A method for measuring vehicle rotation angle based on electronic gyroscope

Abstract

The present invention discloses a method for measuring vehicle turning angles based on an electronic gyroscope. When measuring a whole vehicle, the front wheel of the vehicle is parked between two rollers of a floating plate. The floating plate enables the front wheel to be centered, rolled, swung back and forth, and rotated clockwise and counterclockwise. A rolling ball allows the upper half of the floating plate to move freely within the X-Y axis limits. The rollers are used to position the vehicle tires, and a lifting device is used to push the tires out of the roller sleeves to facilitate the vehicle's departure from the measuring platform. The present invention utilizes the principle of measuring spatial turning angles using an electronic gyroscope to address various measurement errors that exist when measuring turning angles on a vehicle inspection platform. The turning angle measurement device has the characteristics of good adaptability, high accuracy, and ease of use, making it suitable for use in vehicle factory inspections.

Description

Technical Field

[0001] The invention relates to a method for measuring an automobile rotation angle based on an electronic gyroscope, and belongs to the technical field of automobile measurement. Background Art

[0002] According to the applicant's understanding, traditional automobile steering angle measurement generally uses a high-precision potentiometer or encoder for measurement. The measurement principle is that the rotation angle of the wheel is consistent with the rotation angle of the center of the floating plate. The basis of this measurement method is that the center of the turntable and the wheel need to overlap. When the centers do not overlap (which can easily happen, such as when the vehicle is parked incorrectly, slipping in rainy days, etc.), a certain error will occur. Summary of the Invention

[0003] The purpose of the present invention is to solve the problems existing in the prior art and to propose a method for measuring the rotation angle of a car based on an electronic gyroscope, which has accurate measurement data, good repeatability and is easy to use.

[0004] The specific technical solution of the present invention is as follows: a method for measuring the turning angle of a car based on an electronic gyroscope, characterized by comprising a floating plate, an electronic gyroscope, an industrial computer and a workstation display screen arranged on the industrial computer; the industrial computer is arranged on the left front of the entire device;

[0005] The floating plate is fixed on the positions of the four wheels of the vehicle respectively, and the electronic gyroscope is installed on the rotating wheel at the bottom of the floating plate; when measuring the whole vehicle, the front wheel of the vehicle is parked in the middle of the two rollers of the floating plate, and the floating plate is used to realize the centering, rolling, front and rear swinging, left and right swinging, clockwise and counterclockwise rotation of the front wheel of the vehicle; the floating plate is composed of two parts, the upper and lower parts, which are installed as a whole in the bottom frame, and the lower part is fixed with a rolling ball and a locking mechanism; the upper part includes a base plate, a roller installed on the base plate and a lifting device; the upper half of the floating plate is allowed to move freely within the XY axis limit range through the rolling ball, the roller is used to position the car tire, and the lifting device is used to push the car tire out of the roller sleeve to facilitate the car to leave the measuring platform.

[0006] Furthermore, the following specific steps are included:

[0007] Step 1: Drive the vehicle to be tested onto the measuring floating plate and ensure that the front wheels of the vehicle are located between the two rollers;

[0008] Step 2: After the vehicle arrives and the vehicle number is entered on the industrial computer, the angle measurement software in the industrial computer will automatically reset to zero;

[0009] Step 3: The driver turns the steering wheel to the maximum steering angle according to the prompts on the industrial computer display screen. The floating plate rotates under the drive of the wheel, and the electronic gyroscope records the spatial angle data of its own rotation.

[0010] Step 4: After software calculation, the angle of the gyroscope on the plane perpendicular to the ground is obtained. This angle is the steering angle of the vehicle. The software interface can realize data calibration and serial port settings.

[0011] Furthermore, during the steering process, the center axis of the vehicle and the center axis of the equipment generate an angle θ1 = Arc tan (Δy / D), where Δy is the vehicle's y-axis offset and D is the vehicle's wheelbase.

[0012] The deviation angle caused by the non-fixed axis rotation of the floating plate during the measurement process Where Δx is the vehicle's x-axis offset, and H0 is the height from the sensor to the bottom of the tire.

[0013] During the measurement process, the sliding angle θ3 between the tire and the floating plate and the transmission error θ4 between the steering wheel and the steering gear are equal to kΔβ, where K is the angle coefficient and Δβ is the steering gear error.

[0014] Total system measurement error:

[0015] Further analysis of the impact of θ1 on the measured value shows that the main influences are the vehicle wheelbase and the Y-axis offset during measurement. The larger the vehicle wheelbase, the smaller the impact, and the larger the vehicle Y-axis offset, the greater the resulting deviation. For our commonly used vehicle models with a wheelbase of 2800mm and a maximum Y-axis offset of the floating plate of ±15mm, the theoretical deviation range of θ1 is -0.31°≤θ1≤0.31°.

[0016] Furthermore, we quantitatively analyze the magnitude of θ2. H0 is determined during equipment design; the larger this height, the smaller θ2. During measurement, both X- and Y-axis offsets occur simultaneously. Looking at the floating plate parameters, H0 = 326mm. The allowable Y-axis offset is ±15mm, and the maximum X-axis offset is 62mm. Substituting this into the formula, we obtain -2.6° ≤ θ2 ≤ 2.6°. The X-axis offset has little impact on the overall value, contributing approximately 0.1°.

[0017] Furthermore, the contribution of θ4 generally comes from factors such as the clearance generated in the steering gear and the misalignment of the steering wheel, and θ4 = kΔβ.

[0018] The calculation formula shows that θ1 and θ2 have the same sign, so these two values ​​are combined to define the offset error θoffset. This value ranges from -2.91° ≤ θoffset ≤ 2.91°, making it the primary factor. Correspondingly, θ3 and θ4 have an overall influence of 0.6°, making them secondary factors and not significantly related to the floating disk.

[0019] When testing the angle of rotation of a floating disk, fixed-axis rotation cannot be achieved, which inevitably results in Δx and Δy. Δy, in particular, has a significant impact on the angle measurement. To avoid this error, optimization of the measurement sensor can be considered. Currently, conventional sensors include potentiometers and encoders. These sensors correspond to different measured values ​​as the shaft rotates, and the difference is the angle value. However, Δy also produces this measurement difference, resulting in the error analyzed above. To eliminate this measurement error, an electronic gyroscope is used for angle measurement. This sensor measures angular momentum and uses a single-chip microcomputer for integration to obtain the angle value of the object's rotation. This measured value is independent of Δy, eliminating the measurement deviation of Δy.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: the automobile angle measurement method based on the electronic gyroscope of the present invention can eliminate measurement errors and solve the problem that the original measurement method will produce a certain measurement angle when the floating plate moves back and forth or left and right (not rotating), and the sensor cannot identify whether the angle is an error value. The angle error value is random, resulting in a large error in the measurement value. The present invention utilizes the principle of measuring spatial angles with an electronic gyroscope to solve various measurement errors that exist when measuring angles on an automobile inspection platform. The angle measurement device has the characteristics of good adaptability, high precision, and ease of use, and is suitable for use in factory inspection of automobiles by automobile manufacturers. At the same time, the present invention uses a new type of gyroscope sensor that does not need to be installed at the center of the angle sliding plate, which also reduces mechanical and cumulative errors.

[0021] The present invention features intelligent inspection process guidance and a real-time, dynamic graphical interface, enabling quick and convenient completion of the entire inspection process. Upon completion, data is automatically stored in a local database powered by Microsoft SQL Server 2008, offering high storage capacity and exceptional security. The present measurement system can be integrated into existing inspection line networking systems, enabling access to and printing of inspection data, seamlessly integrating with existing systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be further described below with reference to the accompanying drawings.

[0023] Figure 1 It is a structural schematic diagram of the floating plate of the present invention.

[0024] Figure 2 This is a diagram showing the internal structure of the floating plate of the present invention.

[0025] Figure 3 It is a top view of the floating plate of the present invention.

[0026] Figure 4 It is a flowchart of the present invention.

[0027] Figure 5 This is a schematic diagram of the vehicle measurement of the present invention. DETAILED DESCRIPTION

[0028] Example

[0029] This embodiment provides a method for measuring the turning angle of a car based on an electronic gyroscope. The structure of the method is shown in the figure, and includes a floating plate 1, an electronic gyroscope 2, an industrial computer 3, and a workstation display screen 4 arranged on the industrial computer, wherein the industrial computer is arranged on the left front of the entire device.

[0030] There are four sets of floating plates, each fixed to the position of the vehicle's four wheels. Among them, the electronic gyroscope is bolted to a metal base set on the rotating wheel at the bottom of the floating plate, which is consistent with the rotation angle of the floating plate.

[0031] The floating plate consists of two parts, upper and lower, mounted integrally within a frame 5. The lower portion of the floating plate is secured with a ball bearing 6 and a locking mechanism 7, and is held in position by a limit bearing 9 mounted within a limit frame 8. The upper portion of the floating plate comprises a base plate, rollers mounted on the base plate, and a lifting mechanism. The rollers consist of a symmetrically arranged free roller 10 and a motor roller 11, both mounted to the base plate via a fixed pressure plate 12 and secured in position by end stops 13. A lifting mechanism 14 is mounted between the free roller and the motor roller. A bracket 15 is also mounted at the bottom of the frame.

[0032] When measuring the entire vehicle, the front wheel of the vehicle is parked between the two rollers of the floating plate. The floating plate is used to realize the centering, rolling, front and rear swinging, left and right swinging, and clockwise and counterclockwise rotation of the vehicle's front wheel; the upper part of the floating plate is allowed to move freely within the XY axis limit range through the rolling ball. The roller is used to position the car tire, and the lifting device is used to push the car tire out of the roller sleeve to facilitate the car to leave the measuring platform.

[0033] The measurement method of this embodiment includes the following steps:

[0034] Step 1: Drive the vehicle to be tested onto the measuring float and ensure that the front wheels of the vehicle are between the two rollers.

[0035] Step 2: After the vehicle arrives and the vehicle number is entered on the industrial computer, the angle measurement software in the industrial computer will automatically reset to zero.

[0036] Step 3: The driver turns the steering wheel to the maximum steering angle according to the instructions on the industrial computer's display. The floating plate rotates under the influence of the wheel, and the electronic gyroscope records its spatial angle data. This electronic gyroscope uses a high-performance microprocessor and advanced dynamics solver and Kalman dynamic filtering algorithms to quickly determine the module's current real-time motion posture, including spatial angle change and spatial angular acceleration. The microprocessor outputs the spatial angle change value via a TTL or RS232 serial port.

[0037] Step 4: Software calculations are performed to obtain the angle the gyroscope rotates on a plane perpendicular to the ground. This angle is the vehicle's steering angle. The software interface allows for data calibration and is configured using a serial port. The host computer program obtains the microprocessor's spatial angle change value via TTL level measurement or RS232 serial port, selects a fixed XY plane (other planes are similar), and calculates the change in the Z-axis angle. An arbitrary state value is selected as the zero point, with counterclockwise deflection being a negative angle and clockwise deflection being a positive angle. The maximum value of the angle change during the deflection process is selected as the final measurement value to obtain the maximum deflection of the vehicle's wheel angle. The left and right wheel sensors measure the maximum left and right turns, respectively.

[0038] During the steering process, the center axis of the vehicle and the center axis of the equipment generate an angle θ1 = Arc tan (Δy / D), where Δy is the vehicle's y-axis offset and D is the vehicle's wheelbase.

[0039] The deviation angle caused by the non-fixed axis rotation of the floating plate during the measurement process Where Δx is the vehicle's x-axis offset, and H0 is the height from the sensor to the bottom of the tire.

[0040] During the measurement process, the sliding angle θ3 between the tire and the floating plate and the transmission error θ4 between the steering wheel and the steering gear are equal to kΔβ, where K is the angle coefficient and Δβ is the steering gear error.

[0041] Total system measurement error:

[0042] Analyzing the influence of θ1 on the measured value, the main influences are the vehicle wheelbase and the Y-axis offset during measurement. The larger the vehicle wheelbase, the smaller the influence. The larger the vehicle Y-axis offset, the greater the deviation. For our commonly used vehicle with a wheelbase of 2800mm and a floating plate Y-axis limit offset of ±15mm, the theoretical deviation range of θ1 is -0.31°≤θ1≤0.31°.

[0043] Quantitative analysis of the value of θ2: H0 is determined during equipment design. The greater the height, the smaller θ2. During measurement, the X-axis and Y-axis offsets occur simultaneously. Checking the floating plate parameters, H0 = 326mm, the allowable Y-axis offset is ±15mm, and the maximum X-axis offset is 62mm. Substituting this into the formula, -2.6°≤θ2≤2.6°. The X-axis offset has little effect on the overall value, contributing approximately 0.1°.

[0044] The contribution of θ4 generally comes from factors such as the clearance generated in the steering gear and the misalignment of the steering wheel, and θ4 = kΔβ.

[0045] The calculation formula shows that θ1 and θ2 have the same sign, so these two values ​​are combined to define the offset error θoffset. This value ranges from -2.91° ≤ θoffset ≤ 2.91°, making it the primary factor. Correspondingly, θ3 and θ4 have an overall influence of 0.6°, making them secondary factors and not significantly related to the floating disk.

[0046] When testing the angle of a floating disk, fixed-axis rotation is not possible, inevitably resulting in Δx and Δy. Δy, in particular, significantly affects the angle measurement. To avoid this error, optimization of the measurement sensor can be considered. Currently, conventional sensors, such as potentiometers and encoders, produce different measured values ​​as the shaft rotates, and the difference represents the angle. However, this measurement difference also occurs in Δy, resulting in the error discussed above. To eliminate this measurement error, an electronic gyroscope is used for angle measurement. This sensor measures angular momentum, and a microcontroller performs integration calculations to obtain the angle of rotation. This calculated value is independent of Δy, eliminating the measurement bias associated with Δy.

[0047] In addition to the above examples, the present invention may also have other implementations. Any technical solution formed by equivalent replacement or equivalent transformation falls within the scope of protection of this claim.

Claims

1. A method for measuring the rotation angle of a vehicle based on an electronic gyroscope, characterized in that: The operation is performed through a vehicle turning angle measurement system, which includes a floating plate, an electronic gyroscope, an industrial computer, and a workstation display screen arranged on the industrial computer; the industrial computer is arranged on the left front of the entire device; The floating plate is fixed to the positions of the four wheels of the vehicle, and the electronic gyroscope is installed on the rotating wheel at the bottom of the floating plate. When measuring the entire vehicle, the front wheel of the vehicle is parked between the two rollers of the floating plate, and the floating plate is used to realize the centering, rolling, front and rear swinging, left and right swinging, clockwise and counterclockwise rotation of the front wheel of the vehicle. The floating plate is composed of two parts, upper and lower, which are installed as a whole in the bottom frame. The lower part is fixed with a rolling ball and a locking mechanism; the upper part includes a base plate, a roller installed on the base plate, and a lifting device. The upper half of the floating plate is allowed to move freely within the XY axis limit range by the rolling ball. The roller is used to position the car tire, and the lifting device is used to push the car tire out of the roller sleeve to facilitate the car to leave the measuring platform. The specific steps include: Step 1: Drive the vehicle to be tested onto the measuring floating plate and ensure that the front wheels of the vehicle are located between the two rollers; Step 2: After the vehicle arrives and the vehicle number is entered on the industrial computer, the angle measurement software in the industrial computer will automatically reset to zero; Step 3: The driver turns the steering wheel to the maximum steering angle according to the prompts on the industrial computer display screen. The floating plate rotates under the drive of the wheel, and the electronic gyroscope records the spatial angle data of its own rotation. Step 4: After software calculation, the angle of the gyroscope on the plane perpendicular to the ground is obtained. This angle is the steering angle of the vehicle. The software interface implements data calibration and serial port settings; During the steering process, the center axis of the vehicle and the center axis of the equipment generate an angle θ1 = Arc tan (Δy / D), where Δy is the vehicle's y-axis offset and D is the vehicle's wheelbase. The deviation angle caused by the non-fixed axis rotation of the floating plate during the measurement process Where Δx is the vehicle’s x-axis offset, and H0 is the height from the sensor to the bottom of the tire. During the measurement process, the sliding angle θ3 between the tire and the floating plate and the transmission error θ4 between the steering wheel and the steering gear are equal to kΔβ, where K is the angle coefficient and Δβ is the steering gear error. Total system measurement error: Analyze the impact of θ1 on the measured value: the vehicle wheelbase and the Y-axis offset during measurement. The larger the vehicle wheelbase, the smaller the impact. The larger the vehicle Y-axis offset, the greater the resulting deviation. Assuming a commonly used vehicle with a wheelbase of 2800mm and a floating plate Y-axis limit offset of ±15mm, the theoretical deviation range of θ1 is -0.31°≤θ1≤0.31°. Quantitatively analyze the size of θ2. H0 is determined during equipment design. The larger H0 is, the smaller θ2 is. During measurement, the X-axis and Y-axis offsets occur simultaneously. Check the floating plate parameters, H0 = 326mm, the allowable Y-axis offset is ±15mm, and the maximum X-axis offset is 62mm. Substituting into the formula, -2.6°≤θ2≤2.6°; the X-axis offset has little effect on the overall value, with a contribution of 0.1°.

2. The method for measuring vehicle rotation angle based on an electronic gyroscope according to claim 1, wherein: The electronic gyroscope is bolted to a metal base that is aligned with the rotation angle of the floating disk.

3. The method for measuring vehicle rotation angle based on an electronic gyroscope according to claim 1, wherein: The contribution of θ4 comes from the clearance in the steering gear and the misalignment of the steering wheel, θ4 = kΔβ; From the calculation formula, we know that θ1 and θ2 have the same sign, so these two values ​​are combined to define the offset error θ offset. The range of this value is -2.91°≤θ offset≤2.91°, which is the main factor. Correspondingly, the overall influence of θ3 and θ4 is 0.6°, which is a minor factor and has little to do with the floating plate. When the floating disk is performing an angle test, fixed-axis rotation cannot be achieved, and Δx and Δy will inevitably be generated, especially Δy, which has a greater impact on the measurement of the angle. This error should be avoided and the measurement sensor should be optimized. At this stage, conventional sensors are potentiometers and encoders. When the shaft rotates, different measurement values ​​correspond to different values, and the difference is the angle value; but Δy will also produce this measurement difference, resulting in the error value analyzed above; to eliminate this measurement error, an electronic gyroscope is used for angle measurement. This sensor measures angular momentum and uses a single-chip microcomputer for integration calculation to obtain the angle value of the object's rotation. This measured calculated value is independent of Δy, which can eliminate the measurement deviation of Δy.

Images