Ackerman steering vehicle pose calculation method, system and equipment based on wheel speed odometer

Abstract

The invention relates to an Ackerman steering vehicle pose calculation method, system and equipment based on a wheel speed odometer. The method comprises the following steps: 1, calibrating the diameter of an Ackerman steering vehicle driving wheel; 2, simplifying an Ackerman steering vehicle motion model according to an Ackerman steering principle and a vehicle body kinematics principle; 3, calculating the speed of a driving wheel; 4, acquiring the acceleration of a driving wheel; 5, calculating the slippage rate of the driving wheel according to the Ackerman steering vehicle driving state; 6, acquiring a steering angle of a steering wheel of the Ackerman steering vehicle; 7, calculating the side slip angle of the centroid of the Ackerman steering vehicle; 8, the yaw angle of the Ackerman steering vehicle is obtained; 9, the yaw velocity of the Ackerman steering vehicle is calculated according to the side slip angle; 10, updating the speedometer according to a mileage correction formula; 11, the current pose of the Ackerman steering vehicle is obtained according to the speedometer updating value. When the mileage information is calculated according to the wheel speed, the influence of factors such as load and slip rate is fully considered, and high-precision vehicle attitude position information can be provided.

Description

TECHNICAL FIELD

[0001] The present application relates to the Ackerman steering vehicle pose calculation technical field, and particularly relates to an Ackerman steering vehicle pose calculation method, system and device based on a wheel speed odometer. BACKGROUND

[0002] The motion posture parameters of a vehicle mainly include the distance of the vehicle from the starting point and the angle turned by the vehicle relative to the starting point, etc. The ability of a vehicle to obtain its own posture parameters during driving is the basis for realizing vehicle motion planning and motion control. A global positioning system (GPS) can provide centimeter-level positioning accuracy, but the positioning accuracy of the global positioning system (GPS) depends on the strength of the satellite signal, and in places where the satellite signal is poor, the positioning accuracy cannot be guaranteed. Therefore, other sensors need to be used to perceive the surrounding environment, and then the motion posture of the vehicle is determined.

[0003] Currently, under the condition of satellite denial, a relatively mature solution is visual positioning. However, in the visual positioning system, the acceleration motion of the vehicle will cause the visual scale observability to be poor, resulting in reduced positioning accuracy. The wheel speed odometer calculates the motion posture of the vehicle through wheel speed, acceleration, steering angle and other information, and can provide absolute scale measurement, which can be used as an important means to compensate for the error of visual positioning. SUMMARY

[0004] The present application is directed to the deficiencies of the prior art, and proposes an Ackerman steering vehicle pose calculation method, system and device based on a wheel speed odometer.

[0005] One of the above-mentioned purposes of the present application is achieved by the following technical solution: An Ackerman steering vehicle pose calculation method based on a wheel speed odometer, comprising the following steps: S1: calibrating the diameter of the driving wheel of the Ackerman steering vehicle; S2: simplifying the Ackerman steering vehicle motion model according to the Ackerman steering principle and the kinematics principle of the vehicle body; S3: calculating the driving wheel speed; S4: obtaining the driving wheel acceleration; S5: calculating the driving wheel slip rate according to the driving state of the Ackerman steering vehicle; S6: obtaining the steering angle of the steering wheel of the Ackerman steering vehicle; S7: calculating the center of mass side slip angle of the Ackerman steering vehicle; S8: obtaining the yaw angle of the Ackerman steering vehicle; S9: calculating the yaw angular velocity of the Ackerman steering vehicle according to the center of mass side slip angle; S10: updating the odometer according to the mileage correction formula; S11: Based on the updated odometer values, determine the current position of the Ackerman-steered vehicle.

[0006] Furthermore, in step S1, the method for calibrating the diameter of the drive wheels of the Ackerman steering vehicle is as follows: when the Ackerman steering vehicle is fully loaded, control the linear motion of the Ackerman steering vehicle to make the drive wheels rotate. By circling the track and recording the distance traveled, the calibration diameter of the drive wheels can be determined; drive wheel calibration diameter It is calculated using the following formula:

[0007] In the formula, The calibration diameter for the drive wheel; The number of revolutions of the drive wheel; The distance traveled by the vehicle when Ackerman turned; The value is a constant, taking the value 3.14. The number of rotations of the drive wheel needs to be measured using an encoder. A program is written to record the encoder increment on the drive wheel. When the increment is reached, the motor is controlled to stop rotating.

[0008] Furthermore, in step S2, during the Ackerman steering process, the steering angles and steering speeds of the left and right steering wheels are not much different, and the rotational speeds of the left and right drive wheels are basically the same. According to the principle of symmetry, the simplified Ackerman steering vehicle motion model is as follows: the left and right steering wheels can be simplified to a single wheel, the left and right drive wheels can also be simplified to a single wheel, and the vehicle body is replaced by a rigid body.

[0009] Furthermore, in step S3, the drive wheel is... The wheel speed at any given time is calculated using the following formula:

[0010] In the formula, For the drive wheels in Wheel speed at any given moment, in units of ; For the motor in Output speed at any given time, in units of ; The calibration diameter of the drive wheel, in units of ; It is a constant, with a value of 3.14.

[0011] Furthermore, in step S4, the acceleration of the drive wheel is obtained by installing an acceleration sensor near the drive wheel.

[0012] Furthermore, in step S5, when the Ackermann steering vehicle is accelerating, the drive wheel slip ratio is calculated using the following recursive formula:

[0013] In the formula, When a vehicle with Ackermann steering accelerates, the drive wheels are... The slip ratio at any given time; When a vehicle with Ackermann steering accelerates, the drive wheels are... The slip ratio at any given time; For the drive wheels in Wheel speed at any given moment, in units of ; For the drive wheels in Wheel speed at any given moment, in units of ; For the drive wheels in acceleration at time t, in units of ; The time interval is expressed in units of 1 / 2. ; When the Ackermann steering vehicle is decelerating, the drive wheel slip ratio is calculated using the following recursive formula:

[0014] In the formula, When a vehicle using Ackermann steering decelerates, the drive wheels are... The slip ratio at any given time; When a vehicle using Ackermann steering decelerates, the drive wheels are... The slip ratio at any given time; For the drive wheels in Wheel speed at any given moment, in units of ; For the drive wheels in Wheel speed at any given moment, in units of ; For the drive wheels in acceleration at time t, in units of ; The time interval is expressed in units of 1 / 2. .

[0015] Furthermore, in step S6, the steering angle of the steering wheel is obtained by installing an angle sensor near the steering wheel.

[0016] Furthermore, in step S7, the sideslip angle of the Ackermann steering vehicle is calculated using the following formula:

[0017] In the formula, The sideslip angle of the center of gravity for an Ackermann steering vehicle, in degrees; For Ackermann to turn the vehicle in The steering angle of the steering wheel at any given moment, in degrees; The distance from the center of gravity of the Ackermann steering vehicle to the rear wheel, in units of... ; The distance from the center of gravity of the Ackermann steering vehicle to the front wheel, in units of .

[0018] Furthermore, in step S8, the yaw angle of the Ackerman steering vehicle is measured by a gyroscope mounted at the center of mass.

[0019] Furthermore, in step S9, the yaw rate of the Ackermann-steering vehicle is calculated using the following formula:

[0020] In the formula, For Ackermann to turn the vehicle in The yaw rate at time t, in units of ; For the drive wheels in Wheel speed at any given moment, in units of ; For Ackermann to turn the vehicle in The steering angle of the steering wheel at any given moment, in degrees; The distance from the center of gravity of the Ackermann steering vehicle to the rear wheel, in units of... ; The distance from the center of gravity of the Ackermann steering vehicle to the front wheel, in units of .

[0021] Furthermore, in step S10, when the Ackerman steering vehicle is accelerating, the odometer update formula is:

[0022] In the formula, In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; For Ackermann steering vehicle in the first The yaw angle at any given moment, in degrees; When a vehicle with Ackermann steering accelerates, the drive wheels are... The slip ratio at any given time; For the drive wheels in Wheel speed at any given moment, in units of ; The sideslip angle of the center of gravity for an Ackermann steering vehicle, in degrees; The time interval is expressed in units of 1 / 2. ; For Ackermann to turn the vehicle in The yaw rate at time t, in units of ; When the vehicle is decelerating during the Ackermann steering maneuver, the odometer update formula is:

[0023] In the formula, In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; For Ackermann steering vehicle in the first The yaw angle at any given moment, in degrees; When a vehicle using Ackermann steering decelerates, the drive wheels are... The slip ratio at any given time; For the drive wheels in Wheel speed at any given moment, in units of ; The sideslip angle of the center of gravity for an Ackermann steering vehicle, in degrees; The time interval is expressed in units of 1 / 2. ; For Ackermann to turn the vehicle in The yaw rate at time t, in units of .

[0024] The second objective of this invention is achieved through the following technical solution: A wheel-speed odometer-based Ackerman steering vehicle pose calculation system, used to implement the aforementioned wheel-speed odometer-based Ackerman steering vehicle pose calculation method, includes: Vehicle kinematics parameter acquisition module: The vehicle kinematics parameter acquisition module includes an acceleration sensor, an angle sensor, a gyroscope, and an encoder; the acceleration sensor is installed at the drive wheel of the Ackermann steering vehicle to acquire the acceleration of the drive wheel; the angle sensor is installed at the steering wheel of the Ackermann steering vehicle to acquire the steering angle of the steering wheel; the gyroscope is installed at the center of gravity of the Ackermann steering vehicle to acquire the yaw angle of the Ackermann steering vehicle; the encoder is installed at the drive wheel of the Ackermann steering vehicle to acquire the number of rotations of the drive wheel; Wheel calibration calculation module: used to measure the rotation of the drive wheels in an Ackermann steering vehicle. The distance traveled during the lap time is used to calibrate the diameter of the drive wheels of the Ackermann steering vehicle; Drive wheel slip ratio calculation module: This module is used to calculate the real-time slip ratio of the drive wheel based on the motor speed and drive wheel acceleration values. Ackermann steering vehicle center of gravity sideslip angle calculation module: It is used to calculate the center of gravity sideslip angle of Ackermann steering vehicles based on the values ​​returned by the angle sensors installed at the steering wheels and the vehicle body geometry. Ackermann steering vehicle yaw rate calculation module: Based on the motor speed and the values ​​returned by the angle sensor installed at the steering wheel, it can calculate the yaw rate of the Ackermann steering vehicle.

[0025] The third objective of this invention is achieved through the following technical solution: An electronic integrated device includes a domain controller, a computing module, a communication interface, a storage unit, and a communication bus. When the domain controller executes the program, it implements the steps of the Ackerman steering vehicle wheel speed odometer calculation method as described above.

[0026] The advantages and positive effects of this invention are as follows: (1) The method, system and device for calculating wheel speed odometer of Ackermann steering vehicle proposed in this invention takes into account the influence of tire deformation and slip rate during vehicle driving when calculating vehicle mileage by wheel speed. Compared with traditional wheel speed odometer, the accuracy is significantly improved.

[0027] (2) The method, system and device for calculating wheel speed odometer of Ackermann steering vehicle proposed in this invention simplify the vehicle body steering model by reasonably applying the principle of symmetry during the vehicle model establishment process, effectively reducing the number of parameters in the odometer update formula, making the measurement method simpler and more practical.

[0028] (3) The sensors required in the Ackerman steering vehicle wheel speed odometer calculation method, system and equipment proposed in this invention are mainly acceleration sensors, angle sensors, gyroscopes and encoders. They are inexpensive and technically mature and easy to obtain on the market. The required processor performance is not high. Most of the processors of the domain controllers on the market can meet the calculation requirements of this method. It is economical and suitable for widespread application. Attached Figure Description

[0029] Figure 1 This is a flowchart of a method for calculating wheel speed odometers for Ackermann steering vehicles proposed in this invention; Figure 2 This is a simplified result of the Ackermann steering vehicle kinematics model; Figure 3 This is a diagram showing the layout of the sensing sensors and computing modules on the Ackerman steering vehicle. In the diagram, 1-steering wheel; 2-drive wheel; 3-motor; 4-encoder; 5-accelerometer; 6-angle sensor; 7-wheel calibration calculation module; 8-drive wheel slip ratio calculation module; 9-Ackerman steering vehicle center of gravity sideslip angle calculation module; 10-Ackerman steering vehicle yaw rate calculation module; 11-gyroscope; Figure 4 This is a schematic diagram of the structure of an electronic device for calculating wheel speed and odometer of an Ackermann steering vehicle provided by the present invention; In the diagram, 101 is the communication bus; 102 is the domain controller; 103 is the computing module; 104 is the storage unit; and 105 is the communication interface. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. The following embodiments are used to illustrate this invention but cannot be used to limit the scope of this invention.

[0031] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0032] Example: Taking the direction of the driverless car as direction positive direction, The positive direction is the left turn direction for the driverless car. direction and The directions are perpendicular to each other. In this embodiment of the invention, the vehicle starts from a stationary state. For example, the mileage of a vehicle using Ackermann steering is calculated. Because the vehicle is in... The drive wheels are stationary at all times. Wheel speed at any moment The drive wheels are Slip rate at time Motor 3 in Output speed at any moment Ackermann's steering distance from the vehicle's center of gravity to the rear wheel. Ackermann's steering distance from the vehicle's center of gravity to the front wheels .

[0033] like Figure 1 As shown, a method for calculating the pose of an Ackerman steering vehicle based on wheel speed odometer is described. The method includes the following steps: S1: Calibrate the diameter of the drive wheels of the Ackermann steering vehicle; S2: Based on the Ackermann steering principle and vehicle kinematics principle, a simplified Ackermann steering vehicle motion model is constructed. S3: Calculate the speed of the drive wheels; S4: Obtain the acceleration of the drive wheels; S5: Calculate the drive wheel slip ratio based on the vehicle's driving state during Ackermann steering; S6: Obtain the steering angle of the steering wheels of an Ackermann steering vehicle; S7: Calculate the sideslip angle of the center of gravity of the Ackermann steering vehicle; S8: Obtain the yaw angle of the Ackermann steering vehicle; S9: Calculate the yaw rate of the Ackermann steering vehicle based on the sideslip angle of the center of gravity; S10: Update the odometer according to the mileage correction formula; S11: Based on the updated odometer values, determine the current position of the Ackerman-steered vehicle.

[0034] Specifically, step S1 includes: when the Ackermann steering vehicle is fully loaded, controlling the linear motion of the Ackermann steering vehicle to rotate the drive wheels. By circling the wheel and recording the distance traveled, the calibration diameter of the drive wheel can be determined. Drive wheel calibration diameter It is calculated using the following formula:

[0035] In the formula, The calibration diameter for the drive wheel; The number of revolutions of the drive wheel; The distance traveled by the vehicle when Ackerman turned; This is a constant, with a value of 3.14. The number of rotations of the drive wheel needs to be measured using an encoder. A program is written to record the encoder increment on the drive wheel, and when the increment is reached, the motor is controlled to stop rotating.

[0036] In this embodiment, when calibrating the drive wheel diameter, the drive wheel is controlled to rotate 10 times, and the travel distance of the Ackerman steering vehicle is measured to be 18.2 meters. drive wheel calibration diameter for:

[0037] Specifically, step S2 includes: During Ackerman steering, the steering angles and speeds of the left and right steering wheels are not significantly different, and the rotational speeds of the left and right drive wheels are basically consistent. Therefore, according to the principle of symmetry, the simplified Ackerman steering vehicle kinematic model is as follows: the left and right steering wheels can be simplified to a single wheel, the left and right drive wheels can also be simplified to a single wheel, and the vehicle body is replaced by a rigid body. The simplified Ackerman steering vehicle kinematic model is as follows: Figure 2 As shown.

[0038] Specifically, step S3 includes: the drive wheels in The wheel speed at any given time is calculated using the following formula:

[0039] In the formula, For the drive wheels in Wheel speed at any given moment, in units of ; For the motor in Output speed at any given time, in units of ; The calibration diameter of the drive wheel, in units of ; It is a constant, with a value of 3.14.

[0040] The motor is Output speed at any moment The drive wheel calibration diameter obtained in step S2 Therefore, the driving wheel can be calculated in The wheel speed at that moment is:

[0041] Specifically, step S4 includes: acquiring the acceleration of the drive wheel by installing an acceleration sensor near the drive wheel. In this embodiment, the acceleration of the drive wheel can be obtained from the acceleration sensor readings. acceleration at any moment .

[0042] Specifically, step S5 includes: when the Ackermann steering vehicle is accelerating, the drive wheel slip ratio is calculated using the following recursive formula:

[0043] In the formula, When a vehicle with Ackermann steering accelerates, the drive wheels are... The slip ratio at any given time; When a vehicle with Ackermann steering accelerates, the drive wheels are... The slip ratio at any given time; For the drive wheels in Wheel speed at any given moment, in units of ; For the drive wheels in Wheel speed at any given moment, in units of ; For the drive wheels in acceleration at time t, in units of ; The time interval is expressed in units of 1 / 2. .

[0044] When the Ackermann steering vehicle is decelerating, the drive wheel slip ratio is calculated using the following recursive formula:

[0045] In the formula, When a vehicle using Ackermann steering decelerates, the drive wheels are... The slip ratio at any given time; When a vehicle using Ackermann steering decelerates, the drive wheels are... The slip ratio at any given time; For the drive wheels in Wheel speed at any given moment, in units of ; For the drive wheels in Wheel speed at any given moment, in units of ; For the drive wheels in acceleration at time t, in units of ; The time interval is expressed in units of 1 / 2. .

[0046] In this embodiment, the Ackerman steering vehicle is in Since it is constantly accelerating, the slip ratio of the drive wheels is:

[0047] Specifically, step S6 includes: acquiring the steering wheel angle by installing an angle sensor near the steering wheel. Based on the measurement from the angle sensor, the Ackerman steering vehicle... Steering wheel angle at any moment .

[0048] Specifically, step S7 includes: the sideslip angle of the Ackermann steering vehicle is calculated using the following formula:

[0049] In the formula, The sideslip angle of the center of gravity for an Ackermann steering vehicle, in degrees; For Ackermann to turn the vehicle in The steering angle of the steering wheel at any given moment, in degrees; The distance from the center of gravity of the Ackermann steering vehicle to the rear wheel, in units of... ; The distance from the center of gravity of the Ackermann steering vehicle to the front wheel, in units of .

[0050] Based on the distance from the vehicle's center of gravity to the rear wheel when Ackerman steering. Ackermann's steering distance from the vehicle's center of gravity to the front wheels Ackerman turned the vehicle in Steering wheel angle at any moment The sideslip angle of the center of gravity of the Ackermann steering vehicle can be obtained. :

[0051] Specifically, step S8 includes: the yaw angle of the Ackerman steering vehicle is measured by a gyroscope mounted at the center of gravity. Based on the gyroscope measurement, in the first... Yaw angle of driverless cars .

[0052] Specifically, step S9 includes: the yaw rate of the Ackermann steering vehicle is calculated using the following formula:

[0053] In the formula, For Ackermann to turn the vehicle in The yaw rate at time t, in units of ; For the drive wheels in Wheel speed at any given moment, in units of ; For Ackermann to turn the vehicle in The steering angle of the steering wheel at any given moment, in degrees; The distance from the center of gravity of the Ackermann steering vehicle to the rear wheel, in units of... ; The distance from the center of gravity of the Ackermann steering vehicle to the front wheel, in units of .

[0054] Based on the distance from the vehicle's center of gravity to the rear wheel when Ackerman steering. Ackermann's steering distance from the vehicle's center of gravity to the front wheels Ackerman turned the vehicle in Steering wheel angle at any moment The drive wheels are Wheel speed at any moment The yaw rate of the Ackermann steering vehicle can be obtained as follows:

[0055] Specifically, step S10 includes: when the Ackerman steering vehicle is accelerating, the odometer update formula is:

[0056] In the formula, In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; For Ackermann steering vehicle in the first The yaw angle at any given moment, in degrees; When a vehicle with Ackermann steering accelerates, the drive wheels are... The slip ratio at any given time; For the drive wheels in Wheel speed at any given moment, in units of ; The sideslip angle of the center of gravity for an Ackermann steering vehicle, in degrees; The time interval is expressed in units of 1 / 2. ; For Ackermann to turn the vehicle in The yaw rate at time t, in units of .

[0057] When the vehicle is decelerating during the Ackermann steering maneuver, the odometer update formula is:

[0058] In the formula, In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; For Ackermann steering vehicle in the first The yaw angle at any given moment, in degrees; When a vehicle using Ackermann steering decelerates, the drive wheels are... The slip ratio at any given time; For the drive wheels in Wheel speed at any given moment, in units of ; The sideslip angle of the center of gravity for an Ackermann steering vehicle, in degrees; The time interval is expressed in units of 1 / 2. ; For Ackermann to turn the vehicle in The yaw rate at time t, in units of In this embodiment, the Ackerman steering vehicle is in an accelerating state, and the odometer update formula is:

[0059] In summary, based on the odometer update results, the current pose of the Ackerman-steering vehicle can be determined. This embodiment of the invention is described in the [number missing] section. time compared to the first time( ), The displacement in the direction is 10.031. , The displacement in the direction is 0.06. The yaw angle changed by 0.39°.

[0060] A wheel-speed odometer-based Ackerman steering vehicle pose calculation system, used to implement the aforementioned wheel-speed odometer-based Ackerman steering vehicle pose calculation method, includes: Vehicle kinematics parameter acquisition module: The vehicle kinematics parameter acquisition module includes an acceleration sensor 5, an angle sensor 6, a gyroscope 11, and an encoder 4; the acceleration sensor is installed at the drive wheel 2 of the Ackermann steering vehicle to acquire the acceleration of the drive wheel; the angle sensor is installed at the steering wheel 1 of the Ackermann steering vehicle to acquire the steering angle of the steering wheel; the gyroscope is installed at the center of gravity of the Ackermann steering vehicle to acquire the yaw angle of the Ackermann steering vehicle; the encoder is installed at the drive wheel of the Ackermann steering vehicle to acquire the number of rotations of the drive wheel; Wheel calibration calculation module 7: used to measure the rotation of the drive wheels of an Ackermann steering vehicle. The travel distance during the lap time is used to calibrate the diameter of the drive wheels of the Ackermann steering vehicle.

[0061] Drive wheel slip ratio calculation module 8: It is used to calculate the real-time slip ratio of the drive wheel based on the motor speed and drive wheel acceleration values.

[0062] Ackermann steering vehicle center of gravity sideslip angle calculation module 9: It is used to calculate the sideslip angle of Ackermann steering vehicles based on the values ​​returned by the angle sensors installed at the steering wheels and the vehicle body geometry.

[0063] Ackermann steering vehicle yaw rate calculation module 10: It is used to calculate the yaw rate of Ackermann steering vehicles based on the motor speed and the values ​​returned by the angle sensor installed at the steering wheel.

[0064] like Figure 4As shown, an electronic integrated device mainly includes: a communication bus 101, a domain controller 102, a computing module 103, a storage unit 104, and a communication interface 105. The domain controller 102, computing module 103, storage unit 104, and communication interface 105 communicate with each other via the communication bus 101. The domain controller 102 can invoke the computing module 103 and storage unit 104 to execute the aforementioned Ackerman steering vehicle pose calculation method based on wheel speed odometer.

[0065] Furthermore, when the instructions in storage unit 104 can be implemented as software functional units, they can be stored in a domain controller-readable storage medium. Storage media include external hard drives, recordable optical discs, USB flash drives, and flash memory cards, etc.

[0066] The method, system, and device for calculating wheel speed and odometer of Ackermann steering vehicles described in this invention are not limited to the specific embodiments described above. Those skilled in the art can implement this invention using various other specific embodiments based on the disclosed content of the embodiments and accompanying drawings. Therefore, any design that adopts the design structure and concept of this invention and makes some simple changes or modifications falls within the protection scope of this invention.

Claims

1. A method for calculating the pose of an Ackerman steering vehicle based on wheel speed odometer, characterized in that, Includes the following steps: S1: Calibrate the diameter of the drive wheels of the Ackermann steering vehicle; S2: Based on the Ackermann steering principle and vehicle kinematics principle, a simplified Ackermann steering vehicle motion model is constructed. S3: Calculate the speed of the drive wheels; S4: Obtain the acceleration of the drive wheels; S5: Calculate the drive wheel slip ratio based on the vehicle's driving state during Ackermann steering; S6: Obtain the steering angle of the steering wheels of an Ackermann steering vehicle; S7: Calculate the sideslip angle of the center of gravity of the Ackermann steering vehicle; S8: Obtain the yaw angle of the Ackermann steering vehicle; S9: Calculate the yaw rate of the Ackermann steering vehicle based on the sideslip angle of the center of gravity; S10: Update the odometer according to the mileage correction formula; S11: Based on the updated odometer values, determine the current position of the Ackerman-steered vehicle.

2. The method for calculating the pose of an Ackerman steering vehicle based on wheel speed odometer according to claim 1, characterized in that: In step S1, the method for calibrating the diameter of the drive wheels of the Ackerman steering vehicle is as follows: when the Ackerman steering vehicle is fully loaded, control the linear motion of the Ackerman steering vehicle to make the drive wheels rotate. By circling the track and recording the distance traveled, the calibration diameter of the drive wheels can be determined; drive wheel calibration diameter It is calculated using the following formula: ; In the formula, The calibration diameter for the drive wheel; The number of revolutions of the drive wheel; The distance traveled by the vehicle when Ackerman turned; The value is a constant, taking the value 3.

14. The number of rotations of the drive wheel needs to be measured using an encoder. A program is written to record the encoder increment on the drive wheel. When the increment is reached, the motor is controlled to stop rotating.

3. The method for calculating the pose of an Ackerman steering vehicle based on wheel speed odometer according to claim 1, characterized in that: In step S2, during the Ackerman steering process, the steering angles and steering speeds of the left and right steering wheels are not much different, and the rotational speeds of the left and right drive wheels are basically the same. According to the principle of symmetry, the simplified Ackerman steering vehicle motion model is as follows: the left and right steering wheels can be simplified to one wheel, the left and right drive wheels can also be simplified to one wheel, and the vehicle body is replaced by a rigid body.

4. The method for calculating the pose of an Ackerman steering vehicle based on wheel speed odometer according to claim 1, characterized in that: In step S3, the drive wheel is The wheel speed at any given time is calculated using the following formula: ; In the formula, For the drive wheels in Wheel speed at any given time, in units of ; For the motor in Output speed at any given time, in units of ; The calibration diameter of the drive wheel, in units of ; It is a constant, with a value of 3.

14.

5. The method for calculating the pose of an Ackerman steering vehicle based on wheel speed odometer according to claim 1, characterized in that: In step S4, the acceleration of the drive wheel is obtained by installing an acceleration sensor near the drive wheel.

6. The method for calculating the pose of an Ackerman steering vehicle based on wheel speed odometer according to claim 1, characterized in that: In step S5, when the Ackermann steering vehicle is accelerating, the drive wheel slip ratio is calculated using the following recursive formula: ; In the formula, When a vehicle with Ackermann steering accelerates, the drive wheels are... The slip ratio at any given time; When a vehicle with Ackermann steering accelerates, the drive wheels are... The slip ratio at any given time; For the drive wheels in Wheel speed at any given time, in units of ; For the drive wheels in Wheel speed at any given time, in units of ; For the drive wheels in acceleration at time t, in units of ; The time interval is expressed in units of 1 / 2. ; When the Ackermann steering vehicle is decelerating, the drive wheel slip ratio is calculated using the following recursive formula: ; In the formula, When a vehicle using Ackermann steering decelerates, the drive wheels are... The slip ratio at any given time; When a vehicle using Ackermann steering decelerates, the drive wheels are... The slip ratio at any given time; For the drive wheels in Wheel speed at any given time, in units of ; For the drive wheels in Wheel speed at any given time, in units of ; For the drive wheels in acceleration at time t, in units of ; The time interval is expressed in units of 1 / 2. .

7. The method for calculating the pose of an Ackerman steering vehicle based on wheel speed odometer according to claim 1, characterized in that: In step S6, the steering angle of the steering wheel is obtained by installing an angle sensor near the steering wheel.

8. The method for calculating the pose of an Ackerman steering vehicle based on wheel speed odometer according to claim 1, characterized in that: In step S7, the sideslip angle of the Ackermann steering vehicle is calculated using the following formula: ; In the formula, The sideslip angle of the center of gravity for an Ackermann steering vehicle, in degrees; For Ackermann to turn the vehicle in The steering angle of the steering wheel at any given moment, in degrees; The distance from the center of gravity of the Ackermann steering vehicle to the rear wheel, in units of... ; The distance from the center of gravity of the Ackermann steering vehicle to the front wheel, in units of .

9. The method for calculating the pose of an Ackerman steering vehicle based on wheel speed odometer according to claim 1, characterized in that: In step S8, the yaw angle of the Ackerman steering vehicle is measured by a gyroscope installed at the center of mass.

10. The method for calculating the pose of an Ackerman steering vehicle based on wheel speed odometer according to claim 1, characterized in that: In step S9, the yaw rate of the Ackermann steering vehicle is calculated using the following formula: ; In the formula, For Ackermann to turn the vehicle in The yaw rate at time t, in units of ; For the drive wheels in Wheel speed at any given time, in units of ; For Ackermann to turn the vehicle in The steering angle of the steering wheel at any given moment, in degrees; The distance from the center of gravity of the Ackermann steering vehicle to the rear wheel, in units of... ; The distance from the center of gravity of the Ackermann steering vehicle to the front wheel, in units of .

11. The method for calculating the pose of an Ackerman steering vehicle based on wheel speed odometer according to claim 1, characterized in that: In step S10, when the Ackerman steering vehicle is accelerating, the odometer update formula is: ; In the formula, In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; For Ackermann steering vehicle in the first The yaw angle at any given moment, in degrees; When a vehicle with Ackermann steering accelerates, the drive wheels are... The slip ratio at any given time; For the drive wheels in Wheel speed at any given time, in units of ; The sideslip angle of the center of gravity for an Ackermann steering vehicle, in degrees; The time interval is expressed in units of 1 / 2. ; For Ackermann to turn the vehicle in The yaw rate at time t, in units of ; When the vehicle is decelerating during the Ackermann steering maneuver, the odometer update formula is: ; In the formula, In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; In the first At the moment Ackerman turned the vehicle at Displacement in the direction, in units of ; For Ackermann steering vehicle in the first The yaw angle at any given moment, in degrees; When a vehicle using Ackermann steering decelerates, the drive wheels are... The slip ratio at any given time; For the drive wheels in Wheel speed at any given time, in units of ; The sideslip angle of the center of gravity for an Ackermann steering vehicle, in degrees; The time interval is expressed in units of 1 / 2. ; For Ackermann to turn the vehicle in The yaw rate at time t, in units of .

12. A vehicle pose calculation system based on wheel speed odometer for Ackerman steering, characterized in that: The method for calculating the pose of an Ackerman steering vehicle based on wheel speed odometer as described in any one of claims 1-10 includes: Vehicle kinematics parameter acquisition module: The vehicle kinematics parameter acquisition module includes an acceleration sensor, an angle sensor, a gyroscope, and an encoder; the acceleration sensor is installed at the drive wheel of the Ackermann steering vehicle to acquire the acceleration of the drive wheel; the angle sensor is installed at the steering wheel of the Ackermann steering vehicle to acquire the steering angle of the steering wheel; the gyroscope is installed at the center of gravity of the Ackermann steering vehicle to acquire the yaw angle of the Ackermann steering vehicle; the encoder is installed at the drive wheel of the Ackermann steering vehicle to acquire the number of rotations of the drive wheel; Wheel calibration calculation module: used to measure the rotation of the drive wheels in an Ackermann steering vehicle. The distance traveled during the lap time is used to calibrate the diameter of the drive wheels of the Ackermann steering vehicle; Drive wheel slip ratio calculation module: This module is used to calculate the real-time slip ratio of the drive wheel based on the motor speed and drive wheel acceleration values. Ackermann steering vehicle center of gravity sideslip angle calculation module: It is used to calculate the center of gravity sideslip angle of Ackermann steering vehicles based on the values ​​returned by the angle sensors installed at the steering wheels and the vehicle body geometry. Ackermann steering vehicle yaw rate calculation module: Based on the motor speed and the values ​​returned by the angle sensor installed at the steering wheel, it can calculate the yaw rate of the Ackermann steering vehicle.

13. An electronic integrated device, comprising a domain controller, a computing module, a communication interface, a storage unit, and a communication bus, wherein the domain controller, when executing the program, implements the steps of the Ackerman steering vehicle wheel speed odometer calculation method as described above.

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