CN103693102B - A kind of test method of vehicle front deflection angle - Google Patents

Abstract

The invention discloses a method for testing the steering angle of an automobile front wheel, which is characterized in that: a testing system including a laser emitter and a laser receiving device is provided; The light plane parallel to the rim of the wheel; the laser receiving device composed of two laser receivers is used to form the laser receiving plane, and intersects with the light plane to form a detection line. wheel steering angle information. The method for testing the steering angle of the front wheel of the automobile adopted by the invention has high testing accuracy and is convenient for installation, and is suitable for measuring the steering angle of the front wheel under various driving conditions of the automobile.

Description

A method for testing the steering angle of an automobile front wheel

technical field

The invention belongs to the field of automobile testing and control, and in particular relates to a method for measuring the steering angle of an automobile front wheel.

Background technique

The cornering characteristics of the tire directly affect the handling stability and driving safety of the car. Among them, the cornering characteristics of the tire are the basis of the research on the handling stability of modern cars. The left and right wheels determine the cornering characteristics of the axle. It determines the steering characteristics of the vehicle. The vehicle dynamics stability control system needs to identify the steering characteristics of the vehicle in real time and adjust it through the brake force or engine output torque to ensure that the vehicle has moderate understeer characteristics. The steering characteristics of a car can be expressed quantitatively based on the difference between the slip angles of the front and rear axles. In the tire slip characteristics, the slip angle is the angle between the horizontal velocity direction of the tire contact point and the tire plane. To obtain the slip angle, it is necessary to accurately obtain the steering angle of the front wheel of the car, that is, the distance between the steering wheel plane and the longitudinal axis of the car when the car is running. angle.

In the prior art, there are mainly indirect measurement methods and observation methods based on dynamic models to obtain the steering angle of the front wheels of automobiles.

The indirect measurement method is mainly based on the steering wheel angle to obtain the front wheel steering angle. During the driving process of the car, when the lateral acceleration is less than 0.4g, the front wheel steering angle and the steering wheel angle basically maintain a linear relationship. At this time, the indirect measurement method has higher accuracy. Under extreme conditions, the lateral acceleration of the vehicle is greater than 0.4g, and the steering angle of the front wheels is also superimposed on the suspension deformation steering and the body roll steering angle, resulting in a large error in obtaining the steering wheel steering angle based on the steering wheel angle. In addition, the extreme working conditions of the vehicle are generally accompanied by the transfer of the vehicle load to the front, rear or outer wheels, resulting in the transfer of the cornering characteristic working area of a single tire, weakening the axle cornering characteristic, and thus changing the steering characteristics of the vehicle. Therefore, it is a difficult problem to accurately observe the steering characteristics of automobiles under extreme conditions.

Based on the observation method of the dynamic model, the multi-degree-of-freedom dynamic model and the AFS model of the car are established to observe the information of the front wheel steering angle of the car. The accuracy of the model will directly affect the observation accuracy of the front wheel steering angle. Under high-speed driving conditions with large steering wheel angles, data convergence speed and accuracy are affected.

In addition, there is a method of measuring the turntable by using the angle of the vehicle, but this method has great limitations and is only suitable for the measurement of the vehicle in a stationary state.

Contents of the invention

The present invention provides a method for testing the steering angle of the front wheel of an automobile with wide application range, simple operation and high precision in order to avoid the disadvantages of the above-mentioned prior art.

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

The test method of the automobile front wheel steering angle of the present invention is characterized in that: a test device is set, and the test device includes a laser transmitter and a laser receiver;

The laser transmitter is fixedly arranged on the wheel rim on the right side of the car, and the central axis of the wheel rim coincides with the central axis of the laser transmitter; the laser transmitter is used to send laser signals in real time to form a light plane pp' , the light plane pp' is perpendicular to the central axis of the wheel rim;

The laser receiving device comprises a first laser receiver and a second laser receiver; the first laser receiver and the second laser receiver are columnar; one end of the first laser receiver is fixed on the right outside of the car hood At point C, the other end extends outward along the horizontal direction; one end of the second laser receiver is fixed at point D on the right outside of the car hood, and the other end extends outward along the horizontal direction; the distance between point C and point D is f, and The first laser receiver and the second laser receiver are parallel to each other and perpendicular to the line connecting point C and point D, with the first laser receiver, the second laser receiver and the line connecting point C and point D as sides to form a plane parallel to the horizontal plane The rectangular laser receiving plane ww'; the vertical distance between the rectangular laser receiving plane ww' and the center point of the wheel on the right side of the car is d;

The rectangular laser receiving plane ww' intersects the light plane pp' formed by the laser transmitter to form a detection line A'B', wherein point A' is the intersection point formed by the detection line and the first laser receiver, point B' It is the intersection point formed by the detection line and the second laser receiver; the first laser receiver receives the laser signal of point A', and uses the laser signal of point A' to obtain the distance e between point A' and point C; the second laser receiver receives The device receives the laser signal at point B', and uses the laser signal at point B' to obtain the distance f between point B' and point D;

The steering angle δ of the front wheels of the car is calculated by formula 1:

$\mathrm{<span\; class="notranslate">\; \&delta;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arctan</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; e</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; g</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

The test method of the steering angle of the front wheel of the automobile of the present invention is characterized in that: the test device also includes a laser emitter connecting device; the laser emitter connecting device includes a flange, a connecting rod, a clamping sleeve, and a claw head , bolts; one side of the flange is fixedly connected to the laser transmitter through a connecting rod, and the other side of the flange is fixedly connected to the wheel rim through a clamping sleeve; the clamping sleeve is fastened to the On the flange, the jaw head at the other end of the clamping sleeve is fixed on the wheel rim.

Compared with the prior art, the beneficial effects of the present invention are reflected in:

1. The present invention adopts the method of testing the steering angle of the front wheel of an automobile by installing a laser transmitter on the outside of the wheel rim on the right side of the automobile and installing a laser receiving device on the outside on the right side of the hood. It has high test accuracy and is applicable to various automobiles. Front wheel steering angle measurement under driving conditions;

2. The test device used in the present invention is low in cost and easy to install.

Description of drawings

Fig. 1 is the installation schematic diagram of test device of the present invention;

Fig. 2 is a schematic diagram of the installation height of the laser receiving device of the present invention;

Fig. 3 is a schematic diagram of the detection line formed by the intersection of the light plane and the rectangular laser receiving plane of the present invention;

Fig. 4 is the schematic diagram of the laser emitter connecting device of the present invention;

Fig. 5 is the schematic diagram of calculating the steering angle of the front wheel of the automobile of the present invention;

Symbols in the figure: 1 laser transmitter; 2 first laser receiver; 3 second laser receiver; 4 wheel rim; 5 connecting rod; 6 clamping sleeve; 7 claw head; 8 bolt; 9 flange.

Detailed ways

As shown in Figure 1, the test method of the steering angle of the front wheel of the automobile in this embodiment is: a test device is set, and the test device includes a laser transmitter 1 and a laser receiving device; The precise measurement of the angle, its installation and testing methods take the right front wheel of the car as an example.

As shown in Figure 3, the laser transmitter 1 is fixedly installed on the wheel rim 4 on the right side of the car, and the central axis of the wheel rim 4 coincides with the central axis of the laser transmitter 1; in order to accurately reflect the corner information, the laser transmitter is selected The device 1 is capable of sending a 360° radial beam without interruption. The laser transmitter 1 is used to send laser signals in real time to form a light plane pp', which is perpendicular to the central axis of the wheel rim 4; when the front wheel of the car turns, the light plane pp' rotates with the wheel rim 4.

The laser receiving device comprises a first laser receiver 2 and a second laser receiver 3; the first laser receiver 2 and the second laser receiver 3 are columnar and the length meets the requirement that the car can normally receive laser signals at a large steering angle; One end of a laser receiver 2 is fixed on point C on the right outside of the car hood, and the other end extends outward along the horizontal direction; one end of the second laser receiver 3 is fixed on point D on the right outside of the car hood, and the other end Extend outward along the horizontal direction; the distance between point C and point D is f, and the first laser receiver 2 and the second laser receiver 3 are parallel to each other and perpendicular to the line connecting point C and point D, with the first laser receiver 2 , the second laser receiver 3 and point C and point D are connected as a side to form a rectangular laser receiving plane ww' parallel to the horizontal plane; the vertical distance between the rectangular laser receiving plane ww' and the center point of the wheel on the right side of the automobile is d; appropriately expand The distance between points C and D is conducive to improving the accuracy of angle recognition.

The rectangular laser receiving plane ww' intersects the optical plane pp' formed by the laser transmitter 1 to form a detection line A'B', where A' point is the intersection point formed by the detection line and the first laser receiver 2, and B' point is the detection line The intersection formed by the line with the second laser receiver 3 ; the detection line A′B′ maintains the same angular variation as the wheel rim 4 . The first laser receiver 2 receives the laser signal of point A', uses the position of the point A' to compare with the reference position to generate a deviation signal, and the first laser receiver 2 solves the deviation signal to obtain point A' and C The distance e of the point; the second laser receiver 3 receives the laser signal of the B' point, and similarly utilizes the deviation signal generated by comparing the position of the B' point with the reference position to obtain the distance g between the B' point and the D point;

As shown in Figure 5, the front wheel steering angle δ of the car is calculated by formula 1:

$\mathrm{<span\; class="notranslate">\; \&delta;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arctan</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; e</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; g</span>}}{\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

In specific implementation, the test device also includes a laser transmitter connection device; as shown in Figure 4, the laser transmitter connection device includes a flange 9, a connecting rod 5, a clamping sleeve 6, a claw head 7, and a bolt 8; One side of the flange 9 is fixedly connected with the laser transmitter 1 through the connecting rod 5, and the other side of the flange 9 is fixedly connected with the wheel rim 9 through the clamping sleeve 6; the clamping sleeve 6 is fastened on the On the flange 9 , the claw head 7 at the other end of the clamping sleeve 6 is fixed on the wheel rim 4 .

Claims (2)

1. a test method for vehicle front deflection angle, is characterized in that: arrange proving installation, and described proving installation comprises laser transimitter (1) and laser receiver;

Described laser transimitter (1) is fixedly installed on the rim for automobile wheel (4) of car right side, and the central axes of the central axis of described rim for automobile wheel (4) and described laser transimitter (1); Described laser transimitter (1) forms optical plane pp ' for sending laser signal in real time, the central axis upright of described optical plane pp ' and rim for automobile wheel (4);

Described laser receiver comprises the first laser pickoff (2) and the second laser pickoff (3); Described first laser pickoff (2) and the second laser pickoff (3) are in column; One end of first laser pickoff (2) is fixed on the C point of the rightmost outer of automobile engine cover, and the other end stretches out in the horizontal direction; One end of second laser pickoff (3) is fixed on the D point of the rightmost outer of automobile engine cover, and the other end stretches out in the horizontal direction; C point and D dot spacing are f, and the first laser pickoff (2) and the second laser pickoff (3) are parallel to each other and perpendicular to C point and D point line, are that limit forms the rectangular laser receiving plane ww ' being parallel to horizontal surface with the first laser pickoff (2), the second laser pickoff (3) and C point and D point line; Described rectangular laser receiving plane ww ' is d with the vertical distance of car right side wheel center point;

Described rectangular laser receiving plane ww ' formation crossing with the optical plane pp ' that described laser transimitter (1) is formed detection line A ' B ', wherein A ' some intersection point being detection line and the first laser pickoff (2) and being formed, B ' some intersection point being detection line and the second laser pickoff (3) and being formed; First laser pickoff (2) receives the laser signal of A ', utilizes laser signal acquisition A ' of described A ' and the distance e of C point; Second laser pickoff (3) receives the laser signal of B ', utilizes laser signal acquisition B ' of described B ' and the distance g of D point;

Described vehicle front steering angle sigma calculates acquisition by formula 1:

$\mathrm{\&delta;}=arctan\left(\frac{e-g}{f}\right)---\left(1\right).$

2. the test method of vehicle front deflection angle according to claim 1, is characterized in that: described proving installation also comprises laser transimitter connecting device; Described laser transimitter connecting device comprises flange (9), pipe link (5), gripping sleeve (6), claw head (7), bolt (8); The side of described flange (9) is fixedly connected with by pipe link (5) with laser transimitter (1), and the opposite side of flange (9) is fixedly connected with rim for automobile wheel (9) by gripping sleeve (6); Described gripping sleeve (6) is fastened on flange (9) by bolt (8), and the claw head (7) of the other end of gripping sleeve (6) is fixed on rim for automobile wheel (4).