Differential unmanned vehicle space attitude estimation method, system and device based on slip rate correction

Abstract

The invention relates to the technical field of unmanned parking space attitude estimation, and provides a differential unmanned parking space attitude estimation method, system and device based on slip rate correction. Comprising the following steps: simplifying a differential unmanned vehicle kinematics model according to a vehicle motion principle; acquiring accelerations and speeds of left and right wheels; calculating a tire slip rate according to the acceleration and speed of the left and right wheels and a differential unmanned vehicle kinematics model; obtaining a pose angle of the vehicle by using a gyroscope; judging whether the acceleration difference of the left and right wheels is greater than a threshold value or not, and if so, updating according to a turning condition formula corrected based on the slip rate; otherwise, updating according to a linear driving working condition formula based on slip rate correction; and obtaining the current pose estimation of the unmanned vehicle according to the speedometer update value. According to the method, information transmitted back by the accelerometer, the wheel speed sensor and the gyroscope in real time on the vehicle is fused through an algorithm, the wheel speed information is corrected, and the precision of vehicle pose estimation under the satellite denial condition can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned vehicle posture estimation, and provides a method, system and device for estimating the posture of a differential unmanned vehicle based on slip rate correction. Background Art

[0002] An unmanned vehicle's position and posture information primarily includes speed, position relative to the starting point, and posture. Obtaining accurate and reliable real-time position and posture information during unmanned vehicle operation can significantly improve control accuracy. Currently, integrated navigation systems, combining the Global Navigation Satellite System (GNSS) and the Inertial Navigation System (INS), are widely used in unmanned vehicles due to their high accuracy and low cost. However, in satellite-denied environments, such as mines and tunnels, the use of satellite navigation systems is limited, and the accuracy of GNSS / INS integrated navigation cannot be guaranteed. Therefore, additional sensors are needed to compensate for the reduced accuracy of integrated navigation in satellite-denied environments.

[0003] Currently, most inertial navigation systems (INS) on the market ignore the impact of slip rate when calculating vehicle mileage, resulting in large errors in vehicle pose estimation, seriously affecting the accuracy of autonomous driving for unmanned vehicles. Accelerometers, wheel speed sensors, and gyroscopes are widely used in the unmanned vehicle sector due to their low price, strong anti-interference capabilities, and high product maturity. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the related art. To this end, the present invention provides a method and system for estimating the pose of a differential unmanned vehicle based on slip rate correction, which corrects wheel speed information and effectively improves the accuracy of vehicle pose estimation in satellite denial situations.

[0005] The present invention provides a method for estimating the position and posture of a differential unmanned vehicle based on slip rate correction, comprising: S1: Based on the vehicle motion principle, simplify the kinematic model of the differential unmanned vehicle; S2: Install an acceleration sensor on the unmanned vehicle to obtain the left and right wheel accelerations; S3: Install a speed sensor on the unmanned vehicle to obtain the left and right wheel speeds; S4: Calculate the tire slip rate based on the left wheel acceleration, right wheel acceleration, left wheel speed, right wheel speed and the differential unmanned vehicle kinematic model; S5: Install a gyroscope in the middle of the unmanned vehicle and use it to obtain the vehicle's position angle; S6: Determine whether the difference between the left wheel acceleration and the right wheel acceleration is greater than a threshold. If the difference is greater than the threshold, update the odometer according to a turning condition formula based on slip ratio correction. Otherwise, update the odometer according to a straight-line driving condition formula based on slip ratio correction to obtain an updated value. S7: Based on the updated value of the odometer, the current position of the unmanned vehicle is estimated.

[0006] According to a slip rate correction-based differential unmanned vehicle posture estimation method provided by the present invention, all wheels on the left side are replaced by one wheel, all wheels on the right side are replaced by one wheel, and the vehicle body is replaced by a rigid body.

[0007] According to a method for estimating a differential unmanned vehicle's posture based on slip rate correction provided by the present invention, step S2 includes: An acceleration sensor is installed on the vehicle body next to the left wheel to obtain the left wheel acceleration; an acceleration sensor is installed on the vehicle body next to the right wheel to obtain the right wheel acceleration; Step S3 includes: A speed sensor is installed on the left wheel to obtain the left wheel speed; a speed sensor is installed on the right wheel to obtain the right wheel speed.

[0008] According to a differential unmanned vehicle posture estimation method based on slip rate correction provided by the present invention, step S4 includes: when the unmanned vehicle is in a driving state, the slip rate calculation formula of the left wheel is: in, When driving, the left wheel Slip rate at the moment; When driving, the left wheel Slip rate at the moment; For the revolver The wheel speed of the moment, For the revolver The wheel speed of the moment, For the revolver The acceleration of time, is the time interval, For time; The slip rate calculation formula of the right wheel is: in, When driving, the right wheel Slip rate at the moment; When driving, the right wheel Slip rate at the moment; For the right wheel The wheel speed of the moment, For the right wheel The wheel speed of the moment, For the right wheel The acceleration of time.

[0009] According to a method for estimating the position of a differential unmanned vehicle based on slip rate correction provided by the present invention, step S6 includes: threshold Determined according to the maximum driving speed of the unmanned vehicle chassis, the formula is: in, is the maximum speed of the unmanned vehicle chassis; When the difference between the left wheel acceleration and the right wheel acceleration is greater than the threshold, the slip-rate-corrected turning odometer update formula is as follows: in, For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the The position angle of the autonomous vehicle at the moment; For the The position angle of the autonomous vehicle at the moment; is the wheelbase, For The corrected displacement of the left wheel during the time period, For The corrected displacement of the right wheel during the time period; the unmanned vehicle's forward direction is direction positive direction, The positive direction is the right turn direction of the unmanned vehicle. Direction and The directions are perpendicular to each other, For time; When the difference between the left wheel acceleration and the right wheel acceleration is not greater than the threshold, the odometer update formula for straight-line driving based on slip rate correction is as follows: .

[0010] According to a method for estimating the position of a differential unmanned vehicle based on slip rate correction provided by the present invention, step S6 includes: when the unmanned vehicle is in a driving state, The calculation formula is: in, For The corrected displacement of the left wheel during the time period; When driving, the left wheel Slip rate at the moment; For the revolver Wheel speed at the moment; is the time interval, For time; The calculation formula is: in, For The corrected displacement of the right wheel during the time period; For the right wheel Wheel speed at the moment; When driving, the right wheel Slip rate at the moment; is the time interval.

[0011] According to a method for estimating the position of a differential unmanned vehicle based on slip rate correction provided by the present invention, step S6 includes: when the unmanned vehicle is in a braking state, The calculation formula is: in, For The corrected displacement of the right wheel during the time period; For the right wheel Wheel speed at the moment; When braking, the right wheel Slip rate at the moment; is the time interval; The calculation formula is: in, For The corrected displacement of the left wheel during the time period; For the revolver Wheel speed at the moment; When braking, the left wheel Slip rate at the moment; is the time interval.

[0012] The present invention also provides a differential unmanned vehicle posture estimation system based on slip rate correction, comprising: Motion parameter acquisition module: used to simplify the kinematic model of the differential unmanned vehicle based on the vehicle motion principle; install an acceleration sensor on the unmanned vehicle to obtain the left and right wheel accelerations; install a speed sensor on the unmanned vehicle to obtain the left and right wheel speeds; Slip ratio calculation module: used to calculate the tire slip ratio based on the left wheel acceleration, right wheel acceleration, left wheel speed, right wheel speed and differential unmanned vehicle kinematic model; Attitude acquisition module: used to install a gyroscope in the middle of the unmanned vehicle and use the gyroscope to obtain the vehicle's posture angle; Odometer calculation module: This module determines whether the difference between the left and right wheel accelerations is greater than a threshold. If so, the odometer is updated using a slip-rate-corrected formula for cornering conditions. Otherwise, the odometer is updated using a slip-rate-corrected formula for straight-line driving conditions to obtain an updated value. Position estimation module: used to estimate the current position of the unmanned vehicle based on the updated value.

[0013] The present invention also provides an electronic device comprising a processor, a communication interface, a memory and a communication bus. When the processor executes the program, the steps of any of the above-mentioned methods for estimating the position and posture of a differential unmanned vehicle based on slip rate correction are implemented.

[0014] The above one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects: The present invention provides a method, system, and device for estimating the posture of a differential unmanned vehicle based on slip rate correction. By using an algorithm, the system fuses the information transmitted in real time by the vehicle's accelerometer, wheel speed sensor, and gyroscope, calculates the real-time slip rate, and corrects the wheel speed information. This method can effectively improve the accuracy of vehicle posture estimation in satellite denial situations.

[0015] The sensors required for the slip-rate-corrected six-wheel differential unmanned vehicle pose estimation method proposed in this patent application primarily include accelerometers, wheel speed sensors, and gyroscopes. These sensors are inexpensive, have strong anti-interference properties, and are economical. Slip is a common phenomenon during vehicle operation, especially on roads with low ground adhesion, where significant slip can occur. Slip can cause the vehicle's actual speed to deviate from its theoretical speed, affecting the accuracy of the odometer in the inertial navigation system (INS) and leading to large errors in real-time pose estimation. The slip rate directly affects the positioning accuracy of the INS, a factor particularly pronounced in satellite-denied environments. The slip-rate-corrected six-wheel differential unmanned vehicle pose estimation method proposed in this patent application considers the impact of the real-time slip rate when calculating the vehicle's real-time pose, effectively compensating for the reduced accuracy of integrated navigation in satellite-denied environments.

[0016] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 The present invention provides a flow chart of a method for estimating the position and posture of a differential unmanned vehicle based on slip rate correction.

[0019] Figure 2 This is a simplified result diagram of the kinematic model of a six-wheel differential unmanned vehicle.

[0020] Figure 3 This is a diagram of the layout of the perception sensors on the vehicle.

[0021] Figure 4 This is a schematic diagram of the posture angles of a six-wheel differential unmanned vehicle.

[0022] Figure 5 This is a structural block diagram of a differential unmanned vehicle posture estimation system based on slip rate correction provided by the present invention.

[0023] Figure 6 It is a structural schematic diagram of the electronic device provided by the present invention.

[0024] Reference numerals: 1. Left wheel speed sensor; 2. Right wheel speed sensor; 3. Left acceleration sensor; 4. Right acceleration sensor; 5. Gyroscope; 101. Motion parameter acquisition module; 102. Slip rate calculation module; 103. Posture acquisition module; 104. Odometer calculation module; 105. Posture estimation module; 810. Processor; 820. Communication interface; 830. Memory; 840. Communication bus. DETAILED DESCRIPTION

[0025] To make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below. Obviously, the embodiments described are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0026] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0027] The following combination Figures 1 to 6 The present invention is described.

[0028] Example like Figure 1 As shown, Figure 1 This is a flow chart of a method for estimating the position and posture of a differential unmanned vehicle based on slip rate correction provided by the present invention. The method includes the following steps: S1: Based on the vehicle motion principle, simplify the kinematic model of the differential unmanned vehicle; S2: Install an acceleration sensor on the unmanned vehicle to obtain the left and right wheel accelerations; S3: Install a speed sensor on the unmanned vehicle to obtain the left and right wheel speeds; S4: Calculate the tire slip rate based on the left wheel acceleration, right wheel acceleration, left wheel speed, right wheel speed and the differential unmanned vehicle kinematic model; S5: Install a gyroscope 5 in the middle of the unmanned vehicle and use the gyroscope 5 to obtain the vehicle's posture angle; S6: Determine whether the difference between the left wheel acceleration and the right wheel acceleration is greater than a threshold. If the difference is greater than the threshold, update the odometer according to a turning condition formula based on slip ratio correction. Otherwise, update the odometer according to a straight-line driving condition formula based on slip ratio correction to obtain an updated value. S7: Based on the updated value, an estimate of the current position of the unmanned vehicle is obtained.

[0029] Specifically, such as Figure 2 The simplified kinematic model of the differential unmanned vehicle is shown as follows: Replace all the wheels on the left side with one wheel, replace all the wheels on the right side with one wheel, and replace the car body with a rigid body.

[0030] Specifically, such as Figure 3 As shown, step S2 includes: A left acceleration sensor 3 is installed on the vehicle body next to the left wheel to obtain the left wheel acceleration; a right acceleration sensor 4 is installed on the vehicle body next to the right wheel to obtain the right wheel acceleration; Specifically, step S3 includes: A left wheel speed sensor 1 is installed on the left wheel to obtain the left wheel speed; a right wheel speed sensor 2 is installed on the right wheel to obtain the right wheel speed.

[0031] Specifically, step S4 includes: when the unmanned vehicle is in the driving state, the slip rate calculation formula of the left wheel is: in, When driving, the left wheel Slip rate at the moment; When driving, the left wheel Slip rate at the moment; For the revolver The wheel speed of the moment, For the revolver The wheel speed of the moment, For the revolver The acceleration of time, is the time interval; The slip rate calculation formula of the right wheel is: in, When driving, the right wheel Slip rate at the moment; When driving, the right wheel Slip rate at the moment; For the right wheel The wheel speed of the moment, For the right wheel The wheel speed of the moment, For the right wheel The acceleration of time.

[0032] When the unmanned vehicle is in the braking state, the slip rate calculation formula of the left wheel is: in, When braking, the left wheel Slip rate at the moment; When braking, the left wheel Slip rate at the moment; For the revolver The wheel speed of the moment, For the revolver The wheel speed of the moment, For the revolver The acceleration of time, is the time interval; The slip rate calculation formula of the right wheel is: in, When braking, the right wheel Slip rate at the moment; When braking, the right wheel Slip rate at the moment; For the right wheel The wheel speed of the moment, For the right wheel The wheel speed of the moment, For the right wheel The acceleration of time.

[0033] like Figure 4 As shown, the unmanned vehicle is moving in the direction direction positive direction, The positive direction is the right turn direction of the unmanned vehicle. Direction and The directions are perpendicular to each other. In the embodiment of the present invention, after the vehicle starts from a stationary state, As an example, calculate the value of the pose estimation. The moment is stationary, the left wheel is Slip rate at time , right wheel in Slip rate at time , the revolver is Acceleration of time , right wheel in Acceleration of time , the revolver is Wheel speed at all times , right wheel in Wheel speed at all times . Revolver in Wheel speed at all times ; Right wheel Wheel speed at all times According to the measurement of gyroscope 5, The posture angle of the autonomous vehicle at the moment In the The posture angle of the autonomous vehicle at the moment The maximum speed of the unmanned vehicle chassis Wheelbase The six-wheel differential unmanned vehicle is driven by dual motors and rear wheels. The left motor drives the three wheels on the left through a chain drive, and the right motor drives the three wheels on the right through a chain drive.

[0034] From the conditions of the example, we can see that the six-wheel differential unmanned vehicle in the example is in the driving state, and the slip rate of the left wheel is obtained by the following formula: The slip ratio of the right wheel is given by the following formula: Specifically, step S6 includes: threshold Determined according to the maximum driving speed of the unmanned vehicle chassis, the formula is: in, is the maximum speed of the unmanned vehicle chassis; The update formula of the turning odometer based on slip rate correction is as follows: in, For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the The position angle of the autonomous vehicle at the moment; For the The position angle of the autonomous vehicle at the moment; is the wheelbase, For The corrected displacement of the left wheel during the time period, For The corrected displacement of the right wheel during the time period; The update formula of the straight-line driving odometer based on slip rate correction is as follows: in, For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the The position angle of the autonomous vehicle at the moment; For The corrected displacement of the left wheel during the time period; For Corrected displacement of the right wheel during the time period.

[0035] When the autonomous vehicle is in driving state, exist Corrected displacement of the left wheel within the time period Calculated by the following formula: in, For The corrected displacement of the left wheel during the time period; When driving, the left wheel Slip rate at the moment; For the revolver Wheel speed at the moment; is the time interval; exist Corrected displacement of the right wheel within the time period Calculated by the following formula: in, For The corrected displacement of the right wheel during the time period; For the right wheel Wheel speed at the moment; When driving, the right wheel Slip rate at the moment; is the time interval.

[0036] When the autonomous vehicle is in braking state, exist Corrected displacement of the right wheel within the time period Calculated by the following formula: in, For The corrected displacement of the right wheel during the time period; For the right wheel Wheel speed at the moment; When braking, the right wheel Slip rate at the moment; is the time interval; exist Corrected displacement of the left wheel within the time period Calculated by the following formula: in, For The corrected displacement of the left wheel during the time period; For the revolver Wheel speed at the moment; When braking, the left wheel Slip rate at the moment; is the time interval.

[0037] According to the conditions in the example, the maximum speed of the unmanned vehicle chassis is , threshold Determined by the following formula: because ,Therefore, it is necessary to update the odometer according to the straight-line driving condition formula based on the slip ratio correction.

[0038] In the embodiment of the present invention, the unmanned vehicle is in a driving state, therefore, exist Corrected displacement of the left wheel within the time period for: The six-wheel differential unmanned vehicle is in driving state. Corrected displacement of the right wheel within the time period for: The update formula of the straight-line driving odometer based on slip rate correction is as follows: In summary, according to the updated value of the odometer, the current position of the unmanned vehicle is estimated. Time compared to moment, in The displacement in the direction is 0.343m. The displacement in the direction is 0.06m.

[0039] The present invention provides a method, system, and device for estimating the posture of a differential unmanned vehicle based on slip rate correction. By using an algorithm, the system fuses the information transmitted in real time by the vehicle's accelerometer, wheel speed sensor, and gyroscope, calculates the real-time slip rate, and corrects the wheel speed information. This method can effectively improve the accuracy of vehicle posture estimation in satellite denial situations.

[0040] like Figure 5 As shown, the present invention provides a differential unmanned vehicle posture estimation device based on slip rate correction, comprising the following modules: Motion parameter acquisition module 101: used to simplify the kinematic model of the differential unmanned vehicle based on the vehicle motion principle; install an acceleration sensor on the unmanned vehicle to obtain the left wheel acceleration and the right wheel acceleration; install a speed sensor on the unmanned vehicle to obtain the left wheel speed and the right wheel speed; Slip ratio calculation module 102: used to calculate tire slip ratio based on left wheel acceleration, right wheel acceleration, left wheel speed, right wheel speed and differential unmanned vehicle kinematic model; Attitude acquisition module 103: a gyroscope is installed in the middle of the unmanned vehicle and uses the gyroscope to obtain the vehicle's posture angle; Odometer calculation module 104: used to determine whether the difference between the left wheel acceleration and the right wheel acceleration is greater than a threshold. If the difference is greater than the threshold, the odometer is updated according to a turning condition formula based on slip ratio correction. Otherwise, the odometer is updated according to a straight-line driving condition formula based on slip ratio correction to obtain an updated value. The pose estimation module 105 is used to estimate the current pose of the unmanned vehicle based on the updated value of the odometer.

[0041] Figure 6 An example of a physical structure diagram of an electronic device is shown below. Figure 6 As shown, the electronic device may include: a processor 810, a communication interface 820, a memory 830, and a communication bus 840, wherein the processor 810, the communication interface 820, and the memory 830 communicate with each other via the communication bus 840. The processor 810 may call the logic instructions in the memory 830 to execute a method for estimating the position and posture of a differential unmanned vehicle based on slip rate correction, the method comprising: S1: Based on the vehicle motion principle, simplify the kinematic model of the differential unmanned vehicle; S2: Get the left wheel acceleration and the right wheel acceleration; S3: Get the left wheel speed and the right wheel speed; S4: Calculate the tire slip rate based on the left wheel acceleration, right wheel acceleration, left wheel speed, right wheel speed and the differential unmanned vehicle kinematic model; S5: A gyroscope is installed in the middle of the unmanned vehicle, which is used to obtain the vehicle's posture angle; S6: Determine whether the difference between the left wheel acceleration and the right wheel acceleration is greater than a threshold. If the difference is greater than the threshold, update the odometer according to a turning condition formula based on slip ratio correction; otherwise, update the odometer according to a straight-line driving condition formula based on slip ratio correction. S7: Based on the updated value of the odometer, the current position of the unmanned vehicle is estimated.

[0042] Furthermore, the logic instructions in the aforementioned memory 830 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product, stored in a storage medium, includes instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, mobile hard drives, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical disks.

[0043] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0044] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

[0046] It should be noted that the embodiments of the present disclosure can be implemented by hardware, software, or a combination of software and hardware. The hardware portion can be implemented using dedicated logic; the software portion can be stored in a memory and executed by an appropriate instruction execution system such as a microprocessor or dedicated hardware. Those skilled in the art will understand that the above-mentioned devices and methods can be implemented using computer-executable instructions and / or contained in processor control code, for example, such code is provided on a programmable memory or a data carrier such as an optical or electronic signal carrier.

[0047] In addition, although the operations of the method of the present disclosure are described in a particular order in the accompanying drawings, this does not require or imply that these operations must be performed in this particular order, or that all the operations shown must be performed to achieve the desired result. On the contrary, the steps depicted in the flow chart can change the order of execution. Additionally or alternatively, certain steps can be omitted, multiple steps can be combined into one step, and / or one step can be decomposed into multiple steps. It should also be noted that the features and functions of two or more devices according to the present disclosure can be embodied in one device. Conversely, the features and functions of a device described above can be further divided into being embodied by multiple devices.

[0048] Although the present disclosure has been described with reference to several specific embodiments, it should be understood that the present disclosure is not limited to the specific embodiments disclosed. The present disclosure is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A method for position estimation of a differential unmanned vehicle based on slip rate correction, characterized in that: The following steps are involved: S1: Based on the vehicle motion principle, simplify the kinematic model of the differential unmanned vehicle; S2: Install an acceleration sensor on the unmanned vehicle to obtain the left and right wheel accelerations; S3: Install a speed sensor on the unmanned vehicle to obtain the left and right wheel speeds; S4: Calculate the tire slip rate based on the left wheel acceleration, right wheel acceleration, left wheel speed, right wheel speed and the differential unmanned vehicle kinematic model; S5: Install a gyroscope in the middle of the unmanned vehicle and use it to obtain the vehicle's position angle; S6: Determine whether the difference between the left wheel acceleration and the right wheel acceleration is greater than a threshold. If the difference is greater than the threshold, update the odometer according to a turning condition formula based on slip ratio correction. Otherwise, update the odometer according to a straight-line driving condition formula based on slip ratio correction to obtain an updated value. S7: Based on the updated value, an estimate of the current position of the unmanned vehicle is obtained.

2. The method for position estimation of a differential unmanned vehicle based on slip rate correction according to claim 1, characterized in that: The kinematic model of the differential unmanned vehicle is: Replace all the wheels on the left side with one wheel, replace all the wheels on the right side with one wheel, and replace the car body with a rigid body.

3. The method for position estimation of a differential unmanned vehicle based on slip rate correction according to claim 1, characterized in that: Step S2 includes: An acceleration sensor is installed on the vehicle body next to the left wheel to obtain the left wheel acceleration; an acceleration sensor is installed on the vehicle body next to the right wheel to obtain the right wheel acceleration; Step S3 includes: A speed sensor is installed on the left wheel to obtain the left wheel speed; a speed sensor is installed on the right wheel to obtain the right wheel speed.

4. The method for position estimation of a differential unmanned vehicle based on slip rate correction according to claim 1, characterized in that: Step S4 includes: when the unmanned vehicle is in the driving state, the slip rate of the left wheel is calculated as follows: in, When driving, the left wheel Slip rate at the moment; When driving, the left wheel Slip rate at the moment; For the revolver The wheel speed of the moment, For the revolver The wheel speed of the moment, For the revolver The acceleration of time, is the time interval, For time; The slip rate calculation formula of the right wheel is: in, When driving, the right wheel Slip rate at the moment; When driving, the right wheel Slip rate at the moment; For the right wheel The wheel speed of the moment, For the right wheel The wheel speed of the moment, For the right wheel The acceleration of time.

5. The method for position estimation of a differential unmanned vehicle based on slip rate correction according to claim 1, characterized in that: Step S4 includes: when the unmanned vehicle is in a braking state, the slip rate of the left wheel is calculated as follows: in, When braking, the left wheel Slip rate at the moment; When braking, the left wheel Slip rate at the moment; For the revolver The wheel speed of the moment, For the revolver The wheel speed of the moment, For the revolver The acceleration of time, is the time interval, For time; The slip rate calculation formula of the right wheel is: in, When braking, the right wheel Slip rate at the moment; When braking, the right wheel Slip rate at the moment; For the right wheel The wheel speed of the moment, For the right wheel The wheel speed of the moment, For the right wheel The acceleration of time.

6. The method for position estimation of a differential unmanned vehicle based on slip rate correction according to claim 1, characterized in that: Step S6 includes: threshold Determined according to the maximum driving speed of the unmanned vehicle chassis, the formula is: in, is the maximum speed of the unmanned vehicle chassis; When the difference between the left wheel acceleration and the right wheel acceleration is greater than the threshold, the slip-rate-corrected turning odometer update formula is as follows: in, For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the Unmanned vehicles at all times displacement in direction; For the The position angle of the autonomous vehicle at the moment; For the The position angle of the autonomous vehicle at the moment; is the wheelbase, For The corrected displacement of the left wheel during the time period, For The corrected displacement of the right wheel during the time period; the unmanned vehicle's forward direction is direction positive direction, The positive direction is the right turn direction of the unmanned vehicle. Direction and The directions are perpendicular to each other, For time; When the difference between the left wheel acceleration and the right wheel acceleration is not greater than the threshold, the odometer update formula for straight-line driving based on slip rate correction is as follows: 。 7. The method for position estimation of a differential unmanned vehicle based on slip rate correction according to claim 6, characterized in that: Step S6 includes: when the unmanned vehicle is in the driving state, The calculation formula is: in, When driving, the left wheel Slip rate at the moment; For the revolver Wheel speed at the moment; is the time interval; The calculation formula is: in, For the right wheel Wheel speed at the moment; When driving, the right wheel Slip rate at time;.

8. The method for position estimation of a differential unmanned vehicle based on slip rate correction according to claim 6, characterized in that: Step S6 includes: when the unmanned vehicle is in a braking state, The calculation formula is: in, For the right wheel Wheel speed at the moment; When braking, the right wheel Slip rate at the moment; is the time interval; The calculation formula is: in, For the revolver Wheel speed at all times.

9. A system for estimating the position and attitude of a differential-speed autonomous vehicle based on slip rate correction, for executing the method for estimating the position and attitude of a differential-speed autonomous vehicle based on slip rate correction as claimed in any one of claims 1 to 7, characterized in that: include: Motion parameter acquisition module: used to simplify the kinematic model of the differential unmanned vehicle based on the vehicle motion principle; Install an acceleration sensor on the unmanned vehicle to obtain the left and right wheel accelerations; Install speed sensors on the unmanned vehicle to obtain the left and right wheel speeds; Slip ratio calculation module: used to calculate the tire slip ratio based on the left wheel acceleration, right wheel acceleration, left wheel speed, right wheel speed and differential unmanned vehicle kinematic model; Attitude acquisition module: used to install a gyroscope in the middle of the unmanned vehicle and use the gyroscope to obtain the vehicle's posture angle; Odometer calculation module: used to determine whether the difference between the left and right wheel accelerations is greater than a threshold. If the difference is greater than the threshold, the odometer is updated according to the turning condition formula based on the slip rate correction. Otherwise, the odometer is updated according to the straight-line driving condition formula based on the slip ratio correction to obtain an updated value; Position estimation module: used to estimate the current position of the unmanned vehicle based on the updated value.

10. An electronic device comprising a processor, a communication interface, a memory and a communication bus, characterized in that: When the processor executes the computer program, the steps of the method for estimating the position posture of a differential unmanned vehicle based on slip rate correction as described in any one of claims 1 to 7 are implemented.

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