CN116238495A

CN116238495A - Heavy truck constant-speed cruising torque calculation method based on multi-parameter control

Info

Publication number: CN116238495A
Application number: CN202111492536.6A
Authority: CN
Inventors: 王丽萍; 王瀚州
Original assignee: Shaanxi Heavy Duty Automobile Co Ltd
Current assignee: Shaanxi Heavy Duty Automobile Co Ltd
Priority date: 2021-12-08
Filing date: 2021-12-08
Publication date: 2023-06-09

Abstract

The invention relates to the technical field of automobile cruise control, and particularly discloses a constant-speed cruise torque calculation method of a heavy truck based on multi-parameter control, wherein when a driver operates a vehicle to enter a constant-speed cruise state, a cruise torque calculation control unit calculates cruise torque in a multi-parameter control mode so as to quickly reach a target vehicle speed, and the multi-parameter comprises a vehicle speed PI regulating torque value, an acceleration PI regulating torque value, a compensation torque value generated by a vehicle weight parameter, a basic torque value and a torque value at the last moment; the cruising torque calculation control unit calculates a torque value required by the current target vehicle speed through the current vehicle condition information, so that the cruising target vehicle speed can be quickly reached, and the stability of the vehicle is maintained; the control method can be autonomously applied to cruise speed control under various vehicle conditions, does not need to manually calibrate PI parameters under special working conditions, and improves the intelligent and accurate control of the vehicle.

Description

Heavy truck constant-speed cruising torque calculation method based on multi-parameter control

Technical Field

The invention relates to the technical field of automobile cruise control, in particular to a method for calculating constant-speed cruise torque of a heavy truck based on multi-parameter control.

Background

The constant-speed cruising can enable a driver to drive the vehicle at a fixed speed without stepping on an accelerator, so that fatigue of the driver in long-distance driving is reduced to a great extent, the probability of accident occurrence of the vehicle is reduced, meanwhile, the vehicle keeps running at a constant speed all the time, and the fuel consumption can be reduced. And the self-adaptive cruising in the intelligent driving ADAS system is realized by means of constant-speed cruising.

When a driver starts cruising or carries out speed adjustment by a cruising switch, the current speed is adjusted to the cruising target speed, the control of the process directly influences driving feeling, the cruising speed control is usually realized by adopting a PI (Proportional-Integral) Proportional-Integral regulator, and the setting of PI adjustment parameters is very important. The proportion P has a large effect, so that the adjustment can be quickened, the static difference is reduced, but the stability of the system is reduced and even the system is unstable due to the overlarge proportion. The integral I is beneficial to reducing overshoot and vibration, so that the stability of the system is increased, but the static error elimination time of the system is prolonged. Therefore, the proper proportion and integral parameters can not only quickly reach the target speed, but also improve the stability of the vehicle.

In the industry, a plurality of sets of PI parameters are fixed to control the cruise speed of the vehicle, so that the cruise speed is suitable for different vehicle speed sections, when the acceleration of the vehicle speed is high, the PI parameters are unsuitable, the vehicle can be in a cruise state all the time even longer in the vehicle speed adjusting time, and when the vehicle is under different loads, different calibration parameters are required to be written for stabilizing the cruise speed, so that the universality cannot be achieved, and the self-adaption is poor. Under the normal condition, the vehicle speed is lower, the vehicle load is smaller, the vehicle demand torque is generally smaller, the vehicle speed is higher, the vehicle demand torque is larger when the load is larger, torque adjustment is carried out only through the vehicle speeds Kp and Ki, when the vehicle demand torque is smaller, kp and Ki are overlarge to cause larger cruising torque calculation, the vehicle speed exceeds the target vehicle speed when the vehicle demand torque is larger, kp and Ki are too small to cause smaller cruising torque calculation, and when the vehicle demand torque is larger, the vehicle speed is not up to come up, so that cruising driving experience is poor, meanwhile, the control is unstable, and the fuel consumption is also increased. Therefore, there is an urgent need to design a method for calculating the constant-speed cruising torque of a heavy truck based on multi-parameter control, so as to solve the problems of single constant-speed cruising control parameter and unstable vehicle speed control of the existing heavy truck.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a heavy truck constant-speed cruising torque calculation method based on multi-parameter control.

The technical scheme adopted for solving the technical problems is as follows: the constant-speed cruising torque calculation method based on multi-parameter control comprises a cruising torque calculation control unit, parameters acquired by the cruising torque calculation control unit and cruising torque output, wherein the parameters acquired by the cruising torque calculation control unit comprise a current vehicle speed, vehicle weight information, cruising target vehicle speed, cruising torque calculation enabling signals and a torque value at the last moment, a torque calculation method enabling module, a difference value calculation module, a vehicle speed PI parameter calculation module, an acceleration PI parameter calculation module and a vehicle weight state judgment module are arranged in the cruising torque calculation control unit, and vehicle speed PI adjustment torque value calculation, acceleration PI adjustment torque value calculation, vehicle weight compensation torque calculation and basic torque calculation are carried out in the cruising torque calculation control unit according to the modules;

the method specifically comprises the following steps:

s1, a driver turns on a cruise switch, and a cruise target torque calculation module is enabled after a target vehicle speed is calculated;

s2, enabling judgment of a torque calculation method: calculating a current vehicle speed difference value according to the current vehicle speed and the cruising target vehicle speed, and calculating whether the current vehicle speed difference value is in a certain interval;

acceleration value: calculating a current acceleration value by an averaging method according to the current vehicle speed value and the vehicle speed value at the last moment;

vehicle speed Kp parameter value: looking up a table according to a one-dimensional curve of the current speed to obtain a Kp value;

vehicle speed Ki parameter value: looking up the Ki value according to a one-dimensional curve of the current speed;

acceleration Kp parameter value: looking up a table according to the current acceleration one-dimensional curve to obtain a Kp value;

acceleration Ki parameter value: looking up the Ki value according to the current acceleration one-dimensional curve;

calculating the weight state: judging whether the current vehicle weight state is in one of no-load, medium-load and heavy-load according to the vehicle weight information;

s3, calculating a torque value:

vehicle speed PI adjusts torque value: the current vehicle speed Kp and Ki value input calculates a vehicle speed PI regulating torque value through a PI regulator;

acceleration PI adjusts torque value: the current acceleration Kp and Ki value are input and an acceleration PI regulating torque value is calculated through a PI regulator;

base torque value: according to the current vehicle speed one-dimensional curve, looking up a table to obtain a basic torque value;

calculating the vehicle weight compensation torque: outputting a compensation torque value according to the vehicle weight state;

torque value at last moment: acquiring a torque output value at the previous moment in real time;

s4, judging that the torque calculation method is enabled, adopting the cruise torque calculation method 1 when the torque calculation method is judged to be within a certain interval, and adopting the cruise torque calculation method 2 when the torque calculation method is judged to be outside the certain interval;

s5, outputting the cruising torque to an engine torque controller of the heavy truck, and cruising the heavy truck.

Preferably, the torque calculation method enables to select the cruise torque calculation method, if the difference between the current vehicle speed and the cruise target vehicle speed is less than or equal to the threshold value, the cruise torque calculation method 1 is selected, and otherwise, the cruise torque calculation method 2 is selected.

Preferably, the difference calculation includes calculation of a vehicle speed difference and calculation of an acceleration difference, the vehicle speed difference is calculated by calculating a current vehicle speed and a cruising target vehicle speed difference, the vehicle acceleration difference is calculated first, the vehicle acceleration is required to be calculated, the acceleration is calculated by calculating acceleration in one period by the current vehicle speed and the vehicle speed difference at the last moment, the average value of the acceleration in ten periods is accumulated, the acceleration difference is obtained by subtracting the current vehicle acceleration from an acceleration target value corresponding to a table look-up of the vehicle speed difference, the acceleration target value is increased along with the increase of the vehicle speed difference, and when the vehicle speed difference is a negative value, the acceleration target value corresponds to a negative value.

Preferably, the calculation of the vehicle speed PI parameter is to calculate Kp proportion parameters and Ki integral parameters under different vehicle speeds by collecting a current vehicle speed table, when the vehicle speed is higher, the required torque of the whole vehicle is relatively larger, when the vehicle enters the cruising vehicle speed from the current vehicle speed, in order to reach the cruising target vehicle speed faster, the driver cannot feel the reduction of the vehicle speed in the adjusting process, or the whole vehicle has the situation of traveling, the torque required to be calculated at the moment is increased, in order to achieve the purpose, when the vehicle speed is higher, the Kp parameter value and the Ki parameter value are also larger, the Kp parameter value and the Ki parameter value can be set as calibration parameters, and the proper value is formulated by calibrating and changing the actual condition of the vehicle.

Preferably, the calculation of the acceleration PI parameter is to calculate the Kp proportion parameter and the Ki integral parameter under different accelerations through a current acceleration table, when the acceleration is higher, the required torque of the whole vehicle is relatively larger, the torque required to be calculated at the time of cruising is also increased, when the acceleration is higher, the Kp parameter value and the Ki parameter value are also larger, the Kp parameter value and the Ki parameter value can be set as calibration parameters, and the calibration change is carried out through the actual condition of the vehicle to formulate a proper value.

Preferably, the vehicle weight state judgment is to acquire the vehicle weight information transmitted by the external module, judge that the current vehicle is in one of the idle state, the medium state and the heavy state through different thresholds, and influence the required torque by the vehicle load, when the vehicle load is larger, the required whole vehicle torque is also larger, and then the compensation torque corresponding to the vehicle weight is also required to be increased.

Preferably, the basic torque calculation is to calculate basic torque values at different speeds by collecting a current speed table, when the speed is higher, the required torque of the whole vehicle is relatively larger, when the vehicle enters the cruising speed from the current speed, in order to reach the cruising target speed faster, the driver can not feel the descending of the speed or the situation that the whole vehicle has a tourist car in the adjusting process, the torque required to be cruising calculated at the moment is also increased, in order to achieve the aim, when the speed is higher, the requirement of the basic torque value is also larger, the basic torque value can be set as a calibration parameter, and the effective value is calibrated, changed and formulated through the actual situation of the vehicle.

The invention has the following beneficial effects:

the method for calculating the constant-speed cruising torque of the heavy truck based on multi-parameter control is suitable for calculating cruising torque under different speeds, different accelerations and different loads, achieves the purposes of reaching a cruising target speed quickly, meeting the current required torque of the whole truck, enabling the state of the truck to be stably switched when the truck enters cruising, enabling the torque to be stably changed, and further reducing the fuel consumption rate; calculating different PI parameter values according to different current vehicle speed states, and finally calculating the cruising required torque according to current vehicle condition information by adopting different torque calculation modes, so that the cruising target vehicle speed can be quickly reached, and the stability of the vehicle is maintained; the control method can be autonomously applied to cruise speed control under various vehicle conditions, does not need to manually calibrate PI parameters under special working conditions, and improves the intelligent and accurate control of the vehicle.

Drawings

FIG. 1 is a block diagram of a cruise target torque calculation control system.

Fig. 2 is a cruise torque calculation flowchart.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

As shown in FIG. 1, the constant-speed cruising torque calculation control system of the heavy truck based on multi-parameter control comprises a cruising torque calculation control unit, parameters collected by the cruising torque calculation control unit and cruising torque output, wherein the parameters collected by the cruising torque calculation control unit comprise a current vehicle speed, vehicle weight information, cruising target vehicle speed, cruising torque calculation enabling signals and torque values at the last moment, a torque calculation method enabling module, a difference value calculation module, a vehicle speed PI parameter calculation module, an acceleration PI parameter calculation module and a vehicle weight state judgment module are arranged in the cruising torque calculation control unit, and vehicle speed PI adjustment torque value calculation, acceleration PI adjustment torque value calculation, vehicle weight compensation torque calculation and basic torque calculation are carried out in the cruising torque calculation control unit according to the modules.

When the driver operates the vehicle to enter a constant-speed cruising state, the cruising torque calculation control unit calculates cruising torque in a multi-parameter control mode, so that the cruising target vehicle speed is quickly reached. The multiple parameters comprise a vehicle speed PI regulating torque value, an acceleration PI regulating torque value, a compensation torque value generated by a vehicle weight parameter, a basic torque value under different vehicle speeds and a torque value at the last moment. The control unit judges and calculates a method of a target torque value according to the current vehicle condition information. The current vehicle condition information comprises a current vehicle speed, vehicle weight information, a cruising target vehicle speed, a cruising torque calculation module enabling signal and a torque value at the last moment.

The torque calculation method enables: the enabling condition selects the cruise torque calculation method, the cruise torque calculation method 1 is selected when the difference value between the current vehicle speed and the cruise target vehicle speed is less than or equal to the threshold value by judging whether the difference value between the current vehicle speed and the cruise target vehicle speed is in the threshold value range, and the cruise torque calculation method 2 is selected otherwise, so that the enabling condition selection and the cruise torque calculation method are not in fixed corresponding relation.

And (3) calculating a difference value: including vehicle speed difference calculation and acceleration difference calculation. The vehicle speed difference is calculated by the difference between the current vehicle speed and the cruising target vehicle speed. The vehicle acceleration difference is calculated by calculating the vehicle acceleration first, calculating the acceleration in one period through the difference between the current vehicle speed and the vehicle speed at the last moment, and calculating the average value of the acceleration in ten periods. The acceleration difference is obtained by subtracting the current vehicle acceleration from the acceleration target value corresponding to the vehicle speed difference table. When the acceleration target value increases with an increase in the vehicle speed difference and the vehicle speed difference is negative, the acceleration target value corresponds to a negative value.

Calculating a vehicle speed PI parameter: the Kp proportion parameter and the Ki integral parameter under different vehicle speeds are calculated through collecting a current vehicle speed table, when the vehicle speed is higher, the required torque of the whole vehicle is relatively larger, when the vehicle enters the cruising vehicle speed from the current vehicle speed, in order to reach the cruising target vehicle speed faster, the driver can not feel the condition that the vehicle speed is reduced in the adjusting process, or the whole vehicle has a traveling condition, the torque required to be cruising calculated at the moment is also increased, and in order to achieve the purpose, when the vehicle speed is higher, the Kp parameter value and the Ki parameter value are also larger. Kp and Ki parameter values can be set as calibration parameters, and proper values are formulated by calibration change according to actual conditions of the vehicle.

Acceleration PI parameter calculation: kp proportional parameters and Ki integral parameters under different accelerations are calculated through a current acceleration table, when the acceleration is high, the required torque of the whole vehicle is relatively large, the torque required to be calculated at the moment is also increased, and when the acceleration is high, kp parameter values and Ki parameter values are also large. Kp and Ki parameter values can be set as calibration parameters, and proper values are formulated by calibration change according to actual conditions of the vehicle.

Judging the weight state: and acquiring the weight information transmitted by the external module, and judging whether the current vehicle is in one of the idle state, the medium load state and the heavy load state according to different thresholds. When the vehicle load influences the required torque, and when the vehicle load is larger, the required whole vehicle torque is larger, and the compensation torque corresponding to the vehicle weight is also required to be increased.

Calculating a vehicle speed PI regulating torque value: the current vehicle speed Kp and Ki value inputs calculate a vehicle speed PI regulating torque value through a PI regulator.

Acceleration PI adjusts the torque value to calculate: the current acceleration Kp and Ki value inputs calculate an acceleration PI regulating torque value through a PI regulator.

Calculating the vehicle weight compensation torque: the current compensation torque is calculated by the weight state.

Base torque calculation: the basic torque value under different vehicle speeds is calculated through collecting a current vehicle speed table, the required torque of the whole vehicle is relatively larger when the vehicle speed is higher, when the vehicle enters the cruising vehicle speed from the current vehicle speed, in order to reach the cruising target vehicle speed faster, a driver cannot feel that the vehicle speed is reduced in the adjusting process, or the whole vehicle has a traveling car, the torque required to be cruising and calculated at the moment is increased along with the condition, and in order to achieve the aim, the required basic torque value is also larger along with the condition that the vehicle speed is higher. The basic torque value can be set as a calibration parameter, and the effective value is formulated by calibrating and changing the actual condition of the vehicle.

The torque calculation method adopts the calculation method 1 when the torque is judged to be within a certain interval, and adopts the calculation method 2 when the torque is judged to be outside the certain interval.

As shown in fig. 2, a method for calculating constant-speed cruising torque of a heavy truck based on multi-parameter control comprises the following steps:

after the driver turns on the cruise switch and the target vehicle speed is calculated, the cruise target torque calculation module is enabled, the torque calculation flow chart is shown as a figure 2, and the specific steps are as follows:

1) Step 1 calculates the following values:

torque calculation method enabling determination: calculating a current vehicle speed difference value according to the current vehicle speed and the cruising target vehicle speed, and calculating whether the current vehicle speed difference value is in a certain interval;

2) The torque value is calculated according to the output of the step 1, as follows:

torque value at last moment: and acquiring the torque output value at the previous moment in real time.

3) Judging that the torque calculation method is enabled, and selecting a torque calculation method 1 when the enabling is equal to 0, wherein the specific method is as follows:

vehicle speed Kp calculated torque value, vehicle speed Ki calculated torque value, vehicle weight compensation torque value and basic torque value

When the enable is equal to 1, torque calculation method 2 is selected, specifically as follows:

the acceleration Kp calculates a torque value + the acceleration Ki calculates a torque value + the vehicle weight compensation torque value + the torque value at the last moment.

It is noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The constant-speed cruising torque calculation method for the heavy truck based on multi-parameter control is characterized by comprising a cruising torque calculation control unit, parameters collected by the cruising torque calculation control unit and cruising torque output, wherein the parameters collected by the cruising torque calculation control unit comprise a current vehicle speed, vehicle weight information, cruising target vehicle speed, cruising torque calculation enabling signals and a torque value at the last moment, a torque calculation method enabling module, a difference value calculation module, a vehicle speed PI parameter calculation module, an acceleration PI parameter calculation module and a vehicle weight state judgment module are arranged in the cruising torque calculation control unit, and vehicle speed PI adjustment torque value calculation, acceleration PI adjustment torque value calculation, vehicle weight compensation torque calculation and basic torque calculation are carried out in the cruising torque calculation control unit according to the modules;

the method specifically comprises the following steps:

s3, calculating a torque value:

2. The method for calculating the constant-speed cruising torque of the heavy truck based on multi-parameter control according to claim 1, wherein the torque calculation method enables to select the cruising torque calculation method, and the cruising torque calculation method 1 is selected when the difference between the current vehicle speed and the cruising target vehicle speed is less than or equal to the threshold value by judging whether the difference between the current vehicle speed and the cruising target vehicle speed is within the threshold value range, and the cruising torque calculation method 2 is selected otherwise.

3. The method for calculating the constant-speed cruising torque of the heavy truck based on multi-parameter control according to claim 1, wherein the difference calculation comprises calculation of a vehicle speed difference and calculation of an acceleration difference, the vehicle speed difference is calculated by calculating a current vehicle speed and a cruising target vehicle speed difference, the vehicle acceleration difference is calculated by calculating the vehicle acceleration first, the acceleration is calculated by calculating the acceleration in one period by the current vehicle speed and the vehicle speed difference at the last time, the average value of the acceleration in ten periods is calculated by accumulating, the acceleration difference is obtained by subtracting the current vehicle acceleration from the acceleration target value corresponding to the vehicle speed difference by looking up the vehicle speed difference, the acceleration target value is increased along with the increase of the vehicle speed difference, and the acceleration target value is also negative when the vehicle speed difference is negative.

4. The method for calculating the constant-speed cruising torque of the heavy truck based on multi-parameter control according to claim 1, wherein the calculation of the vehicle speed PI parameter is to calculate Kp proportion parameters and Ki integral parameters under different vehicle speeds by collecting a table of the current vehicle speed, the required torque of the whole truck is relatively larger when the vehicle enters the cruising speed from the current vehicle speed, in order to achieve the cruising target vehicle speed faster, a driver cannot feel the reduction of the vehicle speed in the adjusting process, or the whole truck has the condition of a traveling vehicle, the torque required to be calculated at the moment is increased along with the reduction, in order to achieve the aim, the Kp parameter value and the Ki parameter value are also larger along with the reduction, the Kp parameter value and the Ki parameter value can be set as calibration parameters, and the proper value is calibrated and changed through the actual condition of the vehicle.

5. The method for calculating the constant-speed cruising torque of the heavy truck based on multi-parameter control according to claim 1, wherein the calculation of the acceleration PI parameter is to calculate Kp proportion parameters and Ki integral parameters under different accelerations through a current acceleration table, the torque required by the whole truck is relatively larger when the acceleration is higher, the torque required by cruising calculation is also increased at the moment, the Kp parameter value and the Ki parameter value are also larger when the acceleration is higher, the Kp parameter value and the Ki parameter value can be set as calibration parameters, and proper values are formulated through calibration change of actual conditions of the truck.

6. The method for calculating the constant-speed cruising torque of the heavy truck based on multi-parameter control according to claim 1, wherein the weight state judgment is to acquire weight information transmitted by an external module, judge that the current vehicle is in one of no-load, medium-load and heavy-load states through different thresholds, influence the required torque by the vehicle load, and when the vehicle load is larger, the required whole-vehicle torque is larger, and the compensation torque corresponding to the weight of the vehicle is also required to be increased.

7. The method for calculating the constant-speed cruising torque of the heavy truck based on multi-parameter control according to claim 1, wherein the calculation of the basic torque is to calculate basic torque values at different speeds by collecting a table of the current speed, the required torque of the whole truck is relatively larger when the speed is higher, when the vehicle enters the cruising speed from the current speed, in order to reach the cruising target speed faster, the driver can not feel the speed is reduced in the adjusting process, or the situation that the whole truck has a cruising vehicle is required, the torque required to be calculated at the moment is also increased, in order to achieve the purpose, the requirement of the basic torque value is also larger when the speed is higher, the basic torque value can be set as a calibration parameter, and the effective value is formulated by calibrating and changing the actual situation of the vehicle.