CN-122008878-A - Engineering vehicle walking torque distribution and driving anti-slip control method and system

CN122008878ACN 122008878 ACN122008878 ACN 122008878ACN-122008878-A

Abstract

The invention discloses a running torque distribution and driving anti-slip control method and system for an engineering vehicle, and belongs to the technical field of engineering vehicle control. The method comprises the steps of collecting vehicle pedals, gears and wheel speed signals, carrying out piecewise nonlinear re-analysis and walking pattern identification, carrying out preliminary distribution and constraint of four-wheel drive or braking energy recovery torque, generating a four-wheel initial torque request, generating an anti-skid reference tracking wheel speed based on a vehicle state, independently identifying the slip state of each wheel by comparing the actual wheel speed of each wheel with the reference wheel speed and combining with the throttle opening degree distribution, outputting an identification, calculating a torque connection pipe value based on a robust integral slip mode control algorithm with the reference wheel speed as a target when the wheels slip, and taking the torque connection pipe value and the initial torque request of the corresponding wheel as final output after the torque connection pipe value is small. The invention solves the problem that the traditional anti-skid control fails near zero speed, and realizes the self-adaptive driving anti-skid control with full working condition and high precision.

Inventors

ZHANG LEI
LI SIYANG
DING XIAOLIN

Assignees

北京理工大学

Dates

Publication Date: 20260512
Application Date: 20260413

Claims (10)

1. The engineering vehicle walking torque distribution and driving anti-skid control method is characterized by comprising the following steps of: S10, walking control, comprising the following steps: S11, acquiring an accelerator pedal opening signal, a brake pedal opening signal, a gear signal, a wheel speed signal of each wheel and a vehicle body posture signal of the vehicle; S12, performing piecewise nonlinear re-analysis on the accelerator pedal opening signal and the brake pedal opening signal to obtain an analyzed accelerator pedal opening value and brake pedal opening value, and identifying a plurality of whole vehicle running modes including driving, sliding and braking states by combining the gear signals; S13, performing preliminary distribution of four-wheel drive torque or braking energy recovery torque based on the walking mode, the vehicle state calculated by the wheel speed signal and the vehicle body posture signal and pre-stored external characteristic data of the motor, and applying torque constraint to generate a four-wheel initial torque request; S20, identifying a slip state, including: s21, generating anti-skid reference tracking wheel speeds covering positive and negative full speed domains based on the vehicle state of the S13; s22, obtaining the actual wheel speed of each wheel based on the wheel speed signal acquired in the S11, comparing the actual wheel speed with the anti-skid reference tracking wheel speed, and combining the accelerator pedal opening value analyzed in the S12 to identify whether each wheel enters a slip state or not in a distributed manner and output a slip state identifier; S30, anti-skid control, which comprises the following steps: S31, if the wheels enter the slip state according to the slip state identification in S22, starting anti-slip control for the wheels entering the slip state, taking the anti-slip reference tracking wheel speed in S21 as a tracking target, and calculating a torque take-over value of the wheels based on a robust integral slip mode control algorithm; s32, comparing the torque take-over value with the initial torque request of the corresponding wheel, and taking a smaller value as a final output torque request of the wheel; And S33, if the slip state identification indicates that all wheels do not slip, the initial torque request is directly used as a final output torque request of the corresponding wheels.
2. The method for distributing and controlling skid resistance of a traveling torque of an engineering vehicle according to claim 1, wherein the piecewise nonlinear reparse in S12 comprises: Dividing the opening value of the accelerator pedal opening signal into a first section opening interval and a second section opening interval, analyzing the first section opening interval into a value related to the slip energy recovery intensity, and analyzing the second section opening interval into a value related to the driving force request by a nonlinear mapping relation so as to obtain the analyzed accelerator pedal opening value; And carrying out nonlinear superposition analysis on the opening value of the brake pedal opening signal based on the sliding energy recovery intensity corresponding to the first section opening interval to obtain a value related to the brake energy recovery intensity, thereby obtaining the analyzed brake pedal opening value.
3. The method for distributing and controlling slip resistance of traveling torque of an engineering vehicle according to claim 1, wherein the preliminary distribution of four-wheel drive torque or braking energy recovery torque in S13 comprises: according to the identified walking mode, a driving torque distribution strategy, a sliding energy recovery torque distribution strategy or a braking energy recovery torque distribution strategy is adopted respectively; In the driving torque distribution strategy, a preliminary driving torque request is generated based on the analyzed accelerator pedal opening value, the motor external characteristic data and the direction indicated by the gear signal, a first front-rear axle load proportion is estimated based on the vehicle state by estimating axle load transfer caused by the request, and the preliminary driving torque request is distributed to front-rear axle wheels according to the estimated first front-rear axle load proportion to obtain a preliminary torque request value of each wheel; In the sliding energy recovery torque distribution strategy, a preliminary sliding energy recovery torque request is generated based on the analyzed accelerator pedal opening value, the motor external characteristic data and the whole vehicle running direction determined according to the wheel speed signal, a second front-rear axle load proportion is obtained by estimating axle load transfer caused by the request according to the vehicle state, and the preliminary sliding energy recovery torque request is distributed to front-rear axle wheels according to the estimated second front-rear axle load proportion to obtain a preliminary torque request value of each wheel; In the braking energy recovery torque distribution strategy, a preliminary braking energy recovery torque request is generated based on the analyzed opening value of the brake pedal, the external characteristic data of the motor and the whole vehicle running direction determined according to the wheel speed signal, a third front-rear axle load proportion is obtained by estimating axle load transfer caused by the request according to the vehicle state, and the preliminary braking energy recovery torque request is distributed to front-rear axle wheels according to the estimated third front-rear axle load proportion to obtain a preliminary torque request value of each wheel.
4. The method for distributing and controlling skid resistance of engineering vehicle running torque according to claim 3, wherein the applying torque constraint in S13 specifically comprises: applying a rate-of-change gradient constraint and a torque capacity constraint to the preliminary torque request value of each wheel respectively to generate the four-wheel initial torque request; The change rate gradient constraint is set in a segmented mode based on the torque value of the four-wheel initial torque request; the torque capacity constraint is determined based on the off-machine characteristic data.
5. The method for distributing and controlling the skid resistance of the engineering vehicle according to claim 1, wherein the step S21 of generating the skid resistance reference tracking wheel speed covering the positive and negative full speed ranges of the vehicle comprises the following steps: According to the gear signal, distinguishing a forward driving working condition and a reverse driving working condition; Aiming at the forward driving working condition and the reverse driving working condition respectively, constructing a piecewise linear function taking the longitudinal estimated vehicle speed of the vehicle as input, and outputting a corresponding anti-skid reference tracking wheel speed; wherein for each of the piecewise linear functions, the output value of the anti-skid reference wheel speed is maintained at a very zero value for an interval defined by a preset positive and negative vehicle speed threshold centered at a vehicle speed equal to zero.
6. The method for distributing and controlling skid resistance of engineering vehicle running torque according to claim 5, wherein step S22 is to identify whether each wheel is in skid state or not in a distributed manner, and comprises: Setting an independent state machine for each wheel, wherein the state machine at least comprises a non-skid state and a skid state; According to the difference value between the actual wheel speed of each wheel and the anti-skid reference tracking wheel speed, the duration of the difference value and whether the opening value of the accelerator pedal exceeds a preset threshold value, the state of driving each wheel is switched between the non-anti-skid state and the anti-skid state; And outputting the slip state identifier for indicating that the wheel enters the slip state when the state machine is in the non-slip state, and outputting the slip state identifier for indicating that the wheel does not enter the slip state when the state machine is in the non-slip state.
7. The method for distributing and controlling the skid resistance of the traveling torque of the engineering vehicle according to claim 1, wherein the torque take-over value of the wheel is calculated based on the robust integral sliding mode control algorithm in S31, specifically: Taking the wheel in the slip state as a controlled object to construct a rotation dynamics model; Defining a slip form surface containing an integral term of tracking errors, adopting an improved exponential approach law to design a control law, and calculating to obtain a motor torque take-over value required for inhibiting the wheel slip; the tracking error is the difference between the actual angular velocity of the wheel and the expected angular velocity, the actual angular velocity of the wheel is obtained by conversion based on the actual wheel speed of each wheel, and the expected angular velocity is obtained by conversion of the anti-skid reference tracking wheel speed.
8. An engineering vehicle running torque distribution and drive slip prevention control system for realizing the engineering vehicle running torque distribution and drive slip prevention control method according to any one of claims 1 to 7, characterized by comprising: a walking control module configured to perform the walking control step; A slip state identification module configured to perform the slip state identification step; A drive anti-slip control module configured to perform the anti-slip control step; Wherein the output end of the walking control module is connected to the first input end of the driving anti-skid control module, the output end of the slip state identification module is connected to the second input end of the driving anti-slip control module, and the output end of the driving anti-slip control module is used for outputting a final output torque request of each wheel.
9. The work vehicle travel torque distribution and drive slip control system of claim 8, wherein the slip state identification module comprises: The reference wheel speed generation unit is configured to distinguish different driving working conditions according to the gear signals, and respectively construct piecewise linear functions which take the vehicle speed as input and have a non-zero constant output interval near zero speed aiming at different working conditions so as to generate the anti-skid reference tracking wheel speed; The distributed state machine identification unit is connected with the reference wheel speed generation unit and is configured to maintain an independent state machine for each wheel, and the state machine is driven to switch by comparing the actual wheel speed of each wheel with the anti-skid reference tracking wheel speed and combining with the opening degree of an accelerator pedal so as to output the slip state identification.
10. The work vehicle travel torque distribution and drive anti-slip control system of claim 8, wherein the drive anti-slip control module comprises: The robust integral sliding mode controller is configured to calculate a torque take-over value based on a rotational dynamics model of the wheel and an improved exponential approach law by taking the anti-slip reference tracking wheel speed as a tracking target when the wheel enters a slip state; And the torque selector is connected with the walking control module and the robust integral sliding mode controller and is configured to reduce the torque take-over value and the initial torque request of the corresponding wheel as a final output torque request.

Description

Engineering vehicle walking torque distribution and driving anti-slip control method and system Technical Field The invention relates to the technical field of engineering vehicle control, in particular to an engineering vehicle walking torque distribution and driving anti-slip control method and system. Background The large-scale articulated engineering machinery vehicles, such as loaders, bulldozers and the like, are widely applied to the fields of mining, large engineering guarantee and the like. As electric drive technology has evolved, distributed electric drive configurations began to be applied to such vehicles. The configuration is provided with independent wheel driving motors at each wheel, has the advantages of quick response, high control freedom degree and the like, and is beneficial to solving the problems of high energy consumption and large emission of the traditional fuel engineering machinery. However, the articulated distributed electric drive engineering vehicle is a multi-constraint statically indeterminate system, and the vehicle states of the system are mutually coupled, so that efficient walking control, particularly reasonable distribution of the torques of all motors, becomes difficult. In addition, the vehicles usually carry out operations such as shoveling, bulldozing and the like on road surfaces with complex and changeable attachment conditions, and when partial wheel loads are severely changed and even suspended, the driving wheels are extremely easy to slip, so that the operation efficiency is seriously affected, and the tire abrasion is further increased. The existing engineering vehicle driving anti-skid control scheme has certain limitations. A scheme (patent: an electric loader driving anti-skid adjustment control method and system, publication number: CN 119283642A) mainly aims at a centralized electric driving vehicle, the anti-skid function of the electric loader driving anti-skid adjustment control method is usually activated only in a specific operation mode, and anti-skid judgment and control are carried out through the acceleration threshold value of the whole vehicle. In another scheme (patent: four-wheel steering mechanism-free distributed drive automobile anti-skid control method and device, publication number: CN 112693328A), distributed drive is considered, but the anti-skid control core is PID regulation based on fixed target slip rate. When the vehicle performs low-speed and reciprocating operation (the vehicle speed is frequently changed near zero), the slip rate calculation formula can cause control failure or generate a great error due to infinitesimal denominator when the vehicle speed approaches zero, and can not adapt to the typical working scene of engineering machinery. In addition, this type of solution lacks closed loop control based on a vehicle dynamics model and has poor adaptability to road surface adhesion and vertical load changes. Therefore, an innovative anti-skid control method and system which can adapt to the articulated distributed electric driving engineering machinery vehicle is needed, and the system is used on complex road surfaces and under all working conditions, especially in low-speed and reciprocating operation scenes, so that efficient, stable and self-adaptive vehicle control is realized. Disclosure of Invention The invention aims to provide an engineering vehicle walking torque distribution and driving anti-skid control method and system, which are used for overcoming the defects that the walking control adaptability of a hinged distributed electric driving engineering vehicle is poor and the traditional anti-skid method fails in low-speed and reciprocating operation in the prior art, and can realize full-speed domain and full-working-condition self-adaptive driving anti-skid control. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: a method for distributing and driving anti-slip control of engineering vehicle running torque comprises the following steps: S10, walking control, comprising the following steps: S11, acquiring an accelerator pedal opening signal, a brake pedal opening signal, a gear signal, a wheel speed signal of each wheel and a vehicle body posture signal of the vehicle; S12, performing piecewise nonlinear re-analysis on the accelerator pedal opening signal and the brake pedal opening signal to obtain an analyzed accelerator pedal opening value and brake pedal opening value, and identifying a plurality of whole vehicle running modes including driving, sliding and braking states by combining the gear signals; S13, performing preliminary distribution of four-wheel drive torque or braking energy recovery torque based on the walking mode, the vehicle state calculated by the wheel speed signal and the vehicle body posture signal and pre-stored external characteristic data of the motor, and applying torque constraint to generate a four-wheel initial torque request;