CN-121989707-A - Quick parking method suitable for electric forklift ramp

CN121989707ACN 121989707 ACN121989707 ACN 121989707ACN-121989707-A

Abstract

The invention discloses a quick parking method suitable for an electric forklift ramp, which comprises the steps of firstly carrying out quality evaluation on motor rotating speed signals acquired by an encoder, dynamically selecting a filtering strategy, outputting a preprocessed actual speed, extracting time domain, frequency domain and model association characteristics based on the speed, a motor torque direction and a target speed, calculating confidence coefficients of different road surface working conditions through a fuzzy reasoning system, further calculating a first-stage given speed according to the target speed and a previous cycle given speed, calculating an auxiliary function given speed according to consistency judgment of the torque direction and the speed direction and the working condition confidence coefficient, generating a final given speed by utilizing a self-adaptive gain coefficient, finally carrying out closed-loop adjustment on the final given speed and the actual speed to drive a motor to execute parking, and simultaneously carrying out grading safety intervention based on the working condition confidence coefficient and the real-time vehicle speed, thereby effectively eliminating deceleration delay in the ramp parking process and improving the control rapidness and stability.

Inventors

WU CHUNYANG
CHENG XIUBO
LI FEI
YAO XIN

Assignees

河南嘉晨智能控制股份有限公司

Dates

Publication Date: 20260508
Application Date: 20260210

Claims (10)

1. The method is characterized in that the method realizes cooperative work through joint debugging and joint control of a signal preprocessing module, a working condition identification module, a speed control module and a safety supervision module, and comprises the following steps: S100, acquiring a motor rotating speed signal in real time through an encoder built in an electric forklift, and calculating to obtain an original actual speed; S200, extracting time domain features, frequency domain features and model association features based on the preprocessed actual speed, the preprocessed motor torque direction and the preprocessed target speed; s300, calculating a first-stage given speed according to the target speed and a previous cycle given speed, calculating an auxiliary function given speed based on consistency judgment of a torque direction and a speed direction and working condition confidence, calculating a given speed supplement value by using an adaptive gain coefficient, and generating a final given speed; and S400, performing closed-loop adjustment on the final given speed and the actual speed, driving the motor to execute a parking action, and simultaneously, performing hierarchical safety intervention based on the working condition confidence and the real-time vehicle speed.
2. The quick parking method for an electric forklift ramp according to claim 1, wherein the dynamically selecting filtering strategy in step S100 specifically comprises: when the signal quality comprehensive score is higher than a first quality threshold, adopting a slight low-pass filtering strategy; When the signal quality comprehensive score is lower than a second quality threshold, a two-stage series filtering strategy is started, median filtering is firstly carried out to remove abnormal values, then strong low-pass filtering is carried out, and a predicted value based on a vehicle dynamics model is introduced to carry out data fusion; the signal quality state comprises a current filtering mode and a quality grading value, and the current filtering mode and the quality grading value are transmitted to the working condition identification module in real time to serve as a judgment basis.
3. The method for rapid stopping of an electric forklift ramp according to claim 1, wherein the multi-mode condition recognition in step S200 specifically comprises: the time domain features are standard deviations of actual speeds in a preset time window; the frequency domain features are high-frequency band energy duty ratio obtained by performing frequency domain transformation on the original speed signal; The model association characteristic is the linear correlation degree of the actual speed and the motor torque; the fuzzy reasoning system takes time domain features, frequency domain features, model associated features and signal quality scores as inputs, outputs the confidence coefficient of each working condition, and the sum of the normal road surface confidence coefficient, the bumpy road surface confidence coefficient and the wet road surface confidence coefficient is a constant value; and when the confidence coefficient of the wet road surface is higher than the second confidence coefficient threshold value, judging that the working condition of the wet road surface is the working condition of the wet road surface.
4. The method for rapid stopping of an electric forklift ramp according to claim 1, wherein the specific step of calculating the adaptive given speed in step S300 comprises: S310, if the target speed is greater than the previous cycle given speed, the first stage given speed is equal to the previous cycle given speed plus the product of the acceleration rate and the control cycle, and if the target speed is less than the previous cycle given speed, the first stage given speed is equal to the previous cycle given speed minus the product of the deceleration rate and the control cycle; S320, when the torque direction is the same as the speed direction and the target speed is smaller than the first-stage given speed, if the actual speed is larger than zero, the auxiliary function given speed takes a smaller value of the actual speed and the first-stage given speed, and if the actual speed is smaller than zero, the auxiliary function given speed takes a larger value of the actual speed and the first-stage given speed; S330, the given speed supplement value is equal to the product of the adaptive gain coefficient and the difference between the given speed of the auxiliary function and the given speed of the first stage, and the final given speed is equal to the given speed of the first stage plus the given speed supplement value.
5. The method for fast stopping an electric forklift ramp according to claim 4, wherein the adaptive gain factor is smoothly adjusted in real time according to the operating condition confidence level: under normal road conditions, the self-adaptive gain coefficient is in a higher range to ensure the quick response performance; under the condition of bumpy road surface, the self-adaptive gain coefficient is in a medium range, so that the control sensitivity is reduced, and the system oscillation is avoided; under the working condition of a wet road surface, the self-adaptive gain coefficient is in a lower range so as to implement soft deceleration and prevent the wheels from slipping.
6. The quick stopping method for an electric forklift ramp according to claim 1, wherein the specific strategy of the hierarchical safety intervention in step S400 comprises: Setting a dynamic safety speed threshold, wherein the safety speed threshold under a normal road surface is in a higher range, and the safety speed threshold under a wet road surface is in a lower range; when the confidence coefficient of the wet road surface is higher than a third confidence coefficient threshold value and the actual speed is higher than a safety speed threshold value, triggering first-level intervention, and limiting a given speed supplement value within a preset proportion range of a current value; when the confidence coefficient of the wet road surface is higher than a fourth confidence coefficient threshold value and the actual speed is obviously higher than a safe speed threshold value, triggering a secondary intervention, suspending a quick parking function and sending early warning information to the instrument through a vehicle communication bus.
7. The method according to claim 1, wherein the speed closed-loop control in step S400 is performed by using an adaptive PID controller, the proportionality coefficient of which is calculated by weighting according to the confidence coefficient of each working condition, the integral coefficient of which is reduced appropriately under the condition of bumpy road, and the differential coefficient of which is reduced significantly under the condition of wet road.
8. The quick parking method for an electric forklift ramp according to claim 1, further comprising the steps of step S500, system self-learning and parameter optimization: s510, continuously recording control effect data under different road conditions, including actual speed tracking errors and intervention event frequencies; S520, optimizing a membership function and a decision rule table of the fuzzy inference system based on historical data; S530, automatically fine-tuning control parameters according to the vehicle use environment and the operation habit of a driver, and realizing personalized adaptation.
9. The quick parking method for an electric forklift ramp according to claim 1, wherein the joint adjustment and control mode is realized by a feedforward-feedback mechanism: the confidence coefficient vector output by the working condition identification module is fed forward to the speed calculation module and is used for real-time adjustment of the self-adaptive gain coefficient; the execution effect of the speed control module is fed back to the signal preprocessing module through the dynamic response of the vehicle and is used for correcting the signal quality evaluation strategy; the safety supervision module dynamically adjusts the intervention threshold according to the real-time risk level, and forms closed loop cooperation with the working condition identification module and the speed control module.
10. An electric fork truck ramp quick park control system for implementing the method of any one of claims 1 to 9, comprising: the signal acquisition and dynamic preprocessing module comprises an encoder interface and a signal processing unit; the multi-mode working condition identification module comprises a feature extractor and a fuzzy reasoning engine; an adaptive given speed calculation module comprising a speed calculator and a gain adjuster; The speed closed loop and safety supervision module comprises a PID controller and a safety logic unit; the system self-learning and parameter optimization module comprises a data recorder and a parameter optimizer; the system is integrated in a micro control unit of the electric forklift, joint debugging and joint control among all modules are realized through bus communication, and the quick parking function of the ramp can be completed without an additional sensor.

Description

Quick parking method suitable for electric forklift ramp Technical Field The invention relates to the technical field of vehicle control, in particular to a quick parking method suitable for an electric forklift ramp. Background The electric forklift is used as important in-situ logistics carrying equipment, the working environment is complex, the working conditions of ramp driving and stopping are frequently faced, the electric forklift generally adopts a speed control mode, namely, a controller determines target speed according to the depth of an accelerator, and smoothly-changed instruction rotating speed is obtained through ramp function processing, and finally speed closed-loop control is carried out. The control mode is good in performance under the flat road working condition, when the vehicle runs on a climbing slope, the command rotating speed reaches a high position after the accelerator is stepped on deeply, the actual rotating speed is possibly affected by load to be low, and when a driver loosens the accelerator, the command rotating speed slowly drops to the actual rotating speed from the high position, the vehicle lacks effective deceleration feedback, obvious deceleration delay feel is generated, and the control experience and the operation safety are affected. Aiming at the problems, the prior art mainly comprises two solutions, wherein the first solution is to uniformly adopt a fixed acceleration rate and a fixed deceleration rate to carry out the slope treatment of a given speed without distinguishing a slope from a flat ground, and the method is simple and easy to implement, but can not solve the problem of the special deceleration delay of the working condition of the slope. The second solution is to detect the road gradient by introducing a gradient sensor such as a gyroscope and dynamically correct the upper limit of the target speed according to gradient information, and the Chinese patent with the application number of CN202510878780.8 discloses a target speed limiting method related to gradient calculation, which can relieve the deceleration delay to a certain extent but increase the hardware cost, and the reliability of the sensor and the complexity of installation and maintenance become new consideration factors. Although related technologies try to improve the performance of the ramp through different ideas, in the actual running of the electric forklift, the vehicle usually works on a wet and greasy ramp, the road surface adhesion force is reduced, the driving wheel is easy to slip, under the working condition of the wet ramp, if the existing scheme is still adopted, the motor rotation speed fed back by the encoder is seriously deviated from the actual speed of the vehicle, so that the speed reduction logic based on speed comparison fails, the expected braking effect cannot be triggered in time, and potential safety hazards exist. In addition, when the electric fork lift truck works on severe sites such as mines, construction sites and the like, the road surface of a ramp is often rugged, the speed and torque signals can be greatly fluctuated and noise caused by severe jolting, and the simple logic judgment in the prior art is extremely easy to trigger by mistake under signal jump, so that the vehicle is caused to be accidentally and frequently decelerated on a fluctuated slope, and the driving experience and the working efficiency can be seriously influenced by the sense of frustration caused by deceleration. Disclosure of Invention The invention aims to provide a quick parking method suitable for an electric forklift ramp, and aims to solve the problems in the background art. In order to achieve the above purpose, the present invention provides the following technical solutions: The invention provides a quick parking method suitable for an electric forklift ramp, which realizes cooperative work through joint debugging and joint control of a signal preprocessing module, a working condition identification module, a speed control module and a safety supervision module, and comprises the following steps: S100, acquiring a motor rotating speed signal in real time through an encoder built in an electric forklift, and calculating to obtain an original actual speed; S200, extracting time domain features, frequency domain features and model association features based on the preprocessed actual speed, the preprocessed motor torque direction and the preprocessed target speed; s300, calculating a first-stage given speed according to the target speed and a previous cycle given speed, calculating an auxiliary function given speed based on consistency judgment of a torque direction and a speed direction and working condition confidence, calculating a given speed supplement value by using an adaptive gain coefficient, and generating a final given speed; and S400, performing closed-loop adjustment on the final given speed and the actual speed, driving the motor to execute a parking action, an