阅读说明：本技术 一种履带式车辆的方向盘转向判断与转角计算方法 (Steering wheel steering judgment and corner calculation method for tracked vehicle ) 是由 夏光 施展 刘贤阳 魏志详 夏岩 张华磊 陈建杉 汪韶杰 孙保群 于 2021-08-16 设计创作，主要内容包括：本发明公开了一种履带式车辆的方向盘转向判断与转角计算方法,其步骤是：首先通过判断转向盘转向,实现对转向信号的读取,此后确定转向盘圈数从而实现对于转向角度初始值的替换,而后通过转向泵控制转向动作的完成,确保转向盘转角处于一定的误差范围内,实现精准转向。本发明能够提高驾驶员在进行转向操作时的安全性与方向感。(The invention discloses a method for judging steering wheel steering and calculating a steering angle of a tracked vehicle, which comprises the following steps: the method comprises the steps of firstly judging steering of a steering wheel, reading a steering signal, determining the number of turns of the steering wheel, replacing an initial value of a steering angle, controlling the completion of a steering action through a steering pump, ensuring that the turning angle of the steering wheel is within a certain error range, and realizing accurate steering. The invention can improve the safety and the direction sense of a driver during steering operation.)

1. A steering wheel steering judgment and turning angle calculation method of a tracked vehicle is characterized by comprising the following steps:

step 1, setting two zone bits, namely a first zone bit Area1flag and a second zone bit Area2flag, in a rotating circumference of a steering wheel;

step 2, using the initial position SA of the steering wheel₀To divide the steering wheel into two quadrants, 0-SA₀Quadrant 1 area of (SA)₀-quadrant 2 area of 360 °;

the first zone bit Area1flag is positioned at a 0-degree point in the rotating circumference, and the second zone bit Area2flag is positioned at SA₀Point;

step 3, a corner sensor is arranged between the steering wheel and the steering mechanism; thereby detecting an initial position SA of the steering wheel using the rotation angle sensor₀；

Step 4, the steering angle sensor judges whether the rotation condition of the steering wheel is positive rotation or negative rotation according to the positive and negative of the change value dir of the steering wheel steering angle at the current moment and the steering wheel steering angle at the previous moment; if dir is greater than 0, the steering wheel is judged to be in forward rotation, and if dir is less than 0, the steering wheel is judged to be in reverse rotation;

step 5, starting to acquire the rotation turn loop of the steering wheel at the current moment;

step 6, if the steering wheel rotates forwards, judging whether the rotation angle change value dir of the steering wheel at two moments is in a quadrant 1 Area, if so, setting a first flag position Area1flag to be 1, and executing a step 7; otherwise, after setting the first flag position Area1flag to be 0, executing the step 9;

if the steering wheel is reversed, judging whether the corner change value dir of the steering wheel at two moments is in a quadrant 2 Area, if so, setting a second zone position Area2flag to be 1, and executing a step 8; otherwise, after setting the second flag position Area2flag to "0", executing step 9;

step 7, judging whether the steering wheel angle at the current moment passes through a second zone position Area2flag or not; if so, adding 1 to the number of turns loop of the steering wheel, otherwise, keeping the number of turns loop of the steering wheel unchanged;

step 8, judging whether the steering wheel corner at the current moment passes through a first zone bit Area1 flag; if so, adding 1 to the number loop of the rotation turns of the steering wheel, otherwise, keeping the number loop of the rotation turns of the steering wheel unchanged;

and 9, calculating the absolute rotation angle theta of the steering wheel at the current moment by using the formula (1):

θ＝loop×360°+SA-SA₀ (1)

in equation (1), SA represents the steering angle position of the steering wheel at the present time.

2. The steering wheel steering judgment and turn calculation method according to claim 1, wherein when the tracked vehicle enters the pivot steering condition, the turn sensor acquires an initial turn point of pivot steering, so as to obtain an initial turn value of pivot steering, and if the absolute turn angle of the steering wheel at the current time changes, the relative turn angle of pivot steering is made equal to the difference between the absolute turn angle of the steering wheel at the current time and the initial turn value of pivot steering, and is used as the initial value of the pivot steering condition to be input to a subsequent execution element.

3. The steering wheel turning judgment and turn angle calculation method according to claim 1,

when the tracked vehicle keeps running straight and has no direction change, the tracked vehicle is allowed to enter a forward steering working condition;

when the forward steering working condition is entered, the corner sensor collects an initial corner point of forward steering so as to obtain an initial corner value of forward steering, and if the absolute corner of the steering wheel at the current moment changes, the relative corner of forward steering is made to be equal to the difference value between the absolute corner of the steering wheel at the current moment and the initial corner value of forward steering, and the relative corner is used as the initial value of the forward steering working condition and is input into a subsequent execution element.

Technical Field

The invention relates to the field of hydraulic steering control, in particular to a steering wheel steering judgment and turning angle calculation method for a tracked vehicle.

Background

With the progress and the technical development of the times, the application fields of engineering machinery, special vehicles and the like are more and more extensive, the application environments are more and more complex, the requirements of people on the working performance of the machinery and the vehicles are gradually increased, particularly, the driving safety, the comfort and the operation efficiency are emphasized, and meanwhile, the requirements on the hydraulic steering capacity and the accuracy are increased.

The actual working condition of the traditional hydraulic steering mechanism is complex and changeable, installation errors and leakage conditions can not be avoided to directly influence the judgment and information acquisition of a corner signal acquisition system, so that the steering wheel and a steering wheel can not form an accurate corresponding relation, a driver can not accurately control the steering movement of the vehicle when driving the vehicle, and the steering safety and the stability of the vehicle are seriously influenced. By adopting the wire control hydraulic steering system, the accurate corresponding relation between the steering wheel and the steering wheel can be realized, active steering can be better executed, a more flexible arrangement mode is obtained, the vehicle can be ensured to follow the will of a driver when the vehicle turns, the fatigue of the driver is reduced, and the driving operation precision is improved.

In the steer-by-wire hydraulic steering system, in the steering wheel rotating process, if the steering wheel corner signal can not be read accurately, the replacement of the steering initial angle can be further influenced, so that the linear relation between the steering wheel and the steering wheel corner is changed, the steering operation executed by a steering pump is greatly influenced, and the safety of vehicle driving and the difficulty of vehicle operation are greatly influenced. The reading of the steering wheel signal and the replacement of the steering initiation angle for a hydraulic-by-wire steering system is therefore critical to achieving steer-by-wire.

Disclosure of Invention

In order to avoid the defects of the prior art, the invention provides the steering wheel steering judgment and corner calculation method of the tracked vehicle, so that the steering wheel and the steering wheel can be accurately matched in the steering process, and the driving safety and the direction sense of a driver are improved.

The invention adopts the following technical scheme for solving the technical problems:

the invention relates to a method for judging steering wheel steering and calculating a steering angle of a tracked vehicle, which is characterized by comprising the following steps:

step 1, setting two zone bits, namely a first zone bit Area1flag and a second zone bit Area2flag, in a rotating circumference of a steering wheel;

step 2, using the initial position SA of the steering wheel₀To divide the steering wheel into two quadrants, 0-SA₀Quadrant 1 area of (SA)₀-quadrant 2 area of 360 °;

the first zone bit Area1flag is positioned at a 0-degree point in the rotating circumference, and the second zone bit Area2flag is positioned at SA₀Point;

step 3, a corner sensor is arranged between the steering wheel and the steering mechanism; thereby detecting an initial position SA of the steering wheel using the rotation angle sensor₀；

Step 4, the steering angle sensor judges whether the rotation condition of the steering wheel is positive rotation or negative rotation according to the positive and negative of the change value dir of the steering wheel steering angle at the current moment and the steering wheel steering angle at the previous moment; if dir is greater than 0, the steering wheel is judged to be in forward rotation, and if dir is less than 0, the steering wheel is judged to be in reverse rotation;

step 5, starting to acquire the rotation turn loop of the steering wheel at the current moment;

step 6, if the steering wheel rotates forwards, judging whether the rotation angle change value dir of the steering wheel at two moments is in a quadrant 1 Area, if so, setting a first flag position Area1flag to be 1, and executing a step 7; otherwise, after setting the first flag position Area1flag to be 0, executing the step 9;

if the steering wheel is reversed, judging whether the corner change value dir of the steering wheel at two moments is in a quadrant 2 Area, if so, setting a second zone position Area2flag to be 1, and executing a step 8; otherwise, after setting the second flag position Area2flag to "0", executing step 9;

step 7, judging whether the steering wheel angle at the current moment passes through a second zone position Area2flag or not; if so, adding 1 to the number of turns loop of the steering wheel, otherwise, keeping the number of turns loop of the steering wheel unchanged;

step 8, judging whether the steering wheel corner at the current moment passes through a first zone bit Area1 flag; if so, adding 1 to the number loop of the rotation turns of the steering wheel, otherwise, keeping the number loop of the rotation turns of the steering wheel unchanged;

and 9, calculating the absolute rotation angle theta of the steering wheel at the current moment by using the formula (1):

θ＝loop×360°+SA-SA₀ (1)

in equation (1), SA represents the steering angle position of the steering wheel at the present time.

The steering wheel steering judgment and turn angle calculation method is characterized in that when the tracked vehicle enters the pivot steering working condition, the turn angle sensor acquires an initial turn angle point of pivot steering so as to obtain an initial turn angle value of the pivot steering, and if the absolute turn angle of the steering wheel at the current moment changes, the relative turn angle of the pivot steering is equal to the difference value between the absolute turn angle of the steering wheel at the current moment and the initial turn angle value of the pivot steering and is used as the initial value of the pivot steering working condition to be input into a subsequent execution element.

When the tracked vehicle keeps running straight and has no direction change, the tracked vehicle is allowed to enter a forward steering working condition;

when the forward steering working condition is entered, the corner sensor collects an initial corner point of forward steering so as to obtain an initial corner value of forward steering, and if the absolute corner of the steering wheel at the current moment changes, the relative corner of forward steering is made to be equal to the difference value between the absolute corner of the steering wheel at the current moment and the initial corner value of forward steering, and the relative corner is used as the initial value of the forward steering working condition and is input into a subsequent execution element.

Compared with the prior art, the invention has the beneficial effects that:

1. the invention divides the steering wheel rotation angle into two intervals, can judge the positive and negative rotation condition of the steering wheel, is beneficial to the accurate judgment of the rotation direction of the steering wheel, and improves the accuracy of reading the steering signal and the accuracy of the rotation of the steering wheel by determining the rotation number of the steering wheel through the C language program.

2. The invention realizes the replacement of the initial value of the steering angle, accurately calculates the initial value of the steering angle on the basis of collecting accurate turns and corners, completes the replacement of the initial value, and then the replaced initial value can provide a more accurate input value for a corner sensor to be used as the input value of a steering system, thereby realizing the control of the hydraulic pump to execute the steering operation and further improving the steering flexibility and accuracy.

3. According to the invention, through the accurate judgment of the steering direction and the accurate calculation of the absolute rotation angle, the rotation of the steering wheel conforms to the intention of a driver, the stability of the rotation of the steering wheel is ensured, the error prevention in the rotation process of the steering wheel is improved, the steering safety and the driving safety are improved, the automatic steering of a vehicle after flameout can be prevented, and the flexibility and the accuracy of the steering are ensured.

Drawings

FIG. 1 is a schematic view of the steering wheel zone division according to the present invention;

FIG. 2 is a flow chart of steering wheel steering determination and absolute turn angle calculation according to the present invention;

fig. 3 is a schematic diagram of an application environment of the hydraulic steering by wire according to the present invention.

Detailed Description

In the embodiment, the wire control hydraulic steering system of the tracked vehicle is generally used for low-speed heavy-load vehicles such as engineering machinery, forklifts, tractors and combine harvesters, and the wire control hydraulic steering system can realize one-to-one correspondence between a vehicle steering wheel and steering wheels, so that the steering intention of a driver is constantly ensured, the driving difficulty of operators is reduced, and the driving precision is improved. A steering wheel steering judgment and steering angle calculation method applied to a steer-by-wire hydraulic steering system, please refer to fig. 1, comprising:

firstly, the system is electrified to acquire the initial position SA of the corner sensor₀Two zone bits, namely a first zone bit Area1flag and a second zone bit Area2flag, are arranged in the rotating circumference of the steering wheel; then obtaining the specific position SA of the current steering wheel, and obtaining the initial position SA of the steering wheel₀To divide the steering wheel into two quadrants, 0-SA₀Quadrant 1 area of (SA)₀Quadrant 2 Area of 360 °, wherein the first zone Area1flag is located at the 0 ° point within the rotation circle and the second zone Area2flag is located at SA₀Point;

in addition, a steering angle sensor is arranged between the steering wheel and the steering mechanism, and the steering angle sensor can judge whether the rotation condition of the steering wheel is positive rotation or negative rotation according to the positive and negative of the change value dir of the steering wheel at the current moment and the steering wheel at the previous moment; please refer to fig. 2, if dir>0, it is determined that the steering wheel is rotating in the forward direction, and dir<0, the steering wheel is determined to be reversed. Meanwhile, the system starts to collect the rotation turns loop of the steering wheel, and accurately calculates the rotation turns according to different steering conditions of the steering wheel, wherein the rotation turns loop is divided into the following two conditions: if the steering wheel rotates forwards, whether the change value dir of the rotation angle of the steering wheel at two moments is in a quadrant 1 Area is judged, if so, a first zone position Area1flag is set to be 1, whether the rotation angle of the steering wheel at the current moment passes a second zone position Area2flag is judged, and if so, the number of rotation turns loop of the steering wheel is added with 1. Otherwise, keeping the rotation circle loop of the steering wheel unchanged; if the first flag bit Area1flag is set to "0", the steering wheel absolute rotation angle formula θ ═ loop × 360 ° + SA-SA is obtained according to the current time absolute rotation angle formula θ₀Calculation is performed, where SA represents the steering angle position of the steering wheel at the present time. If the steering wheel is in reverse rotation, whether the rotation angle change value dir of the steering wheel at two moments is in a quadrant 2 Area is judged, if so, a second zone position Area2flag is set to be 1, whether the rotation angle of the steering wheel at the current moment passes through a first zone position Area1flag is judged, and if so, the number of rotation turns loop of the steering wheel is added with 1. Otherwise, keeping the rotation circle loop of the steering wheel unchanged; if the second flag bit Area2flag is set to "0", the steering wheel absolute rotation angle formula θ is loop × 360 ° according to the current time+SA-SA₀Calculating, wherein in the case of positive rotation, the 0 point is Area1flag, SA₀Is Area2 flag; in the case of inversion, the 0-bit Area2flag, SA₀Is Area1 flag; meanwhile, due to the special working conditions of the tracked vehicle, the working conditions of pivot steering and advancing steering are included: when the tracked vehicle enters the pivot steering working condition, the corner sensor acquires an initial corner point of pivot steering so as to obtain an initial corner value of the pivot steering, and if the absolute corner of the steering wheel at the current moment changes, the relative corner of the pivot steering is made to be equal to the difference value between the absolute corner of the steering wheel at the current moment and the initial corner value of the pivot steering, and the relative corner is used as the initial value of the pivot steering working condition and is input into a subsequent execution element; the forward steering condition is allowed to be entered while the tracked vehicle remains traveling straight and without a change in direction. When the forward steering working condition is entered, the corner sensor collects an initial corner point of forward steering so as to obtain an initial corner value of forward steering, and if the absolute corner of the steering wheel at the current moment changes, the relative corner of forward steering is made to be equal to the difference value between the absolute corner of the steering wheel at the current moment and the initial corner value of forward steering, and the relative corner is used as the initial value of the forward steering working condition and is input into a subsequent execution element.

The absolute rotation angles under respective conditions are obtained by reading the initial values of the above working conditions, please refer to fig. 3, the absolute rotation angles are used as input to enter a rotation angle controller, and are converted into electric signals through a series of calculation and control processes of a CAN bus module to be input into a static pressure system displacement adjusting mechanism, so that the displacement of left and right turning is controlled and adjusted. The displacement is changed to influence the opening angle of the bidirectional adjustable variable displacement pump, so that the flow passing through the bidirectional fixed displacement motor is controlled, the variable displacement pump and the fixed displacement motor form a steering static pressure system which is mechanically connected with the differential, the flow of the static pressure system is changed, the difference of the rotating speeds at two ends of the differential is changed, and the steering operation is realized.