A method and system for solving the pull compensation of vehicle running deviation

Abstract

The application discloses a kind of to solve the pulling compensation method and system of vehicle running deviation, method specifically includes: whether target vehicle meets the pulling compensation function activation condition;If yes, according to the difference between current target vehicle driver hand force and preset target hand force, the target compensation rack force of target vehicle is obtained by the conversion of mechanical relationship, long time and short time rack force learning is carried out simultaneously, to obtain long time learning rack force and short time learning rack force, the long time learning rack force and short time learning rack force are used to learn to the target compensation rack force;Long time learning rack force and short time learning rack force are superimposed to obtain compensation rack force, compensation rack force is converted by mechanical relationship, and first motor compensation torque is calculated;One aspect of the application can reduce the hand force of driver when maintaining vehicle straight, on the other hand, when driver hand leaves steering wheel, the ability of vehicle to keep straight driving can be improved by compensation rack force.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of intelligent automobile control, in particular to a pulling compensation method and system for solving vehicle running deviation. BACKGROUND

[0002] According to the requirements of the Highway Subgrade Drainage Design Specification issued by the Ministry of Communications, in order to consider the road drainage needs, the design of the road is generally high in the middle and low on both sides, and the transverse slope is generally 2%. When the automobile runs on such a road, it is easy to deviate to the direction with low slope. Under long-time high-speed driving, the running deviation of the vehicle not only aggravates the tire wear (consumption) and affects the service life of the tire, but also requires the driver to exert a reverse hand torque on the steering wheel for a long time to maintain the normal driving of the vehicle, which not only increases the fatigue driving of the driver, but also brings safety hazards to the driving of the automobile. At present, the PDC (deviation compensation function) is generally used to provide a corresponding compensation torque to reduce the hand force and eliminate the fatigue of the driver. However, when the PDC (deviation compensation function) provides the compensation torque, when the vehicle changes the driving direction, the compensation torque may produce a significant reverse pulling force, thereby affecting the driving comfort, for example, when changing lanes, turning, especially when driving S-curve on mountain roads. SUMMARY

[0003] The present application aims to improve and innovate in view of the shortcomings and problems in the background art, and provides a pulling compensation method and system for solving vehicle running deviation.

[0004] To achieve the above-mentioned purpose, according to the first aspect of the present application, the present application provides a pulling compensation method for solving vehicle running deviation, which specifically comprises:

[0005] determining whether the target vehicle meets the pulling compensation function activation condition;

[0006] If yes, according to the difference between the current target vehicle driver hand force and the preset target hand force, the target compensation rack force of the target vehicle is obtained through mechanical relationship conversion, and long-time and short-time rack forces are learned to obtain long-time learning rack force and short-time learning rack force, which are used for learning to the target compensation rack force;

[0007] The long-time learning rack force and the short-time learning rack force are superimposed to obtain a compensation rack force, and the compensation rack force is converted through mechanical relationship to calculate a first motor compensation torque;

[0008] If no, it is determined whether the vehicle speed, steering wheel angle, longitudinal acceleration, yaw angular velocity and driver hand force of the target vehicle are normal and effective;

[0009] When the vehicle speed, steering wheel angle, longitudinal acceleration, yaw rate and driver hand force of the target vehicle are normal and effective, the learning of the long-time and short-time rack forces is stopped, and the compensation rack force is maintained as the long-time learning rack force at the previous time;

[0010] The long-time learning rack force at the previous time is converted by a mechanical relationship to calculate a second motor compensation torque.

[0011] When the vehicle speed, steering wheel angle, longitudinal acceleration, yaw rate and driver hand force of the target vehicle are not normal and effective, the output of the compensation rack force is stopped, and the motor compensation torque is reduced to zero;

[0012] The compensation function activation condition includes that the vehicle speed, steering wheel angle, longitudinal acceleration, yaw rate and driver hand force of the target vehicle are within a preset value range, and the target vehicle is straight in the side wind and road camber conditions.

[0013] According to the above technical solution, by setting the pull compensation function activation condition as the vehicle speed, steering wheel angle, longitudinal acceleration, yaw rate and driver hand force of the target vehicle being within a preset value range, the target vehicle can learn the long-time and short-time rack forces when it is straight in the side wind and road camber conditions, and the gradient of the long-time and short-time rack force learning is large, the learning is fast, the vehicle running deviation caused by the vehicle suspension and the like can be compensated, and the vehicle running deviation caused by the road camber or long-time side wind can also be compensated; the long-time and short-time learning rack forces can reduce the driver's hand force when the driver maintains the vehicle straight, and the compensation rack force can improve the vehicle's ability to keep straight when the driver's hand is away from the steering wheel; when the vehicle is turning or changing lanes, the learning of the long-time and short-time rack forces is stopped, and the compensation rack force is maintained as the long-time learning rack force at the previous time, which can provide a compensation rack force to reduce the hand force and eliminate the driver's fatigue, and can also avoid the continuous learning of the rack force when turning, especially in S-bends, to eliminate the excessive compensation rack force in the bend turning straight or the bend turning in the opposite direction, and to provide obvious opposite direction pulling force to cause bad hand feeling.

[0014] Further, the step of simultaneously learning the long-time and short-time rack forces specifically includes:

[0015] Calibrating a long-time rack force learning speed L1 and a short-time rack force learning speed S1;

[0016] The long-time rack force f1 is obtained by time integration according to a long-time rack force learning speed L1, when the driver hand force is greater than the preset target hand force and the steering wheel turns left or the driver hand force is less than the preset target hand force and the steering wheel turns right, ; when the driver hand force is less than the preset target hand force and the steering wheel turns left or the driver hand force is greater than the preset target hand force and the steering wheel turns right, ;

[0017] The short-time rack force f2 is obtained by time integration according to a short-time rack force learning speed S1, when the driver hand force is greater than the preset target hand force and the steering wheel turns left or the driver hand force is less than the preset target hand force and the steering wheel turns right, ; when the driver hand force is less than the preset target hand force and the steering wheel turns left or the driver hand force is greater than the preset target hand force and the steering wheel turns right, ;

[0018] Wherein S1=k*L1, k is a constant greater than 1, the units of L1 and S1 are KN / s, the units of f1 and f2 are KN, f 10 is the long-time learning rack force corresponding to the previous moment, f 20 is the short-time learning rack force corresponding to the previous moment.

[0019] From the above technical solution, the long-time and short-time learning rack forces corresponding to the current driver hand force are obtained based on the long-time and short-time learning rack forces of the previous moment, so that the compensation rack force is soft and has no hysteresis, and the discomfort feeling of the driver is avoided when the pull compensation function is activated to maintain the target vehicle straight driving; and the rack forces obtained by long-time and short-time learning can be adjusted in real time, so that the current driver hand force is consistent with the preset target hand force, and the comfort of the driver in the straight driving process is improved.

[0020] Further, the step of superimposing the long-time learning rack force and the short-time learning rack force to obtain the compensation rack force, and converting the compensation rack force through a mechanical relationship to calculate the first motor compensation torque specifically includes:

[0021] ;

[0022]

[0023] t1: the first motor compensation torque value, unit: Nm;

[0024] f: compensation rack force, unit: KN;

[0025] C: the angle transmission ratio of the steering gear rack line, unit: mm / rev;

[0026] η: system transmission efficiency, usually 0.93.

[0027] N: reduction ratio of the turbine worm

[0028] Further, the step of calibrating the long-time rack force learning speed L1 and the short-time rack force learning speed S1 specifically includes:

[0029] The target vehicle is controlled to drive straight on a 2% slope dry road surface, and the tire pressure is calibrated according to the design state;

[0030] The speed of the target vehicle is accelerated to 40 kph;

[0031] The long-time rack force learning speed L1 and the short-time rack force learning speed S1 are set;

[0032] After the pull compensation function of the target vehicle is activated, the vehicle is maintained to drive straight on the center line of the lane for 5 s,

[0033] The steering wheel is released, the vehicle deviation driving state is observed, the target vehicle TTT is recorded, and the test is repeated 5-10 times;

[0034] After the pull compensation function of the target vehicle is activated, the vehicle is maintained to drive straight on the center line of the lane for 5 s, the vehicle is maintained to drive straight, the target vehicle TTD is recorded, and the test is repeated 5-10 times;

[0035] Whether the TTT and the TTD of the target vehicle meet the requirements is judged;

[0036] If yes, the set long-time rack force learning speed L1 and the short-time rack force learning speed S1 meet the requirements, and the rack force learning speed L1 and the short-time rack force learning speed S1 are used for long-time and short-time rack force learning of the target vehicle in a low-speed working condition;

[0037] If no, the set long-time rack force learning speed L1 and the short-time rack force learning speed S1 are modified.

[0038] From the above technical solution, the long-time rack force learning speed L1 and the short-time rack force learning speed S1 are calibrated by the hand force TTT of the driver of the target vehicle to maintain the vehicle to drive straight and the time TTD of the vehicle to deviate laterally by 1 m when the driver's hand is removed from the steering wheel. When the long-time rack force learning speed L1 and the short-time rack force learning speed S1 obtained by calibration are used for long-time and short-time rack force learning, on the one hand, the hand force of the driver to maintain the vehicle to drive straight can be reduced, so that the reduced hand force can avoid vehicle deviation, and on the other hand, the compensation rack force can keep the vehicle to maintain straight driving when the driver's hand is removed from the steering wheel.

[0039] Further, the step of calibrating the long-time rack force learning speed L1 and the short-time rack force learning speed S1 specifically includes:

[0040] Control the target vehicle to travel in a long straight line on a dry road with a 2% slope, and calibrate the tire pressure according to the design state;

[0041] Accelerate the target vehicle to 80 kph;

[0042] Set the long-term rack force learning speed L1 and the short-term rack force learning speed S1;

[0043] After activating the target vehicle drag compensation function, maintain the vehicle's straight-line driving on the lane centerline for 5 seconds.

[0044] Release the steering wheel, observe the vehicle's deviation from its driving state, record the target vehicle's TTT (Travel Time), and repeat the test 5-10 times.

[0045] After activating the target vehicle drag compensation function, maintain the vehicle in a straight line on the center line of the lane for 5 seconds. Keep the vehicle in a straight line and record the target vehicle TTD. Repeat the test 5-10 times.

[0046] Determine whether the target vehicle's TTT and TTD meet the requirements;

[0047] If so, the set long-term rack force learning speed L1 and short-term rack force learning speed S1 meet the requirements. The rack force learning speed L1 and short-term rack force learning speed S1 are used for long-term and short-term rack force learning under high-speed conditions of the target vehicle.

[0048] If not, then modify the set long-term rack force learning speed L1 and short-term rack force learning speed S1.

[0049] A further approach is that if the driver of the target vehicle maintains the vehicle's straight-line movement with a hand force TTT ≤ 0.5 Nm, and the time from when the driver releases the hand to when the vehicle shifts 1 m laterally, TTD > 10 s, then the target vehicle's TTT and TTD meet the requirements.

[0050] A further solution is that whether the target vehicle meets the activation conditions for the pull compensation function specifically includes:

[0051] The target vehicle's speed is: 30kph ≤ speed ≤ 160kph;

[0052] The driver's hand strength in the target vehicle is: 0.1 Nm ≤ |driver's hand strength| ≤ 2 Nm;

[0053] The longitudinal acceleration of the target vehicle is: -1 m / s² 2 Longitudinal acceleration ≤ 1 m / s² 2 ;

[0054] The yaw rate of the target vehicle is: 0° / s < |yaw rate| ≤ 1° / s°;

[0055] The steering wheel angle of the target vehicle is: 0° < |steering wheel angle| ≤ 5°.

[0056] Understandably, setting the driver's hand force of the target vehicle to greater than or equal to 0.1 Nm ensures that the drag compensation function can still be activated when the driver's hands leave the steering wheel; setting the driver's hand force of the target vehicle to less than or equal to 2 Nm ensures that the drag compensation function will not be activated when the target vehicle is turning or changing lanes; similarly, setting the steering wheel angle to -5° to 5° further avoids activating the drag compensation function when the target vehicle is turning or changing lanes.

[0057] According to a second aspect of the present invention, a pull compensation system for solving vehicle veergence is provided, specifically comprising:

[0058] The first judgment module is used to determine whether the target vehicle meets the activation conditions of the pull compensation function.

[0059] The learning module, when the target vehicle meets the activation conditions of the pull compensation function, is used to obtain the target compensation rack force of the target vehicle by converting the difference between the current driver's hand force and the preset target hand force through mechanical relationship conversion. At the same time, it performs long-term and short-term rack force learning to obtain long-term learning rack force and short-term learning rack force. The long-term learning rack force and short-term learning rack force are used to learn the target compensation rack force.

[0060] The first calculation module is used to superimpose the rack force learned over a long period of time and the rack force learned over a short period of time to obtain the compensation rack force. The compensation rack force is converted through mechanical relationship transformation to calculate the compensation torque of the first motor.

[0061] The second judgment module, when the target vehicle meets the activation conditions of the pull compensation function, is used to judge whether the target vehicle's speed, steering wheel angle, longitudinal acceleration, yaw rate and driver's hand force are normal and effectively issued.

[0062] The second calculation module, when the target vehicle's speed, steering wheel angle, longitudinal acceleration, yaw rate, and driver's hand force are normal and effectively applied, is used to stop the learning of rack force for both long and short periods, and to compensate for the rack force by maintaining it at the long-term learned rack force of the previous moment; it then performs a mechanical relationship transformation on the long-term learned rack force of the previous moment to calculate the compensation torque of the second motor.

[0063] The third calculation module is used to stop outputting the rack force when the target vehicle's speed, steering wheel angle, longitudinal acceleration, yaw rate, and driver's hand force are not generated normally and effectively, and the motor compensation torque drops to zero.

[0064] The compensation function activation condition comprises a vehicle speed, a steering wheel angle, a longitudinal acceleration, a yaw rate and a driver hand force of the target vehicle, and the target vehicle is straight driving under the side wind and road camber conditions when the vehicle speed, the steering wheel angle, the longitudinal acceleration, the yaw rate and the driver hand force are all within preset value ranges.

[0065] According to a third aspect of the present application, a storage medium is provided, having stored thereon a computer program which, when executed by a processor, implements the steps of the method as described above.

[0066] According to a fourth aspect of the present application, a vehicle is provided, comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the steps of the method as described above when executing the program.

[0067] Compared with the prior art, the present application has the beneficial effects that: by setting the pull compensation function activation condition as the vehicle speed, the steering wheel angle, the longitudinal acceleration, the yaw rate and the driver hand force of the target vehicle being within preset value ranges, the target vehicle is straight driving under the side wind and road camber conditions while learning the rack force for long and short time simultaneously, the gradient of the rack force learning for long and short time is large, the learning is fast, the vehicle running deviation caused by the vehicle itself suspension and the like can be compensated, and the vehicle running deviation caused by the road camber or long time side wind can also be compensated; the rack force learning for long and short time is stopped when the vehicle is turning or changing lanes, the compensation rack force is maintained at the last moment of the long time learning rack force, the compensation rack force can reduce the hand force and eliminate the driver fatigue, and the large compensation rack force caused by the continuous learning of the rack force when turning, especially S-turning, is avoided, so that the large compensation rack force in the straight section after the turning or the reverse direction turning section can be eliminated, and the obvious reverse direction pulling force can be avoided to cause the bad hand feeling performance. BRIEF DESCRIPTION OF DRAWINGS

[0068] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0069] Figure 1 Schematic diagram of uniform speed deviation of the present application;

[0070] Figure 2The force analysis schematic diagram of the vehicle straight driving on the road camber pavement is provided for the present application.

[0071] Figure 3 The flow schematic diagram of the method provided by the first embodiment of the present application is shown.

[0072] Figure 4 The system structure flow chart provided by the second embodiment of the present application is shown. DETAILED DESCRIPTION

[0073] In order to make the objects, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described in detail below with reference to the drawings.

[0074] It should be noted that when an element is referred to as being "fixed" to another element, it can be directly on the other element or there can be an intervening element. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements can be present.

[0075] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0076] Running deviation is a common problem in vehicle development stage and after-sales maintenance, which refers to the phenomenon that the vehicle automatically deviates to one side when driving straight, and is generally divided into uniform speed deviation and acceleration deviation. Acceleration deviation is mainly caused by uneven power transmission system. Uniform speed deviation mainly shows that: Drift (deviation) is that the vehicle driving straight will deviate to one side if there is deviation after releasing the steering wheel; Pull (pull) is that a certain force must be applied to the steering wheel to keep the vehicle driving straight, as shown in the following Figure 1 The drift and pull schematic diagram of uniform speed deviation, under normal circumstances, the more serious the vehicle deviation, the greater the drift and pull, and in the long-term driving process, it will make the driver driving fatigue, and further affect the driving safety.

[0077] The running deviation of uniform speed is usually caused by two factors, i.e., the vehicle itself and external environment, wherein the vehicle factors include unreasonable four-wheel positioning parameter setting or unreasonable debugging, suspension system torque decay, left and right height difference, left and right tire taper out-of-tolerance, improper PRAT value selection, tire pressure difference, steering system friction, etc.; and the external environment factors include road camber and crosswind, etc. Generally, the public road design is high in the middle and low on both sides (for two-way lanes), which is designed to facilitate road drainage and reduce road water accumulation. According to the force analysis, the vehicle is subjected to the gravity component in the low side direction when running on such a road, as shown in the following figure: Figure 2 When the vehicle runs straight on the cambered road surface, the force analysis causes the vehicle to deviate to the low side of the road surface, and after the driver's hand leaves the steering wheel, the vehicle cannot guarantee straight running, resulting in the vehicle running deviation to the low side of the road surface.

[0078] The electric power steering system is based on the traditional mechanical column or mechanical steering gear, and increases a driving motor auxiliary force mechanism, which is composed of a motor, a control unit ECU and a sensor unit. The control unit ECU collects the engine speed signal and the vehicle speed signal, and collects the angle signal (steering wheel rotation angle) and the driver torque signal (driver hand force) collected by the angle sensor and the driver torque sensor of the electric power steering system, so as to realize the auxiliary driving of the driver for the steering control of the vehicle.

[0079] The pull compensation function strategy is that the electric power steering control unit ECU monitors the vehicle speed, longitudinal acceleration and yaw rate signals on the vehicle bus and the steering wheel rotation angle and driver hand force signals monitored by the electric power steering sensor, and when the monitoring conditions meet the set threshold value, the pull compensation starts to learn the rack force. The rack force learned is converted through a mechanical relationship, and the motor torque value that needs to be compensated by the motor is calculated. The final motor torque value T is output after the motor compensation torque value is superimposed on the original output torque value of the motor.

[0080] Embodiment 1

[0081] Please refer to Figure 3 The present application provides a kind of solution vehicle running deviation pull compensation method, specifically includes the following steps:

[0082] Step S1, judge whether the target vehicle meets the pull compensation function activation condition;

[0083] The compensation function activation condition includes that the vehicle speed, steering wheel rotation angle, longitudinal acceleration, yaw rate and driver hand force of the target vehicle are all in the preset numerical range, and the target vehicle runs straight in the crosswind and camber working condition when the vehicle speed, steering wheel rotation angle, longitudinal acceleration, yaw rate and driver hand force of the target vehicle are all in the preset numerical range.

[0084] In the embodiment, the vehicle speed requirement of the target vehicle satisfies: 30 kph≤vehicle speed≤160 kph; the driver hand force requirement of the target vehicle satisfies: 0.1 Nm≤|driver hand force|≤2 Nm, the driver hand force is positive when the steering wheel turns left, and the driver hand force is negative when the steering wheel turns right; the longitudinal acceleration requirement of the target vehicle satisfies: -1 m / s 2 ≤longitudinal acceleration≤1 m / s 2 ; the yaw angular velocity requirement of the target vehicle satisfies: 0° / s<|yaw angular velocity|≤1° / s; and the steering wheel angle requirement of the target vehicle satisfies: 0°<|steering wheel angle|≤5°. The driver hand force of the target vehicle is set to be greater than or equal to 0.1 Nm, so that the pull compensation function can still be activated when the driver hand leaves the steering wheel; the driver hand force of the target vehicle is set to be less than or equal to 2 Nm, so that the pull compensation function is not activated when the target vehicle turns or changes lanes; similarly, 0°<|steering wheel angle|≤5°, which further avoids activating the pull compensation function when the target vehicle turns or changes lanes.

[0085] In step S2, if yes, the target compensation rack force of the target vehicle is obtained by converting the difference between the current target vehicle driver hand force and the preset target hand force through a mechanical relationship, and long-time and short-time rack forces are learned to obtain a long-time learning rack force and a short-time learning rack force, which are used for learning to the target compensation rack force, and if no, step S4 is performed.

[0086] The increase value of the target compensation rack force is calculated according to the following formula:

[0087]

[0088] : the increase value of the target compensation rack force, unit KN;

[0089] η: system transmission efficiency, usually 0.93;

[0090] T 当前 : the current target vehicle driver hand force, unit Nm;

[0091] T 目标 : the preset target hand force, unit Nm;

[0092] C: the steering gear and rack line angle transmission ratio, unit mm / rev.

[0093] In the embodiment, the preset target hand force is set as ±0.5 Nm, wherein + corresponds to the left turning of the steering wheel, and - corresponds to the right turning of the steering wheel, wherein 0.5 Nm is the minimum torque corresponding to the ability of the general vehicle to keep straight driving when the driver's hand leaves the steering wheel, and therefore the preset target hand force is set as ±0.5 Nm, on the one hand, when the pulling compensation function is activated, the hand force of the driver when maintaining the straight driving of the vehicle can be reduced to the maximum, and on the other hand, when the driver's hand leaves the steering wheel, the compensated rack force can ensure that the vehicle keeps straight driving, and for different vehicle models, the corresponding preset target hand force setting value can be selected.

[0094] Specifically, the steps of simultaneously learning the long-time rack force and the short-time rack force specifically include:

[0095] calibrating the long-time rack force learning speed L1 and the short-time rack force learning speed S1;

[0096] obtaining the long-time rack force f1 by time integration according to the long-time rack force learning speed L1, when the driver's hand force is greater than the preset target hand force and the steering wheel is turned left or the driver's hand force is less than the preset target hand force and the steering wheel is turned right, when the driver's hand force is less than the preset target hand force and the steering wheel is turned left or the driver's hand force is greater than the preset target hand force and the steering wheel is turned right, ;

[0097] obtaining the short-time rack force f2 by time integration according to the short-time rack force learning speed S1, when the driver's hand force is greater than the preset target hand force and the steering wheel is turned left or the driver's hand force is less than the preset target hand force and the steering wheel is turned right, when the driver's hand force is less than the preset target hand force and the steering wheel is turned left or the driver's hand force is greater than the preset target hand force and the steering wheel is turned right, ;

[0098] wherein S1=k*L1, k is a constant greater than 1, in the embodiment, k=5, the units of L1 and S1 are KN / s, the units of f1 and f2 are KN, f 10 is the long-time rack force corresponding to the previous moment, f 20 is the short-time rack force corresponding to the previous moment, when the pulling compensation function activation condition is met, f 10 and f 20 are initialized as 0.

[0099] For example, but not limited to, when the current driver hand force is monitored to be 1.5 Nm, the preset target hand force is 0.5 Nm, and the target vehicle meets the activation condition of the pulling compensation function, then the long-time and short-time rack force learning is simultaneously performed, and the driver hand force is compensated to 0.5 Nm by using the long-time rack force learning speed L1 and the short-time rack force learning speed S1, respectively, and the additional 1 Nm is provided by the motor compensation torque converted from the long-time and short-time learned rack force. When the actual driver hand force of the steering wheel changes to 1.6 Nm due to the change of the target vehicle caused by its own reasons and external reasons (at this time, the sensor monitors that the current driver hand force is 0.6 Nm), the long-time and short-time rack force learning is performed based on 1 Nm, and the driver hand force is again compensated to 0.5 Nm, and the additional 1.1 Nm is provided by the motor compensation torque converted from the long-time and short-time learned rack force.

[0100] Step S3, superimposing the long-time learned rack force and the short-time learned rack force to obtain a compensation rack force, and converting the compensation rack force through a mechanical relationship to calculate a first motor compensation torque;

[0101] Specifically, ;

[0102]

[0103] T1: first motor compensation torque value, unit Nm;

[0104] f: sum of long-time and short-time learned rack force (compensation rack force), unit KN;

[0105] C: angle transmission ratio of steering gear and rack line, unit mm / rev;

[0106] η: system transmission efficiency, usually 0.93;

[0107] N: reduction ratio of worm gear.

[0108] Step S4, judging whether the speed, steering wheel angle, longitudinal acceleration, yaw rate and driver hand force of the target vehicle are normal and valid; if yes, executing step S5, if not, executing step S6;

[0109] It should be noted that when it is monitored that the speed signal of the target vehicle has no frame loss or frame loss, and the effective bit of the output value is 1, it is judged that the speed of the target vehicle is normal and valid; by analogy, when it is monitored that the steering wheel angle, longitudinal acceleration, yaw rate and driver hand force signals of the target vehicle have no frame loss or frame loss, and the effective bit of the output value is 1, it is judged that the steering wheel angle, longitudinal acceleration, yaw rate and driver hand force signals of the target vehicle are normal and valid.

[0110] Step S5, if yes, stop the long time and short time rack force learning, the compensation rack force remains the last time long time learning rack force; the last time long time learning rack force is converted by mechanical relationship, and the second motor compensation torque is calculated.

[0111] Specifically, when the target vehicle speed, the driver hand force, the steering wheel angle and the yaw rate are normal and effectively issued, and the pull compensation function activation condition is not met, the target vehicle is often turning or changing lanes, so the long time and short time rack force learning is stopped, and the compensation rack force is maintained as the last time long time learning rack force without change, which can not only provide compensation rack force to reduce the hand force and eliminate the driver's fatigue, but also avoid excessive compensation rack force due to continuous learning of rack force when turning, especially S-bending, so as to eliminate the excessive compensation rack force when turning straight or turning in the opposite direction, and provide obvious opposite direction pulling force to cause bad hand feeling.

[0112] It can be understood that, since the long time learning speed is less than the short time learning speed, the long time learning rack force is also less than the short time learning rack force, so the compensation rack force is maintained as the last time long time learning rack force instead of the last time short time rack force, which can prevent the uncontrollable PDC (pull compensation) torque when the target vehicle is turning straight or turning in the opposite direction, and avoid providing obvious opposite direction pulling force to cause bad hand feeling.

[0113] It should be noted that after the whole vehicle is powered off, the long time learning rack force will not be erased, and the short time learning rack force will be erased, so that the target vehicle can still provide long time learning rack force for compensation at the start stage of the next ignition cycle when the target vehicle speed is less than 30 kph.

[0114] Step S6, stop outputting the compensation rack force, and the motor compensation torque is reduced to zero.

[0115] It should be noted that when the signals of the target vehicle speed, the driver hand force, the steering wheel angle and the yaw rate are not normal or not effectively issued, the lateral attitude of the target vehicle is not clear, the compensation rack force is stopped to be output, and the motor compensation torque is reduced to zero to avoid causing safety accidents.

[0116] In step S2, the steps of calibrating the long time rack force learning speed L1 and the short time rack force learning speed S1 include:

[0117] Step S201, control the target vehicle to drive on a 2% slope dry road surface, and the tire pressure is calibrated according to the design state.

[0118] Step S202, accelerate the target vehicle speed to 40kph;

[0119] Step S203, set the long time rack force learning speed L1 and the short time rack force learning speed S1, and set the preset target hand force, in the calibration process, the preset target hand force can be set to 0Nm;

[0120] Step S204, after activating the target vehicle pulling compensation function, maintain the vehicle straight driving on the center line of the lane for 5s,

[0121] Step S205, release the steering wheel, observe the vehicle deviation driving state, record the target vehicle TTD, repeat the test 5-10 times;

[0122] Step S206, after activating the target vehicle pulling compensation function, maintain the vehicle straight driving on the center line of the lane for 5s, keep the vehicle straight driving, record the target vehicle TTT, repeat the test 5-10 times;

[0123] Step S207, determine whether the TTT and TTD of the target vehicle meet the requirements;

[0124] Step S208, if yes, the set long time rack force learning speed L1 and short time rack force learning speed S1 meet the requirements, the rack force learning speed L1 and short time rack force learning speed S1 are used for long time and short time rack force learning of the target vehicle under low speed working condition;

[0125] Step S209, if not, modify the set long time rack force learning speed L1 and short time rack force learning speed S1.

[0126] Step S210, accelerate the target vehicle speed to 80kph, repeat the above steps S203~S209, obtain the rack force learning speed L1 and short time rack force learning speed S1 of the target vehicle under high speed working condition, wherein in the embodiment, the target vehicle low speed working condition refers to the target vehicle speed≤50kph, and the target high speed working condition refers to the target vehicle speed>50kph.

[0127] In the embodiment, when the average hand force TTT of the driver of the target vehicle maintaining the vehicle straight driving≤0.5Nm, and the time TTD from the driver's hand off to the vehicle lateral deviation 1m>10s, the TTT and TTD of the target vehicle meet the requirements.

[0128] In summary, by setting the pull compensation function activation condition as the target vehicle speed, steering wheel angle, longitudinal acceleration, yaw rate and driver hand force in the preset value range, the target vehicle can simultaneously learn the rack force for a long time and a short time in the crosswind and road camber conditions, the gradient of the long-time and short-time rack force learning is large, the learning is fast, the vehicle running deviation caused by the vehicle suspension and the like can be compensated, and the vehicle running deviation caused by the road camber or long-time crosswind can be compensated; the long-time and short-time rack force learning can reduce the driver's hand force when maintaining the vehicle straight, and the compensated rack force can improve the vehicle's ability to maintain straight driving when the driver's hand is away from the steering wheel; when the vehicle turns or changes lanes, the long-time and short-time rack force learning is stopped, and the compensation rack force is maintained at the last moment of long-time learning rack force, which can provide compensation rack force to reduce the hand force and eliminate the driver's fatigue, and can avoid excessive compensation rack force caused by continuous learning of the rack force when turning, especially in S-bend, so as to eliminate the obvious reverse pulling force caused by excessive compensation rack force when turning in the straight lane or the reverse direction lane, and to provide obvious reverse pulling force to cause bad hand feeling.

[0129] Embodiment 2

[0130] Please refer to Figure 4 The present application provides a kind of vehicle running deviation solution of pulling compensation system, specifically includes:

[0131] First judging module, for judging whether target vehicle meets the pull compensation function activation condition;

[0132] Learning module, when target vehicle meets the pull compensation function activation condition, for obtaining the target compensation rack force of target vehicle according to the difference between the current target vehicle driver hand force and preset target hand force, while learning long-time and short-time rack force by mechanics relationship conversion, to obtain long-time learning rack force and short-time learning rack force, the long-time learning rack force and short-time learning rack force are used to learn to the target compensation rack force;

[0133] First calculation module, for superimposing long-time learning rack force and short-time learning rack force to obtain compensation rack force, compensation rack force is converted by mechanics relationship, and first motor compensation torque is calculated;

[0134] Second judging module, when target vehicle meets the pull compensation function activation condition, for judging whether the speed of target vehicle, steering wheel angle, longitudinal acceleration, yaw rate and driver hand force are normal and effective;

[0135] The second calculation module is configured to stop the learning of the long-time rack force and the short-time rack force when the vehicle speed, the steering wheel angle, the longitudinal acceleration, the yaw rate and the driver's hand force of the target vehicle are normal and effective, and to keep the compensation rack force as the long-time learning rack force of the previous moment; the second motor compensation torque is calculated by converting the mechanical relationship of the long-time learning rack force of the previous moment.

[0136] The third calculation module is configured to no longer output the compensation rack force and to reduce the motor compensation torque to zero when the vehicle speed, the steering wheel angle, the longitudinal acceleration, the yaw rate and the driver's hand force of the target vehicle are not normal and effective.

[0137] The compensation function activation condition includes that the vehicle speed, the steering wheel angle, the longitudinal acceleration, the yaw rate and the driver's hand force of the target vehicle are all within a preset value range, and the target vehicle is straight driving under the side wind and road camber working conditions.

[0138] Further, the first learning module is specifically configured to:

[0139] calibrate the long-time rack force learning speed L1 and the short-time rack force learning speed S1;

[0140] obtain the long-time rack force f1 by time integration according to the long-time rack force learning speed L1, when the driver's hand force is greater than a preset target hand force and the steering wheel turns left or the driver's hand force is less than the preset target hand force and the steering wheel turns right, when the driver's hand force is less than the preset target hand force and the steering wheel turns left or the driver's hand force is greater than the preset target hand force and the steering wheel turns right, ;

[0141] obtain the short-time rack force f2 by time integration according to the short-time rack force learning speed S1, when the driver's hand force is greater than a preset target hand force and the steering wheel turns left or the driver's hand force is less than the preset target hand force and the steering wheel turns right, when the driver's hand force is less than the preset target hand force and the steering wheel turns left or the driver's hand force is greater than the preset target hand force and the steering wheel turns right, ;

[0142] wherein S1=k*L1, k is a constant greater than 1, the units of L1 and S1 are KN / s, the units of f1 and f2 are KN, and f 10 is the long-time rack force corresponding to the previous moment, f 20 is the short-time rack force corresponding to the previous moment.

[0143] Further, calibrating the long-time rack force learning speed L1 and the short-time rack force learning speed S1 specifically includes:

[0144] Control the target vehicle to drive straight on a 2% slope dry road surface, and the tire pressure is calibrated according to the design state;

[0145] Accelerate the target vehicle to 40kph;

[0146] Set the long-time rack force learning speed L1 and the short-time rack force learning speed S1, and set the preset target hand force, and in the calibration process, the preset target hand force can be set to 0Nm;

[0147] After activating the target vehicle pulling compensation function, maintain the vehicle to drive straight on the center line of the lane for 5s,

[0148] Loosen the steering wheel, observe the vehicle deviation driving state, record the target vehicle TTD, and repeat the test 5-10 times;

[0149] After activating the target vehicle pulling compensation function, maintain the vehicle to drive straight on the center line of the lane for 5s, keep the vehicle driving straight, record the target vehicle TTT, and repeat the test 5-10 times;

[0150] Determine whether the TTT and TTD of the target vehicle meet the requirements;

[0151] If yes, the set long-time rack force learning speed L1 and the short-time rack force learning speed S1 meet the requirements, and the rack force learning speed L1 and the short-time rack force learning speed S1 are used for long-time and short-time rack force learning of the target vehicle in low-speed working conditions;

[0152] If not, modify the set long-time rack force learning speed L1 and the short-time rack force learning speed S1.

[0153] Accelerate the target vehicle to 80kph, repeat the above steps, and obtain the rack force learning speed L1 and the short-time rack force learning speed S1 of the target vehicle in high-speed working conditions, wherein the target low-speed working condition refers to the target vehicle speed ≤50kph, and the target high-speed working condition refers to the target vehicle speed >50kph.

[0154] Embodiment 3

[0155] A storage medium having a computer program stored thereon, characterized in that the program is executed by a processor to implement the steps of the method of embodiment 1.

[0156] Embodiment 4

[0157] A vehicle comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor implements the steps of the method of embodiment 1 when executing the program.

[0158] In the description of the application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used for the purpose of facilitating the description of the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application.

[0159] In the description of the application, the description of the terms "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the application. In this specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example.

[0160] It is obvious that the described embodiments are only a part of the embodiments of the application, not all the embodiments. In this paper, "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the application. The phrase appears at various places in the specification is not necessarily the same embodiment, nor is it independent or alternative to other embodiments or alternative embodiments. Those skilled in the art can understand that the embodiments described herein can be combined with other embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0161] Although the embodiments of the application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirit of the application, and the scope of the application is defined by the claims and their equivalents.

Claims

1. A method for solving the pull compensation of vehicle running deviation, characterized in that, Specifically comprising: determine whether the target vehicle meets the pull compensation function activation condition; if yes, according to the difference between the current target vehicle driver hand force and the preset target hand force, the target compensation rack force of the target vehicle is obtained through mechanical relationship conversion; At the same time, long time and short time rack force learning is carried out to obtain long time learning rack force and short time learning rack force, which are used for learning to achieve the target compensation rack force, including: calibrate long time rack force learning speed L1 and short time rack force learning speed S1; a long-time learning rack force fl is obtained by time integration according to a long-time rack force learning speed L1, when the driver hand force is greater than a preset target hand force and the steering wheel turns left or the driver hand force is less than the preset target hand force and the steering wheel turns right, ; when the driver hand force is less than the preset target hand force and the steering wheel turns left or the driver hand force is greater than the preset target hand force and the steering wheel turns right, ; The short-time rack force f2 is obtained by time integration according to the short-time rack force learning speed S1, when the driver hand force is greater than the preset target hand force and the steering wheel turns left or the driver hand force is less than the preset target hand force and the steering wheel turns right, ; when the driver hand force is less than the preset target hand force and the steering wheel turns left or the driver hand force is greater than the preset target hand force and the steering wheel turns right, ; where S1 = k*L1, k is a constant greater than 1, L1 and S1 are in units of KN / s, f1 and f2 are in units of KN, f 10 is the long time learned rack force corresponding to the previous time, f 20 is the short time learned rack force corresponding to the previous time. superimpose the long time learning rack force and the short time learning rack force to achieve the target compensation rack force, which is converted through mechanical relationship to calculate the first motor compensation torque; if no, determine whether the target vehicle speed, steering wheel angle, longitudinal acceleration, yaw rate and driver hand force are normal and effective; when the target vehicle speed, steering wheel angle, longitudinal acceleration, yaw rate and driver hand force are normal and effective, stop the learning of long time and short time rack force, and the compensation rack force remains the long time learning rack force at the last moment; mechanical relationship conversion is carried out on the long time learning rack force at the last moment to calculate the second motor compensation torque; when the target vehicle speed, steering wheel angle, longitudinal acceleration, yaw rate and driver hand force are not normal and not effectively issued, stop outputting the compensation rack force, and the motor compensation torque is reduced to zero; wherein, the compensation function activation condition includes that the target vehicle speed, steering wheel angle, longitudinal acceleration, yaw rate and driver hand force are all within the preset value range, and the target vehicle is straight under the side wind and road arch working condition.

2. The method according to claim 1, wherein the method is characterized by, The step of superimposing the long time learning rack force and the short time learning rack force to achieve the target compensation rack force, which is converted through mechanical relationship to calculate the first motor compensation torque, specifically includes: ； t1: the first motor compensation torque value, unit Nm; f: actual compensation rack force, i.e. the actual compensation rack force is to reach the target compensation rack force in KN; : Assisted gear and rack linear angle transmission ratio, unit mm / rev; η: system transmission efficiency, 0.93; N: reduction ratio of worm gear.

3. The method of claim 1, wherein the method further comprises: determining a yaw rate of the vehicle; and determining a yaw rate error based on the yaw rate and the yaw rate command. The step of calibrating long time rack force learning speed L1 and short time rack force learning speed S1 specifically includes: control the target vehicle to drive straight on the 2% slope dry road surface, and calibrate the tire pressure according to the design state; accelerate the target vehicle speed to 40kph; set the long time rack force learning speed L1 and the short time rack force learning speed S1; after activating the target vehicle pull compensation function, maintain the vehicle to drive straight on the center line of the lane for 5s, release the steering wheel, observe the vehicle deviation driving state, record the target vehicle deviation time TTD, and repeat the test 5-10 times; after activating the target vehicle pull compensation function, maintain the vehicle to drive straight on the center line of the lane for 5s, keep the vehicle to drive straight, record the target vehicle hand force TTT, and repeat the test 5-10 times; determine whether the target vehicle hand force TTT and deviation time TTD meet the requirements; If yes, the set long-time rack force learning speed L1 and short-time rack force learning speed S1 meet the requirements, which are used for long-time and short-time rack force learning of the target vehicle under low-speed working condition; If no, the set long-time rack force learning speed L1 and short-time rack force learning speed S1 are modified.

4. The method of claim 1, wherein the method further comprises: determining a yaw rate of the vehicle; and determining a yaw rate error based on the yaw rate and the yaw rate command. The steps of calibrating the long-time rack force learning speed L1 and short-time rack force learning speed S1 specifically include: The target vehicle is controlled to drive straight on a 2% slope dry road surface, and the tire pressure is calibrated according to the design state; The speed of the target vehicle is accelerated to 80 kph; The long-time rack force learning speed L1 and short-time rack force learning speed S1 are set; After the pull compensation function of the target vehicle is activated, the vehicle is maintained to drive straight on the center line of the lane for 5 s, The steering wheel is released, the vehicle deviation driving state is observed, the deviation time TTD of the target vehicle is recorded, and the test is repeated 5-10 times; After the pull compensation function of the target vehicle is activated, the vehicle is maintained to drive straight on the center line of the lane for 5 s, the vehicle is maintained to drive straight, the hand force TTT of the target vehicle is recorded, and the test is repeated 5-10 times; It is judged whether the hand force TTT and the deviation time TTD of the target vehicle meet the requirements; If yes, the set long-time rack force learning speed L1 and short-time rack force learning speed S1 meet the requirements, which are used for long-time and short-time rack force learning of the target vehicle under high-speed working condition; If no, the set long-time rack force learning speed L1 and short-time rack force learning speed S1 are modified.

5. The pull compensation method for solving vehicle driving deviation according to claim 3 or 4, characterized in that: When the hand force TTT of the target vehicle is maintained by the driver of the target vehicle and the hand force TTT is less than or equal to 0.5 Nm, and the time TTD from when the driver of the target vehicle releases the hand to when the vehicle deviates laterally by 1 m is greater than 10 s, the hand force TTT and the deviation time TTD of the target vehicle meet the requirements.

6. The method of claim 1, wherein the method further comprises: determining a yaw rate of the vehicle; and determining a yaw rate error based on the yaw rate and the yaw rate command. Specifically, whether the target vehicle meets the pull compensation function activation condition includes: The speed of the target vehicle is 30 kph≤speed≤160 kph; The hand force of the driver of the target vehicle is 0.1 Nm≤|driver hand force|≤2 Nm; The longitudinal acceleration of the target vehicle is -1 m / s2≤longitudinal acceleration≤1 m / s2; The yaw angular velocity of the target vehicle is 0° / s<|yaw angular velocity|≤1° / s°; The steering wheel angle of the target vehicle is 0°<|steering wheel angle|≤5°.

7. A drag compensation system for solving vehicle veergence, characterized in that, Specifically, it includes: A first judgment module is configured to judge whether the target vehicle meets the pull compensation function activation condition; The learning module is configured to, when the target vehicle meets the pull compensation function activation condition, obtain a target compensation rack force of the target vehicle according to a difference between a current driver hand force of the target vehicle and a preset target hand force, and through a mechanical relationship conversion, and simultaneously learn a long-time rack force and a short-time rack force to obtain a long-time learning rack force and a short-time learning rack force, the long-time learning rack force and the short-time learning rack force being used for learning to achieve the target compensation rack force, and the learning includes: calibrating a long-time rack force learning speed L1 and a short-time rack force learning speed S1; obtaining the long-time learning rack force f1 through time integration according to the long-time rack force learning speed L1, when the driver hand force is greater than the preset target hand force and the steering wheel is turned left or the driver hand force is less than the preset target hand force and the steering wheel is turned right, ; obtaining the long-time learning rack force f1 through time integration according to the long-time rack force learning speed L1, when the driver hand force is greater than the preset target hand force and the steering wheel is turned left or the driver hand force is less than the preset target hand force and the steering wheel is turned right, ; obtaining the short-time learning rack force f2 through time integration according to the short-time rack force learning speed S1, when the driver hand force is greater than the preset target hand force and the steering wheel is turned left or the driver hand force is less than the preset target hand force and the steering wheel is turned right, ; obtaining the short-time learning rack force f2 through time integration according to the short-time rack force learning speed S1, when the driver hand force is greater than the preset target hand force and the steering wheel is turned left or the driver hand force is less than the preset target hand force and the steering wheel is turned right, ; wherein S1=k*L1, k is a constant greater than 1, the units of L1 and S1 are KN / s, the units of f1 and f2 are KN, f 10 is the long-time learning rack force corresponding to a previous moment, and f 20 is the short-time learning rack force corresponding to a previous moment. A first calculation module is configured to superimpose the long-time learning rack force and the short-time learning rack force to obtain the target compensation rack force, and the target compensation rack force is converted into a first motor compensation torque through a mechanical relationship; A second judgment module is configured to judge whether the speed, the steering wheel angle, the longitudinal acceleration, the yaw angular velocity and the driver hand force of the target vehicle are normal and effective when the target vehicle meets the pull compensation function activation condition. The second calculation module is configured to stop the learning of the long-time and short-time rack forces when the vehicle speed, the steering wheel angle, the longitudinal acceleration, the yaw rate and the driver's hand force of the target vehicle are normal and effectively issued, to keep the compensation rack force as the long-time learned rack force at the previous time, and to convert the long-time learned rack force at the previous time through a mechanical relationship to obtain a second motor compensation torque; The third calculation module is configured to stop the output of the compensation rack force and to reduce the motor compensation torque to zero when the vehicle speed, the steering wheel angle, the longitudinal acceleration, the yaw rate and the driver's hand force of the target vehicle are abnormal and not effectively issued. The compensation function activation condition includes that the vehicle speed, the steering wheel angle, the longitudinal acceleration, the yaw rate and the driver's hand force of the target vehicle are all within a preset value range, and the target vehicle is straightly driven under the side wind and road arch working conditions when the vehicle speed, the steering wheel angle, the longitudinal acceleration, the yaw rate and the driver's hand force of the target vehicle are all within the preset value range.

8. A storage medium having stored thereon a computer program, characterized in that The program is executed by the processor to implement the steps of the method of any one of claims 1 to 6.

9. A vehicle characterized by comprising: The computer program is stored in the memory and executable on the processor, and the processor implements the steps of the method of any one of claims 1 to 6 when executing the program.

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