CN116374002A - Real-time measuring device for actual rotation angle of wheel - Google Patents

Abstract

The invention provides a real-time measuring device for the actual rotation angle of a wheel, which comprises a sliding mechanism, a measuring mechanism, a rotating mechanism and a limiting mechanism. The steering knuckle is rigidly connected with the wheel, when the vehicle turns, the steering knuckle drives the wheel to rotate around the kingpin and simultaneously drives the shock absorber to rotate, the rotating base is fixedly connected with the steering knuckle and is connected with the fork arm through a bearing, the sliding mechanism is fixedly connected with the vehicle body through the sliding rail base, the sliding block is connected with the rotary encoder through the encoder bracket, the rotary encoder rotating shaft is fixedly connected with the rotating rod, the fork arm drives the rotating rod to rotate around the horizontal direction, the rotary encoder reads the rotating angle information of the rotating rod, and the rotating angle speed is calculated according to the rotating angle and time. The inner side of the limiting mechanism is fixedly connected with the shock absorber, and the outer side of the limiting mechanism is used for limiting the rotation of the fork arm along the rolling direction of the wheel through the rod system. The invention simplifies the measurement of the actual turning angle of the wheel, ensures the measurement precision, and can be used for the whole vehicle dynamics analysis and the real-time detection and control of the turning angle of the automatic driving wheel.

Description

A real-time measuring device for actual wheel rotation angle

technical field

The present application relates to the technical field of vehicles, and specifically designs a real-time measuring device for the actual rotation angle of a wheel.

Background technique

The steering-by-wire system of existing self-driving vehicles needs to detect the front wheel angle and angular velocity to achieve closed-loop control of the vehicle steering process. The wheel actually rotates around the kingpin, but the existence of the caster angle and inclination angle causes the wheel rotation trajectory to be an arc in space, which makes it difficult to accurately measure the wheel angle. Most of the existing technologies have expensive or expensive measuring devices. Inaccurate measurement data and other issues.

According to the definition of the wheel angle in SAE "Vehicle Dynamics Terminology" in the United States, the angle that actually affects the driving of the car is the angle of the wheel around the Z axis perpendicular to the ground.

At present, there are two main methods for measuring the wheel angle. The first one is calculated by the transmission ratio of the steering system. This method obtains the steering wheel angle from the sensor installed in the power steering motor, and then calculates the wheel angle through the steering gear ratio and the steering wheel angle. , because the steering transmission ratio is often nonlinear, the calculation of this method is more complicated, and it is difficult to exclude the error caused by the uncertainty factor on the measured value of the wheel angle.

Another method is to directly measure the rotation angle of the shock absorber, and approximate the rotation angle of the shock absorber to the wheel rotation angle. This method is suitable for vehicles whose kingpin coincides with the axis of the shock absorber, and for vehicles whose wheels rotate around the virtual kingpin , the first method is generally adopted. This method is to connect the angle sensor with the shock absorber, and output the rotation angle of the shock absorber through the sensor. However, due to the existence of caster angle and inclination angle of the kingpin, there is an error between the rotation angle measured by this method and the actual rotation angle of the wheel. As the rotation angle increases, the error also increases.

The above two commonly used methods do not take into account the vehicle loading and changes in road conditions, resulting in measurement data errors caused by suspension and wheel force deformation, so the two methods can only obtain rough values of the wheel angle, but the accuracy still needs to be improved. .

Therefore, how to accurately measure the size of the wheel rotation angle when the vehicle is running and ensure the measurement accuracy is a technical problem to be solved by those skilled in the art.

Contents of the invention

In the actual rotation process, the wheel rotates in an arc around the kingpin axis in space. The kingpin of most passenger cars is a virtual kingpin, and the impact of the road surface makes the suspension deform, which makes the wheel angle of the vehicle during driving Difficult to measure accurately.

In order to solve the above problems, this application overcomes the deficiencies in the prior art and provides a real-time measurement device for the actual wheel angle, which can accurately measure the wheel angle that affects the driving of the car, and ensure the measurement accuracy, and then be applied to vehicle dynamics analysis or automatic Driving angle control and other fields.

A real-time measuring device for the actual rotation angle of a wheel, comprising a sliding mechanism, a measuring mechanism, a rotating mechanism and a limit mechanism;

The sliding mechanism includes a slide rail base, a slider frame, a slider and a slide rail; the slide rail is installed on the vehicle body through the slide rail base; the slide block and the slide rail form a sliding pair; the slider frame fixed on the slider;

The measuring mechanism includes a rotary encoder, an encoder bracket and a rotary rod; the rotary encoder is installed on the slider frame through the encoder bracket; the rotary encoder is connected with a horizontally arranged rotary rod; the rotary encoder The encoder is installed vertically to collect the rotation angle and angular velocity of the rotating rod on the horizontal plane; the rotary encoder is connected to the CAN bus of the vehicle, and transmits the rotating angle and angular velocity of the rotating rod to the CAN bus;

The rotating mechanism includes a yoke, a bearing, and a rotating base. The rotating base is installed on the steering knuckle shaft, and the rotating base and the bearing adopt an interference fit; the lower end of the yoke is installed on the bearing; the upper end of the yoke has Two parallel bifurcations, both of which are provided with through slots, are used for the rotating rod to pass through horizontally, and the rotating rod slides freely in the through slots; and are constrained by the through slots to rotate in the horizontal direction; the setting of the through slots is to offset the wheels Jump up and down or vibrate.

The limit mechanism includes a limit rod, a limit rod seat, a fixed seat 1 and a fixed seat 2; the fixed seat 1 and the fixed seat 2 form an annular hoop, and are clamped on the shock absorber; The limit rod is fixedly connected with the ring clamp through the limit rod seat; the end of the limit rod is provided with a fork-shaped structure, and the fork-shaped structure clamps the middle part of the yoke.

The sliding mechanism does not rotate and move in space, and the measuring mechanism and the sliding mechanism can rotate and move relatively; Relative movement can occur in the horizontal direction, and the vertical direction is relatively fixed. Due to the limitation of the limit mechanism, the yoke in the rotating mechanism cannot rotate with the rolling of the wheel; the yoke can drive the measuring mechanism to rotate around the axis perpendicular to the ground As well as horizontal sliding, the two can move vertically and longitudinally relative to each other.

The slide rail base is rigidly connected to the vehicle body through bolts; the slide rail is rigidly connected to the slide rail base through bolts; the slider is rigidly connected to the slider frame through bolts; The slide rails can move relative to each other.

The rotary encoder is rigidly connected to the encoder bracket through bolts; the rotary encoder is connected to the rotating rod through fastening bolts, and the rotating rod is constrained by the yoke to rotate synchronously in the horizontal direction. The rotating rod is cylindrical. The rotating base adopts an interference fit with the bearing; the yoke and the bearing are matched by fastening bolts; the yoke and the rotating base can rotate relative to each other; due to the limitation of the limiting mechanism, the The wishbone does not rotate with the rolling of the wheel.

The first fixed seat and the second fixed seat are fixedly connected by bolts, and the middle size matches the diameter of the shock absorber so that it is clamped to the shock absorber; the limit rod and the limit rod seat Bolts are rigidly connected through the through holes at the bottom; a cylindrical plug is provided at the front end of the ring clamp, and a circular hole is correspondingly provided on the limit rod seat, and the cylindrical plug is inserted into the circular hole. The size of the cylindrical plug matches the round hole of the limit rod seat, and the ring clamp and the limit rod seat can rotate relative to each other. After being rotated to be perpendicular to the ground, the limit rod seat and the ring clamp are affixed with fastening bolts through the threaded holes on the side of the limit rod seat.

The sliding mechanism is installed and the measuring mechanism is installed on the rear side above the wheel.

The inner end of the rotating base is fixedly connected to the wheel through the bolt used for installing the wheel on the outer side of the steering knuckle.

Two forks are used at the top of the yoke to limit the swivel rod. The limit gap length at the upper end of the yoke is greater than the up and down stroke of the wheel.

Compared with the prior art, the present invention provides a real-time measuring device for the actual rotation angle of the wheel, which has the following beneficial effects:

The real-time measurement device for the actual rotation angle of the wheel is realized by a mechanical device. Through software modeling and DMU animation simulation analysis, the movement interference of the mechanical structure is eliminated, and the feasibility and reliability of the device are determined. Compared with the existing technology, the influence of the change of the wheel rotation angle due to the deformation of the suspension on the measurement results can be eliminated, and the measured wheel rotation angle is guaranteed to be the angle that the wheel rotates around the Z axis perpendicular to the ground, that is, the wheel rotation angle that directly affects the driving state of the car , In addition, the visualization of the output results can be realized through the CAN bus.

Description of drawings

Figure 1 is a schematic diagram of the wheel angle;

Fig. 2 is a schematic structural view of the wheel angle measuring device provided by the embodiment of the present application in use;

Fig. 3 is a structural schematic diagram of a limit mechanism;

Fig. 4 is the installation diagram of limit mechanism;

Fig. 5 is a schematic diagram of the connection relationship between the rotating rod, the yoke and the limit rod;

Figure 6 is an enlarged view of the installation relationship of the rotary encoder;

Accompanying drawing 1-accompanying drawing 6 label explanation is as follows

100-sliding mechanism; 110-slide rail base; 120-slider frame; 130-slider; 140-slide rail; 200-measurement mechanism; 210-rotary encoder; 220-encoder bracket; 230-rotary rod; 300-rotating mechanism; 310-yoke arm; 320-bearing; 330-rotating base; 400-limiting mechanism; 410-limiting rod; 420-limiting rod seat; ;

5-shock absorber; 6-steering knuckle; 7-wheel.

Implementation

In order to enable those skilled in the art to better understand the technical solutions of the present application, the present application will be further described in detail below with reference to specific examples in the accompanying drawings.

This embodiment provides a real-time measurement device for the actual wheel rotation angle, which is used to measure the rotation angle of the wheel 7 of the vehicle. The wheel rotation angle refers to the angle between the wheel plane and the longitudinal axis of the vehicle body on the ground projection. Specifically, the wheel 7 The angle of rotation around the kingpin, as shown in Figure 1, the wheel 7 rotates from position A to position B, and its wheel plane rotates from a to b, then the angle α between a and b is the wheel rotation angle, the designed The wheel angle measurement device needs to be able to measure the angle α in real time.

As shown in Figures 2 to 4, a real-time measuring device for the actual rotation angle of a wheel includes a sliding mechanism 100, a measuring mechanism 200, a rotating mechanism 300 and a limit mechanism 400;

The sliding mechanism 100 includes a slide rail base 110, a slider frame 120, a slider 130 and a slide rail 140;

The slide rail 140 is installed on the vehicle body through the slide rail base 110; the slide block 130 and the slide rail 140 form a sliding pair; the slide block frame 120 is fixed on the slide block 130;

The measuring mechanism 200 includes a rotary encoder 210, an encoder bracket 220 and a rotating rod 230; as shown in FIG. 6, the rotary encoder 210 is installed on the slider frame 120 through the encoder bracket 220;

The rotary encoder 210 is connected to the horizontally arranged rotary rod 230; the rotary encoder 210 is vertically installed for collecting the rotation angle and rotational angular velocity of the rotary rod 230 on the horizontal plane; the rotary encoder 210 is connected to the vehicle The CAN bus signal is connected, and the rotation angle of the rotating rod 230 and the rotation angular velocity are transmitted to the CAN bus;

The rotating mechanism 300 includes a yoke 310, a bearing 320, and a rotating base 330. The rotating base 330 is installed on the steering knuckle 6, and the rotating base 330 and the bearing 320 adopt an interference fit; the lower end of the yoke 310 is installed on the On the bearing 320; as shown in Figure 5, the upper end of the yoke 310 has two parallel bifurcations, and the bifurcations are all provided with through grooves, which are used for the rotating rod 230 to pass through horizontally, and the rotating rod 230 slides freely in the through groove; The rod 230 is constrained by the through slot of the yoke 310 to only rotate in the horizontal direction;

The limit mechanism 400 includes a limit rod 410, a limit rod seat 420, a fixed seat 430 and a fixed seat two 440; the fixed seat one 430 and the fixed seat two 440 form an annular clamp, and clamp Tightly on the shock absorber 5;

The limit rod 410 is fixedly connected with the annular clip through the limit rod seat 420;

A fork-shaped structure is provided at the end of the limiting rod 410 , and the fork-shaped structure is stuck in the middle of the fork arm 310 .

The specific movement relationship is:

The inner end of the turning mechanism 300 is fixedly connected to the outside of the steering knuckle 6, so the turning mechanism 300 will be driven to rotate around the kingpin when the wheel 7 rotates. The pin turns without rolling.

The rotating rod 230 in the measuring mechanism 200 is installed horizontally. Since the yoke 310 only rotates with the rotation of the wheel 7, the rotation angle of the yoke 310 in the direction perpendicular to the ground is the wheel angle. It will drive the rotating rod 230 to rotate, and because the rotating rod 230 is always kept horizontal during the movement, the angle rotated by the rotating rod 230 is the rotation angle of the fork arm 310 around the Z axis perpendicular to the ground, so the rotating rod 230 The function of can be equivalently understood as simulating the wheel axis a or b in Figure 1, and its own rotation angle is the change angle of the axis of the wheel 7, that is, the wheel angle, so it is only necessary to measure the rotation angle of the rotating rod 230 itself to obtain the wheel angle .

The wheel 7 rotates around the virtual kingpin during the actual rotation process, and the actual trajectory can be approximately regarded as an arc, so the spatial trajectory of the rotating rod 230 can also be approximately regarded as an arc. It rotates around the self-generated axis while It moves in the lateral direction, so when measuring the rotation angle of the rotation rod 230 , it is necessary to add the sliding mechanism 100 to offset the degree of freedom of the rotation rod 230 in the lateral direction before measuring the rotation angle.

During the actual vehicle movement, due to factors such as friction and inertia, the yoke 310 will roll along with the wheel 7, so a limit mechanism 400 is introduced to limit the rolling of the yoke 310, and the shock absorber 5 will rotate with the wheel When rotation occurs, in order to ensure that the yoke 310 remains vertical during the movement, the inner side of the limit mechanism 400 is selected to be fixed on the shock absorber 5 .

As shown in Figure 2, the slide rail base 110 is rigidly connected to the vehicle body, the inner end of the slide rail 140 is fixed to the slide rail base 110 by bolts, the slide block 130 is movably connected with the slide rail 140, and the slide block 130 can move along the slide rail. The rail 140 slides, the upper end of the slider frame 120 is fixed to the slider 130 through bolts, the lower end is fixed to the encoder bracket 220 through bolts, the main part of the rotary encoder 210 is fixed to the encoder bracket 220 through bolts, and the rotating shaft part It is fixedly connected with the rotating rod 230 by fastening bolts, the top of the yoke 310 is limitedly connected with the rotating rod 230, and the bottom end is provided with a threaded hole. After matching with the outer side of the bearing 320, it is connected with the fastening bolts through the threaded hole, and the inner side of the bearing is connected to the rotating base. The outer end of the seat 330 is connected by interference fit, and the inner end of the rotating base 330 is fixedly connected to the outer side of the wheel by bolts.

As shown in FIG. 3 , a cylindrical plug is provided at the front end of the ring clamp, and a circular hole is correspondingly provided on the limit rod seat 420 , and the cylindrical plug is inserted into the circular hole. The size of the cylindrical plug matches the round hole of the limit rod seat 420, and the relative rotation between the annular clamp and the limit rod seat 420 can occur, and its function is to offset the caster angle of the shock absorber 5, and the After the limiting rod base 420 is rotated to be perpendicular to the ground, the limiting rod base 420 is fixedly connected to the ring clamp with fastening bolts through the threaded holes on the sides of the limiting rod base 420 .

As shown in FIG. 4 , the outer end of the limit rod 410 in the limit mechanism 400 is connected to the fork arm 310 in limit.

In this embodiment, the specific structure of the fork 310 is not limited, and it can be set as a single fork with a certain width or in a foldable form.

The rotary encoder 210 can also calculate the rotational angular velocity, that is, the rotational angular velocity of the wheel 7 according to the rotational angle and time. How the rotary encoder senses the rotation angle of the rotary rod 230 and how to calculate the rotation angular velocity according to the rotation angle and time are well-known prior art for those skilled in the art, and will not be repeated here to save space.

In this embodiment, the rotary encoder is connected to the CAN signal receiver, and can transmit the real-time detected rotation angle and rotational angular velocity to the CAN signal receiver. Specifically, how the encoder is connected to the CAN signal receiver, and the real-time detection The transmission of the rotation angle and the rotation angular velocity to the receiver is a well-known prior art for those skilled in the art, and to save space, details are not repeated here.

Although the embodiment of the present invention has been described, for those skilled in the art, various optimizations, modifications, replacements and variations can be made to this embodiment without departing from the principle and spirit of the present invention. as defined by the appended claims and their equivalents.

Claims (2)

1. A real-time measuring device for the actual rotation angle of a wheel, characterized in that it includes a sliding mechanism (100), a measuring mechanism (200), a rotating mechanism (300) and a limit mechanism (400); The sliding mechanism (100) includes a slide rail base (110), a slider frame (120), a slider (130) and a slide rail (140); the slide rail (140) passes through the slide rail base ( 110) Installed on the vehicle body; the slider (130) and the slide rail (140) form a sliding pair; the slider frame (120) is fixed on the slider (130); The measuring mechanism (200) includes a rotary encoder (210), an encoder bracket (220) and a rotating rod (230); the rotary encoder (210) is installed on the slider frame ( 120); the rotary encoder (210) is connected to the horizontally arranged rotary rod (230); the rotary encoder (210) is installed vertically to collect the rotation angle of the rotary rod (230) on the horizontal plane and rotational angular velocity; the rotary encoder (210) is connected to the CAN bus of the vehicle; The rotating mechanism (300) includes a yoke (310), a bearing (320), and a rotating base (330). The rotating base (330) is installed on the steering knuckle (6), and the rotating base (330) and the bearing (320) adopts interference fit; the lower end of the yoke (310) is installed on the bearing (320); the upper end of the yoke (310) has two parallel bifurcations, and the bifurcations are provided with through grooves for The rotating rod (230) passes through horizontally, the rotating rod (230) slides freely in the through groove, and is constrained by the through groove to rotate in the horizontal direction; The limiting mechanism (400) includes a limiting rod (410), a limiting rod seat (420), a fixed seat one (430) and a fixed seat two (440); the fixed seat one (430) and the described The second fixed seat (440) forms an annular clamp, and the annular clamp is clamped on the shock absorber (5); the limit rod (410) is fixedly connected with the annular clamp through the limit rod seat (420); the A fork-shaped structure is arranged at the end of the limit rod (410), and the fork-shaped structure clamps the middle part of the fork arm (310). 2. A real-time measuring device for the actual wheel rotation angle according to claim 1, characterized in that a cylindrical plug is provided at the front end of the ring clamp, and a round hole is correspondingly provided on the limit rod seat (420), and the cylindrical plug Insert it into the round hole and fix it with fastening bolts.

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