Differential mobile robot in-situ yaw speed planning method, system and device and storage medium

Abstract

The invention discloses an in-situ yaw speed planning method, system and device for a differential mobile robot and a storage medium. The method comprises the steps that 1, in-situ yaw information is acquired; 2, discretizing the path into a series of planning points, and traversing each planning point to establish the maximum angular velocity constraint of each planning point; 3, acquiring the angular velocity of the starting point of the first planning point; 4, acquiring the angular velocity of the corresponding planning point under the acceleration look-ahead limitation; step 5, acquiring the last planning point, namely an end point; step 6, acquiring the angular velocity of the corresponding planning point under the deceleration rear-view limitation; step 7, calculating the yaw time interval between the two adjacent planning points; step 8, judging whether the steering direction between the adjacent planning points is anticlockwise, if so, taking the original value of the planned angular velocity; otherwise, taking an opposite value; and step 9, outputting speed control information, namely speed instructions of left and right wheels. The stability and controllability of the in-situ yaw process are improved, and it is guaranteed that the mobile robot accurately tracks on any continuous path.

Description

Technical Field

[0001] The present invention relates to the technical field of differential mobile robot navigation, and in particular to a method, system, device and storage medium for planning the in-situ yaw speed of a differential mobile robot. Background Art

[0002] Currently, most speed planning methods for mobile robots adopt multi-segment speed planning methods, which adjust the speed by obtaining the acceleration and deceleration points in the corresponding intervals during the movement process. Such methods have a non-smooth speed transition, are difficult to ensure the planning accuracy and have poor controllability, as described in patents CN 107102641A and CN 108681322A; for the problem of discontinuous path curvature, currently, most methods use curve fitting and non-linear programming to optimize and smooth the path. Such methods are computationally complex, consume a large amount of computing power resources, and there is a loss of accuracy during the fitting process, resulting in a large deviation between the fitted path and the original path, and the traveling space is not completely controllable, which is not suitable for situations where the traveling space is limited or a predetermined path needs to be strictly executed, as described in patent CN 115793664A. Especially for the differential mobile robot navigation technology that needs to adjust the yaw angle at a specific position, for example, when a factory handling mobile robot reaches a designated work station, it needs to adjust its attitude to a specific yaw angle to facilitate the precise docking and transfer of goods; another example is that when a mobile robot enters the station for charging, it needs to adjust the yaw angle for precise connection to the charging pile interface; such differential mobile robots need to limit the in-situ yaw speed when reaching the designated work station to facilitate interaction with devices such as vision and robotic arms. However, the existing speed planning methods have discontinuous first or second derivatives of their paths, resulting in the problem that speed planning cannot be carried out in a timely manner; that is, a new method for planning the in-situ yaw speed of a differential mobile robot needs to be designed to adjust the yaw angle at the discontinuous point and perform attitude trajectory planning. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for planning the in-situ yaw speed of a differential mobile robot, aiming to solve the technical problem of the drawbacks existing in traditional in-situ yaw speed planning, that is, to solve the problem that speed planning cannot be carried out at the discontinuous points of the first or second derivative of the path (for example, sharp inflection points and sharp turns on the path), so as to solve the problem of in-situ yaw speed planning of mobile robots.

[0004] To solve the above problems, the present invention provides a method for planning the in-situ yaw speed of a differential mobile robot, and its corresponding technical solutions include:

[0005] Step 1, obtain in-situ yaw information;

[0006] Step 2, discretize the path into a series of dense planning points, denoted as P1,...,P i ,...,P n, for \(1 < i < n - 1\), traverse each planned point to establish the maximum angular velocity constraint of each planned point, that is, the first maximum allowable angular velocity constraint;

[0007] Step 3: Obtain the angular velocity \(\omega_1\) of the first planned point, i.e., the starting point;

[0008] Step 4: Obtain the angular velocity of the planned point \(P\) i under the acceleration look-ahead limit to obtain the angular velocity of each planned point under the acceleration look-ahead constraint, and compare it with the first maximum allowable angular velocity constraint, and take the minimum value as the second maximum allowable angular velocity constraint. The expression of the angular velocity under the corresponding acceleration look-ahead constraint is:

[0009]

[0010] where,

[0011] \(\omega\) i-1 is the angular velocity of the planned point \(P\) i-1 ;

[0012] is the maximum angular acceleration of the mobile robot;

[0013] \(\Delta s\) is the modulus of the angular displacement between the planned point \(P\) i-1 and \(P\) i ;

[0014] Step 5: Obtain the last planned point, i.e., the end point, and assign the end point angular velocity to 0;

[0015] Step 6: Obtain the velocity of the planned point \(P\) i under the deceleration look-behind limit to obtain the deceleration look-behind constraint of each planned point and compare it with the second maximum allowable angular velocity constraint, and take the minimum value of the two as the final maximum allowable angular velocity constraint. The expression of the angular velocity under the corresponding deceleration look-behind constraint is:

[0016]

[0017] where,

[0018] \(\omega\) i+1 is the angular velocity of the planned point \(P\) i+1 ;

[0019] is the maximum angular deceleration of the mobile robot;

[0020] \(\Delta s\) is the modulus of the angular displacement between the planned point \(P\) i and \(P\) i+1 ;

[0021] Step 7: Calculate the yaw time interval between two adjacent planned points;

[0022] Step 8, determine the planned point P i-1 to P i Whether the turning direction in between is counterclockwise. If so, the planned angular velocity takes the original value of the calculation result corresponding to Step 7; otherwise, take the opposite value;

[0023] Step 9, output the speed control information, that is, the speed commands of the left and right wheels.

[0024] Furthermore, the aforementioned in-place yaw information includes the initial yaw angle θ start and the target yaw angle θ target , the angular displacement Δθ and the turning direction.

[0025] Furthermore, traverse each planned point to establish a maximum angular velocity constraint, and the corresponding expression is:

[0026] ω i ← min{||ω max ||, ||ω limit ||},

[0027] wherein,

[0028] ||ω max || is the modulus of the maximum angular velocity that can be achieved to satisfy the kinematic constraints of the robot body;

[0029] ||ω limit || is the modulus of the maximum angular velocity speed limit obtained artificially;

[0030] ω i is the maximum allowable speed at the planned point P i , and there is

[0031] Furthermore, the angular velocity ω1 at the starting point, the corresponding expression is:

[0032] ω1 = ||ω current ||,

[0033] wherein, ||ω current || is the modulus of the current angular velocity of the mobile robot.

[0034] Furthermore, assuming that the angular acceleration a ω is constant within the interval between two adjacent planned points, then the expression for the yaw time interval corresponding to the adjacent planned points P i-1 to P i is:

[0035]

[0036] wherein,

[0037] Δs is the planned point Pi-1 and P i The magnitude of the angular displacement therebetween.

[0038] Originating from the same inventive concept, the present invention also designs a differential mobile robot in-situ yaw speed planning system, which includes:

[0039] An information acquisition unit, and the aforementioned information acquisition unit is used to acquire in-situ yaw information, and the aforementioned in-situ yaw information includes an initial yaw angle θ start and a target yaw angle θ target , an angular displacement Δθ and a steering direction;

[0040] An information preprocessing unit, and the aforementioned information preprocessing unit is used to discretize a path into a series of planned points, and traverse each planned point to establish a maximum angular velocity constraint for each planned point, namely a first maximum allowable angular velocity constraint;

[0041] A first angular velocity constraint unit, and the aforementioned first angular velocity constraint unit is used to acquire the angular velocity ω1 of the first planned point, i.e., the starting point; and acquire the angular velocity of the planned point P i under the acceleration look-ahead limit to obtain the angular velocity under the acceleration look-ahead constraint of each planned point, and compare it with the first maximum allowable angular velocity constraint, and take the minimum value thereof as the second maximum allowable angular velocity constraint;

[0042] A second angular velocity constraint unit, and the aforementioned second angular velocity constraint unit is used to acquire the last planned point, i.e., the end point, and assign the end point angular velocity to 0;

[0043] Meanwhile, acquire the velocity of the planned point P i under the deceleration look-behind limit to obtain the deceleration look-behind constraint of each planned point and compare it with the second maximum allowable angular velocity constraint, and take the minimum value of the two as the final maximum allowable angular velocity constraint;

[0044] A control unit, and this control unit is used to calculate the yaw time interval between two adjacent planned points and judge whether the steering direction between the planned point P i-1 and P i is counterclockwise. If so, the planned angular velocity takes the original value of the calculation result corresponding to the yaw time interval; otherwise, take the opposite value; meanwhile, output speed control information, i.e., the speed commands of the left and right wheels.

[0045] Furthermore, traverse each planned point to establish a maximum angular velocity constraint, and the corresponding expression is:

[0046] ω i ←min{||ω max ||,||ω limit ||},

[0047] wherein,

[0048] ||ω max || is the magnitude of the maximum angular velocity that can be achieved to satisfy the kinematic constraints of the robot body;

[0049] ||ω limit || is the magnitude of the maximum angular velocity limit obtained artificially;

[0050] ω i is the maximum allowable angular velocity at the planned point P i and there is

[0051] Furthermore, the angular velocity ω1 at the starting point has the corresponding expression:

[0052] ω1 = ||ω current ||

[0053] where ||ω current || is the magnitude of the current angular velocity of the mobile robot;

[0054] Meanwhile, it is assumed that the angular acceleration a ω is constant within the interval between two adjacent planned points, then the expression for the yaw time interval corresponding to the adjacent planned points P i-1 to P i is:

[0055]

[0056] where

[0057] Δs is the magnitude of the angular displacement between the planned points P i-1 and P i ;

[0058] Derived from the same inventive concept, the present invention also designs a differential mobile robot device, which is loaded with a calculation and control device, and is characterized in that the calculation and control device includes: a memory and a processor, the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to execute the differential mobile robot in-situ yaw speed planning method described above.

[0059] Derived from the same inventive concept, the present invention also designs a computer-readable storage medium, which is characterized in that the computer-readable storage medium stores computer instructions, and the computer instructions are used to cause a computer to execute the differential mobile robot in-situ yaw speed planning method described above.

[0060] Implementing the embodiments of the present invention will have the following beneficial effects:

[0061] The present invention uses the motion constraints and speed limit information of the differential mobile robot body to plan the in-place yaw speed, improve the smoothness and controllability of the in-place yaw process, ensure that the mobile robot accurately follows the track on any continuous path, and provides a stable and highly controllable in-place yaw speed planning scheme. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0063] Among them:

[0064] Figure 1 is the overall step flowchart of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0065] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0066] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0067] In addition, the descriptions involving "first", "second", etc. in the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0068] Such as Figure 1 , the in-place yaw speed planning method for a differential mobile robot proposed by the present invention includes the following 9 steps in total:

[0069] Step 1: Obtain the in-place yaw information, where the in-place yaw information includes the initial yaw angle θ start and the target yaw angle θ target , the angular displacement Δθ, and the turning direction. Among them, the initial yaw angle θ start is obtained as the current yaw angle of the robot; according to different task requirements, the acquisition of the target yaw angle θ target is divided into two cases: ① It is obtained as a yaw angle specified by a human (such as a fixed-point turning task); ② It is obtained as the tangent direction of the starting point of the path segment to be entered (such as a path tracking task).

[0070] Step 2: Discretize the planned points based on the two yaw angles of the in-place yaw information, that is, discretize the path into a series of dense planned points (P1,..., P i ,..., P n ), 1 < i < n - 1. Traverse each planned point to establish the maximum angular velocity constraint of each planned point, that is, the first maximum allowable angular velocity constraint; combine the geometric characteristics of the path with the dynamic constraints of the robot to ensure the safety and smoothness of the movement; traverse each planned point to establish the maximum angular velocity constraint, and the corresponding expression is:

[0071] ω i ←min{||ω max ||,||ω limit ||},

[0072] where

[0073] ||ω max || is the modulus of the maximum angular velocity that can be achieved to satisfy the kinematic constraints of the robot body;

[0074] ||ω limit || is the modulus of the maximum angular velocity speed limit obtained artificially;

[0075] ω i is the maximum allowable angular velocity at the planned point P i , and there is

[0076] The number of planned points is obtained according to different discretization precisions.

[0077] The design key points of this step are as follows: First, due to the performance limitations of the robot, there will be a maximum angular velocity constraint that can be reached; second, considering the working conditions, it is necessary to artificially limit the maximum angular velocity; finally, take the smaller constraint value of the two as the upper bound of the angular velocity, that is, the first maximum allowable angular velocity constraint, that is, the first maximum allowable angular velocity constraint of each planned point of the current in-place yaw trajectory.

[0078] Step 3: Obtain the angular velocity ω1 of the first planned point, that is, the starting point, and the corresponding expression is:

[0079] ω1 = ||ω current ||,

[0080] where ||ω current || is the magnitude of the current angular velocity read in the mobile robot body. For a complete origin yaw trajectory, generally the speeds at the starting point and the ending point are both 0, but this also applies to the case where the starting angular velocity is non - zero.

[0081] Step 4: Obtain the planned point P under the angular acceleration look - ahead limit i of the angular velocity to obtain the angular velocity under the acceleration look - ahead constraint for each planned point, and compare it with the first maximum allowable angular velocity constraint, taking the minimum of them as the second maximum allowable angular velocity constraint. The expression of the angular velocity under the corresponding acceleration look - ahead constraint is:

[0082]

[0083] where

[0084] ω i-1 is the angular velocity of the planned point P i-1 ;

[0085] is the maximum angular acceleration of the mobile robot;

[0086] Δs is the magnitude of the angular displacement between the planned point P i-1 and P i i.e., the angular offset between adjacent planned points, which is related to the discretization accuracy of the planned points.

[0087] The key point of the design of this step is: First, according to the velocity - time formula, ω i = ω i-1 + a ω Δt, that is, the angular velocity at the next moment is equal to the angular velocity at the previous moment plus the velocity increment generated by the acceleration time; since the acceleration time is not easy to estimate, but the motion angle Δs is measurable, so Substituting the above formula gives the velocity - displacement formula, Second, this step is to obtain the maximum / minimum angular velocity that the next planned point can reach based on the angular velocity of the previous planned point under the maximum / minimum angular acceleration, that is, starting from the initial angular velocity, calculate the reachable velocity range of the next planned point under the angular acceleration constraint in turn. Also, in the case of acceleration, that is, the angular acceleration is greater than or equal to 0 and less than or equal to the maximum angular acceleration. Therefore, the planned point P under the aforementioned angular acceleration look - ahead limit can be obtained iThe angular velocity formula; that is, considering the limitations of the robot's body performance, starting from the initial planning point under the limitation of the maximum angular acceleration, according to the initial angular velocity, the maximum achievable angular velocity of the next planning point is calculated in sequence, that is, according to the maximum angular acceleration, the maximum angular velocity when performing in-place yaw movement to the next planning point is calculated. At this time, the acceleration look-ahead constraint for each planning point is iteratively calculated based on the angular velocity and maximum acceleration of the initial planning point. Secondly, the acceleration look-ahead constraint obtained for each planning point is compared with the first maximum allowable angular velocity constraint, and the minimum value is taken as the second maximum allowable angular velocity constraint, that is, the second maximum allowable angular velocity constraint.

[0088] Step 5: Obtain the last planning point, that is, the end point, and assign the end point speed to 0;

[0089] Step 6: Obtain the planning point P under the deceleration look-behind limit i of the angular velocity to obtain the deceleration look-behind constraint for each planning point and compare it with the second maximum allowable angular velocity constraint, and take the minimum value of the two as the final maximum allowable angular velocity constraint. The angular velocity expression under the corresponding deceleration look-behind constraint is:

[0090]

[0091] where

[0092] ω i+1 is the angular velocity of the planning point P i+1 ;

[0093] is the maximum angular deceleration of the mobile robot;

[0094] Δs is the modulus of the angular displacement between the planning point P i and P i+1 .

[0095] The key points of the design of Steps 5 and 6 are: after the calculation in Step 4, the speed of the planning end point is the second maximum allowable angular velocity constraint; secondly, in Step 5, the end point speed is obtained as 0; then, starting from the planning end point and traversing towards the planning start point, according to the maximum angular deceleration, the deceleration look-behind limit of each planning point is calculated in sequence; finally, the deceleration look-behind constraint obtained for each planning point is compared with the second maximum allowable angular velocity constraint, and the minimum value is taken as the final maximum allowable angular velocity constraint.

[0096] Step 7: Calculate the yaw time interval between two adjacent planning points. Assuming that the angular acceleration a ω is constant within the interval between two adjacent planning points, then the expression for the yaw time interval corresponding to the adjacent planning points P i-1 to P i is:

[0097]

[0098] in,

[0099] Δs is the planning point P i-1 and P i The modulus of the angular displacement between them.

[0100] Step 8: Determine the planning point P i-1 to P i Is the steering direction counterclockwise? If so, the planned speed is the original value; otherwise, the reverse value is used. By default, the car is in the counterclockwise direction, and different steering directions determine the positive and negative values of the angular velocity output to the robot.

[0101] Step 9: Output speed control information, i.e., speed instructions for the left and right wheels.

[0102] Based on the same inventive concept, the present invention also designs an in-situ yaw velocity planning system for a differential mobile robot, which includes:

[0103] The information acquisition unit is used to obtain the in-situ yaw information, and the in-situ yaw information includes the initial yaw angle θ start Yaw angle θ with the target target , angular displacement Δθ and steering direction;

[0104] An information preprocessing unit, the information preprocessing unit being used to discretize the path into a series of planning points, and traverse each planning point to establish a maximum angular velocity constraint for each planning point, namely, a first maximum allowable angular velocity constraint;

[0105] The first angular velocity constraint unit is used to obtain the angular velocity ω1 of the first planning point, i.e., the starting point; and obtain the planning point P under the acceleration look-ahead constraint. i The angular velocity of each planning point is obtained under the acceleration look-ahead constraint, and the angular velocity is compared with the first maximum allowable angular velocity constraint, and the minimum value is taken as the second maximum allowable angular velocity constraint;

[0106] A second angular velocity constraint unit, which is used to obtain the last planned point, i.e., the end point, and assign the end point angular velocity to 0;

[0107] At the same time, obtain the planning point P under the deceleration look-back constraint i The speed is used to obtain the deceleration look-back constraint of each planning point and compare it with the second maximum allowable angular velocity constraint, and the minimum value of the two is taken as the final maximum allowable angular velocity constraint;

[0108] The control unit is used to calculate the yaw time interval between two adjacent planning points and determine the planning point P i-1 to Pi Determine whether the turning direction between them is counterclockwise. If so, the planned angular velocity takes the original value of the calculation result corresponding to the yaw time interval; otherwise, take the opposite value. At the same time, output speed control information, that is, the speed commands for the left and right wheels.

[0109] Furthermore, traverse each planned point to establish a maximum angular velocity constraint, and the corresponding expression is:

[0110] ω i ←min{||ω max ||,||ω limit ||},

[0111] where,

[0112] ||ω max || is the magnitude of the maximum angular velocity that can be achieved to satisfy the kinematic constraints of the robot body;

[0113] ||ω limit || is the magnitude of the maximum angular velocity speed limit obtained artificially;

[0114] ω i is the maximum allowable angular velocity at the planned point P i , and there is

[0115] Furthermore, for the angular velocity ω1 at the starting point, the corresponding expression is:

[0116] ω1=||ω current ||

[0117] where, ||ω current || is the magnitude of the current angular velocity of the mobile robot;

[0118] At the same time, assume that the angular acceleration a ω is constant within the interval between two adjacent planned points. Then, the expression for the yaw time interval corresponding to the adjacent planned points P i-1 to P i is:

[0119]

[0120] where,

[0121] Δs is the magnitude of the angular displacement between the planned points P i-1 and P i .

[0122] Originating from the same inventive concept, the present invention also designs a differential mobile robot loaded with a computing and control device, characterized in that the computing and control device includes: a memory and a processor, the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to execute the in-place yaw speed planning method of the differential mobile robot.

[0123] Originating from the same inventive concept, the present invention also designs a computer-readable storage medium, characterized in that the computer-readable storage medium stores computer instructions, and the computer instructions are used to cause a computer to execute the in-place yaw speed planning method of the differential mobile robot.

[0124] According to the foregoing specific technical solutions, the overall concept of the present invention is: the establishment process of the speed constraint corresponding to the present invention mainly consists of three parts. 1. First, consider the maximum angular velocity limited by the robot performance and the maximum angular velocity obtained according to the working conditions. 2. Secondly, according to the angular velocities at the planning start point and the end point, ensure that the speed limits actually achievable according to the performance limitations, the maximum angular acceleration and deceleration are used to establish the acceleration preview limit and the deceleration postview limit, so as to ensure that from the planning start point to the planning end point, the speed of each planning point can actually be reached through acceleration / deceleration. 3. Finally, perform the three-part constraint calculation in sequence, and take the smaller value each time, and finally the maximum allowable speed can be obtained.

[0125] The present invention has the following effects:

[0126] First, for the need of tracking a first-order differentiable path with discontinuous first or second derivative (i.e., the path is continuous but the curvature is discontinuous), the prior art solutions use curve fitting and nonlinear programming methods to optimize and smooth the path. Such methods are computationally complex, consume a large amount of computing power resources, and there is accuracy loss during the fitting process, resulting in a large deviation between the fitted path and the original path, and the traveling space is not completely controllable, which is not suitable for the situation where the traveling space is limited or a predetermined path needs to be strictly executed. Through the above technical solutions, the present invention realizes that without performing complex path smoothing operations, it can ensure that the mobile robot accurately tracks on any continuous path, and the yaw time is predictable, and the tracking motion can be controlled more real-time, accurately and effectively.

[0127] Secondly, for the need to adjust the posture for specific occasions, the existing technical solutions perform multi-segment speed adjustment by obtaining the acceleration and deceleration points in the corresponding intervals during the movement process. Such methods have poor controllability, and the drawback is that it is difficult to ensure the accuracy of the planning due to the acquisition of the interval acceleration and deceleration points. Through the above technical solutions, the present invention realizes the constraint on the speed planning of each planning point, including using the kinematic constraints of the mobile robot body, speed limit information, acceleration preview limit, and deceleration postview limit, which can provide a more stable and controllable in-place yaw speed curve to meet the working needs in narrow work sites or specific occasions, effectively improving the operation efficiency.

[0128] At the same time, for the need to interact with other devices, such as vision, robotic arms, etc., the present invention realizes the steering speed limit at different positions by obtaining the speed limit ω limit , effectively improving the flexibility of the process flow design.

[0129] The in-place yaw speed planning method for the differential mobile robot proposed by the present invention can obtain good speed planning effects in the following scenarios, such as:

[0130] Scenario 1: When there are multiple production lines in the factory, the mobile robot needs to travel strictly along the specified continuous path. When the curvature is discontinuous at the path connection, it is necessary to stop and adjust its own posture to ensure accurate tracking without affecting other processes.

[0131] Scenario 2: When the factory handling mobile robot reaches the specified work position, it needs to adjust its posture to a specific yaw angle to facilitate the docking and transfer of goods.

[0132] Scenario 3: When the mobile robot enters the station for charging, it needs to adjust the yaw angle to connect to the charging pile interface.

[0133] Scenario 4: For some work positions that need to interact with other devices, it is necessary to artificially limit the running speed of the mobile robot.

[0134] The above-disclosed are only the preferred embodiments of the present invention. Of course, the scope of the rights of the present invention cannot be limited thereby. Therefore, equivalent changes made according to the claims of the present invention still fall within the scope covered by the present invention.

Claims

1. A method for planning the yaw speed of a differential mobile robot in place, characterized in that, Including: Step 1, obtain in-situ yaw information; Step 2, discretize the path into a series of planned points, and traverse each planned point to establish the maximum angular velocity constraint of each planned point, that is, the first maximum allowable angular velocity constraint; Step 3, obtain the angular velocity ω1 of the first planned point, that is, the starting point; Step 4: Obtain the planned point P under the acceleration look-ahead limit i Obtain the angular velocity of i to get the angular velocity of each planned point under the acceleration look-ahead constraint, compare it with the first maximum allowable angular velocity constraint, and take the minimum value as the second maximum allowable angular velocity constraint; Step 5, obtain the last planned point, that is, the end point, and assign the end point angular velocity to 0; Step 6: Obtain the planned point P under the deceleration look-ahead limit i to obtain the deceleration look-ahead constraint for each planned point and compare it with the second maximum allowable angular velocity constraint, and take the minimum of the two as the final maximum allowable angular velocity constraint; Step 7, calculate the yaw time interval between two adjacent planned points; Step 8, determine the planned point P i-1 to P i Whether the turning direction between them is counterclockwise. If so, the planned angular velocity takes the original value of the calculation result corresponding to Step 7; otherwise, it takes the opposite value. Step 9, output speed control information, that is, the speed commands of the left and right wheels.

2. The speed planning method for the differential mobile robot to perform in-situ yaw as described in claim 1, characterized in that The aforementioned in-place yaw information includes an initial yaw angle θ start and a target yaw angle θ target , an angular displacement Δθ, and a steering direction.

3. A differential mobile robot in-situ yaw speed planning method according to claim 1, characterized in that Traverse each planned point to establish a maximum angular velocity constraint, and the corresponding expression is: ω i ← min{||ω max ||, ||ω limit ||}, Wherein, ||ω max || is the magnitude of the maximum angular velocity that can be achieved to satisfy the kinematic constraints of the robot body; ||ω limit || is the magnitude of the maximum angular velocity speed limit obtained artificially; ω i is the maximum allowable angular velocity at the planned point P i and there is 4. The method for planning the in-situ yaw rate of a differential mobile robot according to claim 1, wherein, The angular velocity ω1 of the starting point, and the corresponding expression is: ω1 = ||ω current || where ||ω current || is the magnitude of the current angular velocity of the mobile robot.

5. A differential mobile robot in-situ yaw speed planning method according to claim 3, characterized in that Assume that the angular acceleration a is constant within the interval between two adjacent planned points ω Then, the expression for the yaw time interval corresponding to the adjacent planned points P i-1 to P i is as follows: Wherein, Δs is the planning point P i-1 and P i The modulus of the angular displacement between them.

6. A differential mobile robot in-situ yaw speed planning system, characterized in that, Including: An information acquisition unit, wherein the information acquisition unit is used to acquire in-situ yaw information, and the in-situ yaw information includes an initial yaw angle θ start and a target yaw angle θ target , an angular displacement Δθ, and a steering direction; An information preprocessing unit, and the aforementioned information preprocessing unit is used to discretize the path into a series of planned points, and traverse each planned point to establish the maximum angular velocity constraint of each planned point, that is, the first maximum allowable angular velocity constraint; The first angular velocity constraint unit, where the first angular velocity constraint unit is used to obtain the angular velocity ω1 of the first planned point, i.e., the starting point; and obtain the angular velocity of the planned point P under the acceleration look-ahead limit to obtain the angular velocity of each planned point under the acceleration look-ahead constraint, and compare it with the first maximum allowable angular velocity constraint, and take the minimum value as the second maximum allowable angular velocity constraint; i and compare it with the first maximum allowable angular velocity constraint, and take the minimum value as the second maximum allowable angular velocity constraint; The second angular velocity constraint unit, where the second angular velocity constraint unit is used to obtain the last planned point, i.e., the end point, and assign the end point angular velocity to 0; at the same time, obtain the speed of the planned point P i under the deceleration look-ahead limit to obtain the deceleration look-ahead constraint of each planned point and compare it with the second maximum allowable angular velocity constraint, and take the minimum of the two as the final maximum allowable angular velocity constraint; A control unit, which is used to calculate the yaw time interval between two adjacent planned points and judge the planned point P i-1 to P i whether the steering direction between them is counterclockwise. If so, the planned angular velocity takes the original value of the calculation result corresponding to the yaw time interval; otherwise, it takes the opposite value; at the same time, output speed control information, that is, the speed commands of the left and right wheels.

7. A differential mobile robot in-situ yaw speed planning system according to claim 6, characterized in that Traverse each planned point to establish a maximum angular velocity constraint, and the corresponding expression is: ω i ← min{||ω max ||, ||ω limit ||}, Wherein, ||ω max || is the magnitude of the maximum angular velocity that can be achieved to satisfy the kinematic constraints of the robot body; ||ω limit || is the magnitude of the maximum angular velocity limit obtained artificially; ω i is the maximum allowable angular velocity at the planned point P i and there is 8. The in-place yaw speed planning system for a differential mobile robot according to claim 6, characterized in that, The angular velocity ω1 of the starting point, and the corresponding expression is: ω1 = ||ω current || where ||ω current || is the magnitude of the current angular velocity of the mobile robot; Meanwhile, it is assumed that the angular acceleration a ω is constant within the interval between two adjacent planned points. Then, the expression for the yaw time interval corresponding to the adjacent planned points P i-1 to P i is as follows: Wherein, Δs is the planning point P i-1 and P i The modulus of the angular displacement between.

9. A differential mobile robot device loaded with a computing and control device, characterized in that, The calculation control device includes: a memory and a processor, the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to execute the differential mobile robot in-situ yaw speed planning method according to any one of claims 1 to 5.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions, and the computer instructions are used to cause a computer to execute the differential mobile robot in-situ yaw speed planning method according to any one of claims 1 to 5.

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