the process of the hill auxiliary exit to activate the hill auxiliary, the feedforward torque of the hill auxiliary is output in a fixed step length every cycle.

And taking the set threshold value set for the backward vehicle sliding speed in the process of the hill-drop auxiliary exit as a determining factor for increasing the output of the fixed step length every cycle of the feedforward torque of the hill-drop auxiliary exit, namely increasing the output of the feedforward torque of the hill-drop auxiliary at the fixed step length every cycle when the backward vehicle sliding speed in the process of the hill-drop auxiliary exit is smaller than the set threshold value and the hill-drop auxiliary is activated. The setting of the set threshold value can be obtained according to off-line calibration.

More specifically, the backward traveling speed as a determination condition for activating the hill assist activates the hill assist within a certain range, such as the backward traveling speed exceeding a smaller value and not exceeding a larger value, and the set threshold value is set for the larger value (the highest value of the aforementioned backward traveling speed), that is, the set threshold value is smaller than the larger value. The set threshold value is set to be a value close to a larger value according to off-line calibration, and the ramp auxiliary feedforward torque is output in a fixed step length every cycle, so that the phenomenon that the vehicle is rushed forward due to direct output of the feedforward torque is avoided, and the safety of starting operation of a driver is effectively improved.

The feedforward torque is obtained according to a backward sliding speed table when the self-adaptive ramp auxiliary control function is activated.

Step four: after the self-adaptive ramp auxiliary control function is completely withdrawn, the motor controller withdraws from the zero-rotation speed control mode, and the motor controller controls the vehicle to run by responding to the required torque transmitted by the whole vehicle controller.

According to the invention, the motor controller and the whole vehicle controller are adopted to realize motor-driven anti-slip control of the vehicle, a specific time and a specific exit mode for activating the self-adaptive hill auxiliary control function are provided, the backward slip distance of the vehicle during hill start can be reduced by the technology, and the convenience and safety of starting operation of a driver are improved. The invention provides a self-adaptive ramp auxiliary control function comprising reverse gear and creeping, so as to improve the convenience and safety of reverse gear and uphill starting operation of a driver.

According to the invention, the activation condition is used for determining the activation time of the self-adaptive ramp auxiliary control function, the motor controller and the whole vehicle controller are used for interactively and cooperatively controlling the vehicle to park, and for vehicles which cannot accurately identify the gradient and are not provided with the ESP, the reliability of the activation time of the self-adaptive ramp auxiliary control function can be ensured, the backward slip distance of the vehicle during the hill start is effectively reduced, the anti-slip performance is improved, and the safety and the comfort of the starting operation of a driver are improved.

An embodiment of an adaptive hill assist control system for a vehicle:

an adaptive hill assist control system for a vehicle includes a processor for executing instructions to implement an adaptive hill assist control method for a vehicle as described above. The adaptive hill assist control method for a vehicle is described in detail in an embodiment of an adaptive hill assist control method for a vehicle, and will not be described here.

Claims (9)

1. An adaptive ramp assist control method for a vehicle, wherein an adaptive ramp assist control function is activated when a current vehicle operating condition state satisfies an activation condition, the activation condition including the vehicle being in a rollback state, is characterized in that the activation condition further includes a brake signal being active.

2. An adaptive hill assist control method for a vehicle according to claim 1, wherein the backward slip state is determined by: the motor rotation direction of the actual gear requirement of the vehicle is inconsistent with the motor actual rotation direction, and the vehicle speed exceeds a first set threshold value and does not exceed a second set threshold value.

3. An adaptive hill assist control method for a vehicle as defined in claim 1, wherein when the adaptive hill assist control function is activated, the overall vehicle controller obtains a feed-forward torque for anti-slip and transmits the feed-forward torque to a motor controller, and the motor controller adopts a closed-loop zero-speed control method in combination with the feed-forward torque to realize anti-slip control of the vehicle.

4. An adaptive hill assist control method for a vehicle as defined in claim 3, wherein the post-roll speed of the adaptive hill assist control function before activation exceeds a third set threshold, and the feedforward torque is output in fixed steps of increments per cycle.

5. An adaptive hill assist control method for a vehicle according to claim 3 wherein the feed forward torque is derived from a look-up table of the rear roll upon activation of the adaptive hill assist control function.

6. An adaptive hill assist control method for a vehicle according to claim 1 or 2, wherein the adaptive hill assist control function is not activated any more after the set time has elapsed if the vehicle condition state satisfies the activation condition.

7. The adaptive hill assist control method for a vehicle according to claim 6, wherein the adaptive hill assist control function is activated when a vehicle operating condition state after a stop of vehicle braking satisfies an activation condition for the first time.

8. An adaptive ramp assist control method for a vehicle as defined in claim 1 wherein the activation condition further includes the vehicle not opening the door.

9. An adaptive hill assist control system for a vehicle, comprising a processor for executing instructions to implement an adaptive hill assist control method for a vehicle as claimed in any one of claims 1 to 8.