Motion control method and device of multi-legged rescue robot based on leg distribution optimization

Abstract

The application provides a kind of based on supporting leg distribution optimization's multi-legged rescue robot motion control method and device, the based on supporting leg distribution optimization's multi-legged rescue robot motion control method includes: obtaining the centroid coordinate point of multi-legged rescue robot;In the case where the motion acceleration of the hydraulic device of multi-legged rescue robot is less than acceleration threshold value, determine the centroid coordinate point as the zero moment point of multi-legged rescue robot;Based on the vertical distance of the support area associated with the zero moment point and multiple supporting legs, determine the safety margin of multi-legged rescue robot, and in the case where the safety margin is kept maximum by adjusting the posture of mechanical arm and target supporting leg, obtain the adjustment increment of multi-legged rescue robot.The method of the application can adaptively adjust the posture of the robot according to the terrain, improve the automation degree and safety of multi-legged rescue robot in complex terrain.

Description

Technical Field

[0001] The present invention relates to the technical field of robot automatic control, and in particular to a motion control method and device for a multi-legged rescue robot based on leg distribution optimization. Background Art

[0002] Multi-legged rescue robots can operate in complex terrain environments, reducing the risk of life and property losses to rescue workers.

[0003] In related technologies, the control parameters of the robot are usually adjusted according to the specific terrain environment, and then the leg distribution is adjusted. When the terrain is more complex, the control parameters need to be input multiple times, the operation is cumbersome, and the degree of automation is low, which cannot meet the operational needs of multi-legged rescue robots in complex terrain. Summary of the Invention

[0004] The present invention provides a motion control method and device for a multi-legged rescue robot based on leg distribution optimization, which is used to solve the defects of the prior art multi-legged rescue robots in complex terrain, such as cumbersome operation and low degree of automation, and improve the degree of automation and safety of the multi-legged rescue robots in complex terrain.

[0005] The present invention provides a multi-legged rescue robot motion control method based on leg distribution optimization, which is applied to the multi-legged rescue robot. The multi-legged rescue robot includes a mechanical arm and multiple legs, including:

[0006] Obtaining the center of mass coordinates of the multi-legged rescue robot;

[0007] When the movement acceleration of the hydraulic components of the multi-legged rescue robot is less than an acceleration threshold, determining the center of mass coordinate point as the zero moment point of the multi-legged rescue robot;

[0008] determining a safety margin of the multi-legged rescue robot based on a vertical distance between the zero-moment point and a support area associated with the plurality of legs, and obtaining an adjustment increment of the multi-legged rescue robot while controlling the safety margin to be maximized by adjusting the postures of the robotic arm and the target leg;

[0009] The adjustment increment is used to control the motion posture of the multi-legged rescue robot, the support area is determined based on the contact positions of the multiple legs and the bottom surface, and the target leg belongs to the multiple legs.

[0010] According to a multi-legged rescue robot motion control method based on leg distribution optimization provided by the present invention, the target leg is the front leg of the multi-legged rescue robot, and the front leg includes three degrees of freedom;

[0011] The adjustment increment of the multi-legged rescue robot is obtained by adjusting the posture of the mechanical arm and the target leg to control the safety margin to be maximum.

[0012] The adjustment increment of the front leg is obtained by adjusting the swing angle of the second degree of freedom of the front leg to control the safety margin to be maximum.

[0013] According to the multi-legged rescue robot motion control method based on leg distribution optimization provided by the application, the mechanical arm has a swing joint and a boom joint.

[0014] The adjustment increment of the multi-legged rescue robot is obtained by adjusting the posture of the mechanical arm and the target leg to control the safety margin to be maximum.

[0015] The adjustment increment of the mechanical arm is obtained by adjusting the swing joint and the boom joint of the mechanical arm to control the safety margin to be maximum.

[0016] According to the multi-legged rescue robot motion control method based on leg distribution optimization provided by the application, the target leg is a rear leg of the multi-legged rescue robot, the rear leg includes three degrees of freedom, and the method further includes:

[0017] Obtaining motion parameters of the multi-legged rescue robot, the motion parameters including a moving speed of a vehicle body center of the multi-legged rescue robot, a motion direction, a wheel rotation radius of the rear leg, and a degree of freedom rotation angle.

[0018] The angular velocity of the wheel corresponding to the rear leg is determined by using the following formula:

[0019]

[0020]

[0021] wherein ω i is the angular velocity of the wheel, is the moving speed of the vehicle body center, v i is a speed related to the moving speed of the vehicle body center for wheel steering control, r i is the wheel rotation radius of the i-th wheel of the rear leg, S i is a unit vector in the rolling direction of the wheel, is a pseudo-inverse of a Jacobian matrix, q i is the rotation angle of the i-th degree of freedom of the rear leg.

[0022] According to the multi-legged rescue robot motion control method based on leg distribution optimization provided by the application, the swing angle is determined by using the following formula:

[0023]

[0024] wherein r is the wheel turning radius of the front leg, β is the swing angle, L x is the distance between the zero moment point and the first region, the first region is the boundary line corresponding to the front leg in the support region, L y is the distance between the zero moment point and the second region, the first region is the boundary line corresponding to the front leg and the rear leg in the support region, (x c , y c ) is the horizontal coordinate and the vertical coordinate of the center of mass coordinate point.

[0025] According to the multi-legged rescue robot motion control method based on leg distribution optimization provided by the application, the plurality of legs includes two front legs and two rear legs, and the method further includes:

[0026] In the case that the multi-legged rescue robot is in a three-point support state, the following formula is applied to keep the multi-legged rescue robot in a balanced state:

[0027] F lf,d = F rf,d = 0.5(F lf +F rf )

[0028] F lh,d = F rh,d = 0.5(F lh +F rh )

[0029] wherein in the case that the multi-legged rescue robot is determined to be in a three-point support state based on the mechanical arm and the two front legs, F lf，d and F rf，d are the expected forces of the two front legs, F lf and F rf are the actual forces of the two front legs; in the case that the multi-legged rescue robot is determined to be in a three-point support state based on the mechanical arm and the two rear legs, F lh , d and F rh，d are the expected forces of the two rear legs, F lh and F rh are the actual forces of the two rear legs, wherein d is an expected value.

[0030] According to the multi-legged rescue robot motion control method based on leg distribution optimization provided by the application, the adjustment increment of the multi-legged rescue robot is obtained by adjusting the posture of the mechanical arm and the target leg to control the maximum safety margin, including:

[0031] The adjustment increment of the multi-legged rescue robot is obtained by adjusting the posture of the robotic arm through the first adjustment cycle and adjusting the posture of the target leg through the second adjustment cycle to control the safety margin to be kept maximum; wherein, the first adjustment cycle is greater than the second adjustment cycle.

[0032] The present invention also provides a multi-legged rescue robot motion control device based on leg distribution optimization, the device comprising:

[0033] An acquisition module, configured to acquire a center of mass coordinate point of the multi-legged rescue robot, wherein the multi-legged rescue robot includes a mechanical arm and a plurality of legs;

[0034] A first processing module is configured to determine, when the motion acceleration of the hydraulic components of the multi-legged rescue robot is less than an acceleration threshold, the center-of-mass coordinate point as a zero-torque point of the multi-legged rescue robot;

[0035] a second processing module, configured to determine a safety margin of the multi-legged rescue robot based on a vertical distance between the zero-moment point and a support area associated with the plurality of legs, and obtain an adjustment increment of the multi-legged rescue robot while controlling the safety margin to be maximized by adjusting the postures of the robotic arm and the target leg;

[0036] The adjustment increment is used to control the motion posture of the multi-legged rescue robot, the support area is determined based on the contact positions of the multiple legs and the bottom surface, and the target leg belongs to the multiple legs.

[0037] The present invention also provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and runnable on the processor. When the processor executes the program, a multi-legged rescue robot motion control method based on leg distribution optimization as described above is implemented.

[0038] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the multi-legged rescue robot motion control method based on leg distribution optimization as described above is implemented.

[0039] The present invention also provides a computer program product, comprising a computer program, which, when executed by a processor, implements any of the above-described multi-legged rescue robot motion control methods based on leg distribution optimization.

[0040] The present invention provides a multi-legged rescue robot motion control method and device based on leg distribution optimization. When the motion acceleration of the hydraulic device of the multi-legged rescue robot is less than the acceleration threshold, the center of mass coordinate point is approximated as the zero torque point of the multi-legged rescue robot. Based on the vertical distance between the zero torque point and the support area associated with multiple legs, the safety margin of the multi-legged rescue robot is determined. By adjusting the posture of the robotic arm and the target leg to control the safety margin to be kept at the maximum, the adjustment increment of the multi-legged rescue robot is obtained. The posture of the robot can be adaptively adjusted according to the terrain, thereby improving the degree of automation and safety of the multi-legged rescue robot in complex terrain. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to 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.

[0042] Figure 1 This is one of the flow charts of the multi-legged rescue robot motion control method based on leg distribution optimization provided by the present invention;

[0043] Figure 2 Schematic diagram of the distribution of the outrigger positions and zero moment points provided by the present invention;

[0044] Figure 3 It is a schematic diagram of the projection of the wheels corresponding to the mechanical arm and legs provided by the present invention on a plane;

[0045] Figure 4 Schematic diagram of the structure of the multi-legged rescue robot motion control device based on leg distribution optimization provided by the present invention;

[0046] Figure 5 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0047] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0048] The following combination Figures 1-4 The present invention describes a multi-legged rescue robot motion control method and device based on leg distribution optimization.

[0049] Figure 1 The present invention provides a flow chart of a multi-legged rescue robot motion control method based on leg distribution optimization. The multi-legged rescue robot motion control method based on leg distribution optimization is applied to a multi-legged rescue robot including a robotic arm and multiple legs, and includes the following steps:

[0050] Step 110: Obtain the center of mass coordinates of the multi-legged rescue robot.

[0051] In this step, the multi-legged rescue robot includes a robotic arm and multiple legs. For example, a quadruped robot includes two front legs, two rear legs and a robotic arm.

[0052] In this embodiment, each leg may include multiple degrees of freedom (joints). For example, each leg of the quadruped rescue robot includes three degrees of freedom. The third degree of freedom of the front leg is used to control the lifting and lowering of the robot's claws, which can prevent slipping on sloping terrain. The third degree of freedom of the rear leg is used for steering the wheels, and the degree of freedom length is relatively small. The main movement of each leg is affected by the first two degrees of freedom, which include a rotation joint along the Y axis and a rotation joint along the Z axis.

[0053] In this embodiment, the degree of freedom of rotation along the Y-axis is mainly used to raise and lower the robot legs for ground height adjustment, and the degree of freedom of rotation along the Z-axis is mainly used to adjust the support range of the vehicle body to improve safety.

[0054] It should be noted that during wheeled driving, the front wheels do not have a steering function and can only remain consistent with the X-axis direction of the vehicle body.

[0055] In this embodiment, the center of mass coordinate point of the multi-legged rescue robot can be measured by a gravity measuring instrument (for example, a mass center of mass measuring instrument, etc.) installed on the robot body, and can also be obtained through measurement algorithms such as mechanical gravity method and static center of mass measurement.

[0056] In this embodiment, the center of mass coordinate point includes a spatial rectangular coordinate, and the origin of the spatial rectangular coordinate system is determined according to the distribution area of ​​the legs. For example, the quadruped rescue robot includes four legs (AD) and a robotic arm (E), and AD is connected in sequence to obtain a support area. With the center of the support area as the origin, a spatial rectangular coordinate system is created in the three-dimensional direction, and then the center of mass coordinate (x c ,y c , z c ).

[0057] In this embodiment, the center of mass coordinate point of the robot is not fixed, and the position of the center of mass coordinate point is related to the movement posture of the robot, specifically, the posture of the legs and the posture of the robot arm.

[0058] Step 120: When the movement acceleration of the hydraulic components of the multi-legged rescue robot is less than the acceleration threshold, determine the center of mass coordinate point as the zero torque point of the multi-legged rescue robot.

[0059] In this step, the zero torque point of the rescue robot can be calculated through a real-time dynamic stability determination method, and then the required robot leg distribution data can be determined.

[0060] In this embodiment, the dynamic stability determination method includes a zero-moment point stability determination method and the like.

[0061] In this embodiment, the process of calculating the zero moment point using the zero moment point stability determination method is as follows:

[0062] 1) Use the following formula to determine the zero moment point (x p ,y p , z p ):

[0063]

[0064]

[0065] Among them, (x c ,y c , z c ) is the coordinate point of the center of mass, and are the accelerations of the robot body in the x-axis, y-axis and z-axis directions respectively.

[0066] 2) Hydraulic devices move slowly and have a high acceleration. and The zero moment point and the center of mass coordinate point are close, so the coordinates of the two can be approximated. That is, when the movement acceleration of the hydraulic device of the multi-legged rescue robot is less than the acceleration threshold, the center of mass coordinate point corresponding to the multi-legged rescue robot is used as the zero moment point.

[0067] It should be noted that when the movement acceleration of the hydraulic components of the multi-legged rescue robot is less than the acceleration threshold, the vehicle body is basically in a static equilibrium state. In this case, the center of gravity of the equipment needs to be kept within the support range of each leg and the hydraulic manipulator arm (when the hydraulic manipulator arm supports the ground).

[0068] Step 130: Determine the safety margin of the multi-legged rescue robot based on the vertical distance between the zero torque point and the support area associated with the multiple legs, and obtain the adjustment increment of the multi-legged rescue robot by adjusting the posture of the robotic arm and the target leg to control the safety margin to be kept as maximum; wherein the adjustment increment is used to control the motion posture of the multi-legged rescue robot, the support area is determined based on the contact position of the multiple legs with the bottom surface, and the target leg belongs to the multiple legs.

[0069] In this step, the adjustment increment includes the change in the posture adjustment parameters of the manipulator arms and legs of the multi-legged rescue robot, such as the deflection angle, the deflection angular velocity, and the body running speed.

[0070] In this step, when determining the safety margin of the multi-legged rescue robot, the shortest vertical distance between the zero-torque point of the vehicle body and the support area of ​​the outriggers can be set as the safety margin.

[0071] For example, a quadruped rescue robot consists of four legs (AD) and a robotic arm (E). Connecting AD in sequence gives a support area ABCD. The zero torque point of the robot is (x p ,y p , z p ), at time t0, the shortest vertical distance from the robot's zero torque point to the support area is d0, and the robot's safety margin is d0.

[0072] In this embodiment, the manner of adjusting the posture of the robot includes the following:

[0073] 1) Adjust the robot's posture by controlling the posture of the robot's target leg;

[0074] 2) Adjust the robot's posture by controlling the posture of the robot's target legs and the posture of the robotic arm.

[0075] In this embodiment, the target legs include the front legs of the multi-legged rescue robot, and the front legs of the quadruped rescue robot include two.

[0076] Taking the robot's posture adjustment by controlling the posture of multiple legs as an example, the quadruped rescue robot includes two legs (LF and RF) and two rear legs (LH and RH). The swing angle of the second joint of the front leg LF is adjusted so that the zero torque point of the robot is (x p ,y p , z p ) to the support area LF-RF-LH-RH is the largest.

[0077] In this embodiment, the posture of the robot can also be adjusted by adjusting the posture of the manipulator arm in combination with the posture adjustment of the legs. For example, the rotary joint and the boom joint of the hydraulic manipulator arm are adjusted so that the zero torque point of the robot is (x p ,y p , z p ) to the support area LF-RF-LH-RH is the largest.

[0078] The multi-legged rescue robot motion control method based on leg distribution optimization of an embodiment of the present invention, when the motion acceleration of the hydraulic device of the multi-legged rescue robot is less than the acceleration threshold, takes the center of mass coordinate point as the zero torque point of the multi-legged rescue robot, and determines the safety margin of the multi-legged rescue robot based on the vertical distance between the zero torque point and the support area associated with multiple legs. By adjusting the posture of the robotic arm and the target leg to control the safety margin to be maximum, the adjustment increment of the multi-legged rescue robot is obtained, and the posture of the robot can be adaptively adjusted according to the terrain, thereby improving the degree of automation and safety of the multi-legged rescue robot in complex terrain.

[0079] In some embodiments, the target leg is the front leg of a multi-legged rescue robot, and the front leg includes three degrees of freedom; while adjusting the posture of the robotic arm and the target leg to control the safety margin to be maximum, the adjustment increment of the multi-legged rescue robot is obtained, including: while adjusting the swing angle of the second degree of freedom of the front leg to control the safety margin to be maximum, the adjustment increment of the front leg is obtained.

[0080] In this embodiment, the target legs are the front legs of the multi-legged rescue robot. For example, the quadruped rescue robot includes two legs (LF and RF) and two rear legs (LH and RH), and the target legs include LF and RF.

[0081] In this embodiment, in order to increase the maximum safety margin, the following method can be used to determine the angle value of the hind leg joint rotation along the Z axis.

[0082] 1) Control the multi-legged robot's manipulator arm so that the zero torque point is close to the chassis' rotation center;

[0083] 2) By adjusting the swing angle of the second joint of the leg LF, the relative position of the leg LF and other legs is adjusted to keep the vertical distance from the zero moment point to the support area at the maximum.

[0084] 3) By adjusting the swing angle of the second joint of the other leg RF, the relative position of the leg RF and the other legs is adjusted so that the vertical distance from the zero moment point to the two adjacent boundary lines of the support area (LF-RF-LH-RH) is kept at the maximum.

[0085] 4) repeat steps 2 and 3 in a preset control cycle to obtain the adjustment increment of the corresponding joint of the robot.

[0086] In this embodiment, the swing angle or deflection angle of the rear support leg of the robot is obtained from the advancing direction of the body of the robot.

[0087] The multi-legged rescue robot motion control method based on support leg distribution optimization of the embodiment of the application determines the safety margin of the robot by the shortest distance from the zero moment point to the support area, and determines multiple support leg distribution states by adjusting the pose of the front support leg of the robot, so that the robot maintains the maximum safety margin, and the safety of the robot in complex terrain operation is improved.

[0088] In some embodiments, the robot arm has a swing joint and a boom joint; and the adjustment increment of the multi-legged rescue robot is obtained by adjusting the pose of the robot arm and the target support leg to control the safety margin to be the maximum, including: the adjustment increment of the robot arm is obtained by adjusting the swing joint and the boom joint of the robot arm to control the safety margin to be the maximum.

[0089] In this embodiment, in addition to adjusting the safety margin by adjusting the pose of the front support leg, the safety margin of the robot can also be adjusted by adjusting the body swing joint and the boom joint of the robot arm.

[0090] In this embodiment, the safety margin of the robot is adjusted by simultaneously adjusting the positions of the front support leg and the robot arm, and the steps are as follows:

[0091] 1) control the robot arm of the multi-legged robot to make the zero moment point close to the rotation center of the chassis;

[0092] 2) adjust the swing angle of the second joint of each of the two front support legs LF and RF to make the vertical distance from the zero moment point of the robot to the support area maximum;

[0093] 3) in the case that the zero moment point is within the range of the support area, the swing joint and the boom joint of the robot arm are adjusted to make the vertical distance from the zero moment point to the support area maximum.

[0094] 4) repeat steps 2-3 in a preset control cycle to obtain the adjustment increment of the corresponding joint of the robot.

[0095] The multi-legged rescue robot motion control method based on support leg distribution optimization of the embodiment of the application determines the safety margin of the robot by the shortest distance from the zero moment point to the support area, and determines multiple support leg distribution states by simultaneously adjusting the pose of the front support leg and the robot arm to maintain the maximum safety margin of the robot, and further improves the safety of the robot in complex terrain operation.

[0096] In some embodiments, the target leg is a rear leg of a multi-legged rescue robot, and the rear leg includes three degrees of freedom. The method further includes: obtaining motion parameters of the multi-legged rescue robot, the motion parameters including the moving speed of the center of mass of the multi-legged rescue robot, the moving direction, the wheel radius of the rear leg, and the degree of freedom angle; and determining the angular velocity of the wheel corresponding to the rear leg using the following formula:

[0097]

[0098]

[0099] Among them, ω i is the angular velocity of the wheel, is the moving speed of the vehicle’s center of mass, v i The speed of the vehicle's center of mass is the speed of the wheel steering control, r i is the turning radius of the i-th wheel of the rear outrigger, S i is the unit vector of the wheel rolling direction, is the pseudo-inverse of the Jacobian matrix, q i is the rotation angle of the i-th degree of freedom of the rear support leg.

[0100] In this embodiment, the adjustment increment includes motion variables such as the angular velocity of the wheels and the moving speed of the center of mass of the vehicle body.

[0101] In this embodiment, when the multi-legged rescue robot is moving forward, it is also necessary to determine the angular velocity of the wheels on the supporting legs according to the movement of the supporting legs.

[0102] In this embodiment, when the multi-legged rescue robot is traveling on a steep slope, there is a risk of slipping if it relies solely on the friction of the wheels touching the ground. The robot needs to rely on the robotic arms and hind leg support claws to support the ground in turn to prevent the vehicle body from sliding down the slope. If the slope is too steep, the friction on the wheels is not enough to push the vehicle body up the steep slope, and the robotic arms need to provide thrust. When traveling on steep slopes, the robot only moves forward when pushed by the robotic arms. When the robotic arms are lifted to find a new landing point, the support claws are used to prevent slipping.

[0103] In this embodiment, during the pushing process of the manipulator, the four legs keep in contact with the ground. The multi-legged rescue robot still needs active ground pressure control. For example, the friction force of the manipulator and the wheels jointly provides thrust along the up and down directions of the slope. The manipulator also provides partial support along the normal direction of the slope. The support force provided by the four legs of the vehicle body is mainly along the slope direction, and the maximum can reach mgcos(α). In this way, the main support force considered by the wheels is mg ⊥ , the friction provided by the wheel is μmg ⊥ , the thrust provided by the robotic arm is At the same time, the speed of the hydraulic manipulator end effector needs to be consistent with the walking speed of the vehicle.

[0104] In this embodiment, when the forward direction of the multi-legged rescue robot is controlled to be an upward / downward direction along the slope angle according to the user's operating instructions, the rotation axis of the wheel is still along the Z-axis direction of the vehicle body. It should be noted that the control method of the legs is consistent with that of wheeled driving, but when the robotic arm is extended forward, it is necessary to ensure that the distance between the center of gravity of the vehicle body and the boundary line corresponding to the two front legs in the support area is greater than the safety distance threshold to reduce the risk of the robot tipping forward.

[0105] The multi-legged rescue robot motion control method based on leg distribution optimization in an embodiment of the present invention obtains the motion parameters of the multi-legged rescue robot and applies the above formula to calculate the wheel angular velocity of each leg according to the forward speed of the vehicle body center of mass, thereby ensuring that the multi-legged rescue robot can move forward stably in complex terrain and improving safety.

[0106] In some embodiments, the swing angle is determined using the following formula:

[0107] rsinβ+L x / 2-x c =rcosβ+L y / 2-y c

[0108] Among them, r is the rotation radius of the front leg, β is the swing angle, L x is the distance between the zero moment point and the first area, the first area is the boundary line corresponding to the front leg in the support area, L y is the distance between the zero moment point and the second area, the first area is the boundary line corresponding to the front leg and the rear leg in the support area, (x c ,y c ) are the horizontal and vertical coordinates of the centroid coordinate point.

[0109] In this embodiment, the leg position distribution can be adjusted by adjusting the swing angle (deflection angle) of the second joint of the front leg. The deflection angle of the leg joint is related to the rotation radius of the front leg, the distance between the zero torque point and the support area, and the center of mass coordinate point.

[0110] Figure 2 This is a schematic diagram of the distribution of the support leg positions and zero moment points provided by the present invention. Figure 2 In the embodiment shown, the swing angle adjustment formula is applied to adjust the swing angles of the second joints of the two front legs LF and RF respectively, so as to maximize the vertical distance from the zero torque point of the robot to the support area (square area), thereby obtaining the maximum safety margin of the multi-legged rescue robot, where P c is the center of mass of the robot.

[0111] The multi-legged rescue robot motion control method based on leg distribution optimization in an embodiment of the present invention calculates the joint deflection angle of the robot's front legs through the rotation radius of the front legs, the distance between the zero torque point and the support area, and the center of mass coordinate point to ensure that the robot's safety margin is maximized, thereby improving the robot's motion safety.

[0112] In this embodiment, the plurality of legs include two front legs and two rear legs. The method further includes: when the multi-legged rescue robot is in a three-point support state, applying the following formula to keep the multi-legged rescue robot in a balanced state:

[0113] F lf,d =F rf,d =0.5(F lf +F rf )

[0114] F lh,d =F rh,d =0.5(F lh +F rh )

[0115] Among them, when the multi-legged rescue robot is determined to be in a three-point support state based on the mechanical arm and two front legs, F lf，d and F rf，d are the expected forces on the two front legs, F lf and F rf are the actual forces on the two front legs respectively; when the multi-legged rescue robot is determined to be in a three-point support state based on the robotic arm and the two rear legs, F lh，d and F rh，d are the expected forces on the two rear legs, F lh and F rh are the actual forces on the two rear legs, and d is the expected value.

[0116] Figure 3 This is a schematic diagram of the projection of the wheels corresponding to the mechanical arm and legs provided by the present invention on a plane. Figure 3 In the illustrated embodiment, the key to step-crossing control lies in the robot's independent support of the arms and front / rear wheels. Unlike steep slope driving, the support force of the arms lifts the front or rear legs to cross the step, creating a three-point support state. During this process, all three points must touch the ground. Ignoring the asymmetry of the vehicle body, only the support force of the two grounded wheels needs to be balanced, where S m1 and S m2 are the vertical distances between the center of mass and the corresponding edge of the support area, and CoM is the center of mass of the robot.

[0117] In this embodiment, when the multi-legged rescue robot crosses the stairs, the front legs LF and RF go up and down the stairs at the same time, and the hind legs LH and RH go up and down the stairs at the same time; during this process, the ground support force is provided by the robotic arm; since the y coordinate of the center of mass is approximately 0, the support point of the robotic arm is usually selected on the middle line of the vehicle body to balance the left and right rollover safety margins.

[0118] In this embodiment, the farther the support point of the robotic arm is, the farther the center of gravity of the vehicle body is from the edge of the support area (corresponding to the triangle), and the higher the safety margin for rollover; however, the robotic arm also needs sufficient range of motion at the support point to enable the front / rear legs to cross the steps; in addition, the support point of the robotic arm is usually selected on the farthest central axis that meets the range of motion.

[0119] In this embodiment, when the robotic arm pushes the vehicle body forward, the speed of the robotic arm and the wheel can be obtained according to the calculation formula corresponding to the angular velocity of the wheel.

[0120] The multi-legged rescue robot motion control method based on leg distribution optimization in an embodiment of the present invention maintains the multi-legged rescue robot in a balanced state according to the relationship between the expected force and the actual force of the legs when the multi-legged rescue robot is in a three-point support state, thereby realizing active ground pressure adjustment of the multi-legged rescue robot when walking in wheeled legs on uneven ground, so as to meet the stable support requirements of complex terrain driving.

[0121] In some embodiments, the adjustment increment of the multi-legged rescue robot is obtained by adjusting the posture of the robotic arm and the target leg to control the safety margin to be maximum, including: adjusting the posture of the robotic arm through a first adjustment cycle, and adjusting the posture of the target leg through a second adjustment cycle to control the safety margin to be maximum, thereby obtaining the adjustment increment of the multi-legged rescue robot; wherein the first adjustment cycle is greater than the second adjustment cycle.

[0122] In this embodiment, the first adjustment period and the second adjustment period can be set according to actual needs of the user.

[0123] In this embodiment, the postures of the robotic arm and the target leg can be adjusted periodically, wherein the adjustment periods of the robotic arm and the target leg are different. Specifically, the adjustment period of the robotic arm is greater than the adjustment period of the target leg.

[0124] The multi-legged rescue robot motion control method based on leg distribution optimization in an embodiment of the present invention adjusts the posture of the robotic arm through a first adjustment cycle, and adjusts the posture of the target leg through a second adjustment cycle to control the safety margin to remain maximum, reduce the oscillation during the adjustment process of the legs and robotic arm, and also improve the motion stability of the multi-legged rescue robot.

[0125] The multi-legged rescue robot motion control device based on leg distribution optimization provided by the present invention is described below. The multi-legged rescue robot motion control device based on leg distribution optimization described below and the multi-legged rescue robot motion control method based on leg distribution optimization described above can be referenced to each other.

[0126] Figure 4 This is a schematic diagram of the structure of the multi-legged rescue robot motion control device based on leg distribution optimization provided by the present invention. Figure 4 In the illustrated embodiment, the multi-legged rescue robot motion control device based on leg distribution optimization includes: an acquisition module 410 , a first processing module 420 and a second processing module 430 .

[0127] An acquisition module 410 is used to obtain the coordinate point of the center of mass of the multi-legged rescue robot, where the multi-legged rescue robot includes a robotic arm and multiple legs;

[0128] A first processing module 420 is configured to determine the center of mass coordinate point as a zero torque point of the multi-legged rescue robot when the motion acceleration of the hydraulic components of the multi-legged rescue robot is less than an acceleration threshold;

[0129] A second processing module 430 is configured to determine a safety margin of the multi-legged rescue robot based on a vertical distance between the zero-moment point and a support area associated with the plurality of legs, and obtain an adjustment increment of the multi-legged rescue robot while maximizing the safety margin by adjusting the postures of the manipulator arm and the target leg;

[0130] Among them, the adjustment increment is used to control the movement posture of the multi-legged rescue robot, the support area is determined based on the contact position of multiple legs with the bottom surface, and the target leg belongs to multiple legs.

[0131] The multi-legged rescue robot motion control device based on leg distribution optimization in an embodiment of the present invention determines the safety margin of the multi-legged rescue robot based on the center of mass coordinate point approximating the zero torque point of the multi-legged rescue robot when the motion acceleration of the hydraulic device of the multi-legged rescue robot is less than the acceleration threshold, based on the vertical distance between the zero torque point and the support area associated with multiple legs, and obtains the adjustment increment of the multi-legged rescue robot while controlling the safety margin to be maximized by adjusting the posture of the robotic arm and the target leg. The robot's posture can be adaptively adjusted according to the terrain, thereby improving the degree of automation and safety of the multi-legged rescue robot in complex terrain.

[0132] Figure 5 Schematic diagram of the structure of the electronic device provided by the present invention, such as Figure 5As shown, the electronic device may include: a processor 510, a communication interface 520, a memory 530, and a communication bus 540, wherein the processor 510, the communication interface 520, and the memory 530 communicate with each other via the communication bus 540. The processor 510 may call logic instructions in the memory 530 to execute a multi-legged rescue robot motion control method based on leg distribution optimization, the method comprising: obtaining a center of mass coordinate point of the multi-legged rescue robot; determining the center of mass coordinate point as a zero-torque point of the multi-legged rescue robot when the motion acceleration of the hydraulic components of the multi-legged rescue robot is less than an acceleration threshold; determining a safety margin of the multi-legged rescue robot based on a vertical distance between the zero-torque point and a support area associated with multiple legs, and obtaining an adjustment increment of the multi-legged rescue robot when the posture of the manipulator and the target leg is controlled to maintain a maximum safety margin; wherein the adjustment increment is used to control the motion posture of the multi-legged rescue robot, the support area is determined based on the contact position of the multiple legs with the bottom surface, and the target leg belongs to the multiple legs.

[0133] In addition, the logic instructions in the above-mentioned memory 530 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0134] On the other hand, the present invention also provides a computer program product, which includes a computer program, which can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the multi-legged rescue robot motion control method based on leg distribution optimization provided by the above methods, the method including: obtaining the center of mass coordinate point of the multi-legged rescue robot; when the motion acceleration of the hydraulic device of the multi-legged rescue robot is less than the acceleration threshold, determining the center of mass coordinate point as the zero torque point of the multi-legged rescue robot; determining the safety margin of the multi-legged rescue robot based on the vertical distance between the zero torque point and the support area associated with multiple legs, and obtaining the adjustment increment of the multi-legged rescue robot by adjusting the posture of the robotic arm and the target leg to control the safety margin to be maximum; wherein the adjustment increment is used to control the motion posture of the multi-legged rescue robot, the support area is determined based on the contact position of multiple legs with the bottom surface, and the target leg belongs to multiple legs.

[0135] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the multi-legged rescue robot motion control method based on leg distribution optimization provided by the above-mentioned methods, the method comprising: obtaining the center of mass coordinate point of the multi-legged rescue robot; when the motion acceleration of the hydraulic device of the multi-legged rescue robot is less than the acceleration threshold, determining the center of mass coordinate point as the zero torque point of the multi-legged rescue robot; determining the safety margin of the multi-legged rescue robot based on the vertical distance between the zero torque point and the support area associated with multiple legs, and obtaining the adjustment increment of the multi-legged rescue robot by adjusting the posture of the robotic arm and the target leg to control the safety margin to be kept as maximum; wherein the adjustment increment is used to control the motion posture of the multi-legged rescue robot, the support area is determined based on the contact position of multiple legs with the bottom surface, and the target leg belongs to multiple legs.

[0136] 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. They may be located in one place 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.

[0137] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, or of course, by hardware. Based on this understanding, the essence of the above technical solution or the part that contributes to the existing technology can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or certain parts of the embodiments.

[0138] 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.

Claims

1. A motion control method for a multi-legged rescue robot based on leg distribution optimization, applied to a multi-legged rescue robot comprising a robotic arm and a plurality of legs, characterized in that: include: Obtaining the center of mass coordinates of the multi-legged rescue robot; When the movement acceleration of the hydraulic components of the multi-legged rescue robot is less than an acceleration threshold, determining the center of mass coordinate point as the zero moment point of the multi-legged rescue robot; determining a safety margin of the multi-legged rescue robot based on a vertical distance between the zero-moment point and a support area associated with the plurality of legs, and obtaining an adjustment increment of the multi-legged rescue robot while controlling the safety margin to be maximized by adjusting the postures of the robotic arm and the target leg; The adjustment increment is used to control the motion posture of the multi-legged rescue robot, the support area is determined based on the contact positions of the multiple legs and the bottom surface, and the target leg belongs to the multiple legs.

2. The multi-legged rescue robot motion control method based on leg distribution optimization according to claim 1 is characterized in that: The target leg is the front leg of the multi-legged rescue robot, and the front leg includes three degrees of freedom; The step of obtaining an adjustment increment of the multi-legged rescue robot while controlling the safety margin to be kept at a maximum by adjusting the postures of the robotic arm and the target leg comprises: Under the condition that the safety margin is controlled to be kept at the maximum by adjusting the swing angle of the second degree of freedom of the front supporting leg, the adjustment increment of the front supporting leg is obtained.

3. The multi-legged rescue robot motion control method based on leg distribution optimization according to claim 1 is characterized in that: The robotic arm has a rotary joint and a boom joint; The step of obtaining an adjustment increment of the multi-legged rescue robot while controlling the safety margin to be kept at a maximum by adjusting the postures of the robotic arm and the target leg comprises: Under the condition that the safety margin is controlled to be kept at the maximum by adjusting the rotary joint and the boom joint of the robot arm, an adjustment increment of the robot arm is obtained.

4. The multi-legged rescue robot motion control method based on leg distribution optimization according to claim 1 is characterized in that: The target leg is a rear leg of the multi-legged rescue robot, and the rear leg includes three degrees of freedom. The method further includes: Acquire motion parameters of the multi-legged rescue robot, wherein the motion parameters include the moving speed of the body mass center of the multi-legged rescue robot, the moving direction, the rotation radius of the rear legs, and the degree of freedom angle; The angular velocity of the wheel corresponding to the rear outrigger is determined using the following formula: Among them, ω i is the angular velocity of the wheel, is the moving speed of the vehicle’s center of mass, v i The speed of the vehicle's center of mass is the speed of the wheel steering control, r i is the turning radius of the i-th wheel of the rear outrigger, S i is the unit vector of the wheel rolling direction, is the pseudo-inverse of the Jacobian matrix, q i is the rotation angle of the i-th degree of freedom of the rear support leg.

5. The multi-legged rescue robot motion control method based on leg distribution optimization according to claim 2 is characterized in that: The swing angle is determined using the following formula: rsinβ+L x / 2-x c =rcosβ+L y / 2-y c Where r is the rotation radius of the front leg, β is the swing angle, L x is the distance between the zero moment point and the first area, the first area is the boundary line corresponding to the front leg in the support area, L y is the distance between the zero moment point and the second area, the first area being the boundary line corresponding to the front leg and the rear leg in the support area, (x c ,y c ) are the horizontal and vertical coordinates of the centroid coordinate point.

6. The multi-legged rescue robot motion control method based on leg distribution optimization according to claim 1 is characterized in that: The plurality of legs includes two front legs and two rear legs, the method further comprising: When the multi-legged rescue robot is in a three-point support state, the following formula is applied to keep the multi-legged rescue robot in a balanced state: F lf,d =F rf,d =0.5(F lf +F rf ) F lh,d =F rh,d =0.5(F lh +F rh ) Wherein, when it is determined based on the mechanical arm and the two front legs that the multi-legged rescue robot is in a three-point support state, F lf，d and F rf，d are the expected forces on the two front legs, F lf and F rf are the actual forces on the two front legs respectively; when it is determined that the multi-legged rescue robot is in a three-point support state based on the mechanical arm and the two rear legs, F lh，d and F rh，d are the expected forces on the two rear legs, F lh and F rh are the actual forces on the two rear legs, and d is the expected value.

7. The multi-legged rescue robot motion control method based on leg distribution optimization according to claim 1 is characterized in that: The step of adjusting the postures of the manipulator arm and the target leg to control the safety margin to be kept at a maximum, thereby obtaining an adjustment increment of the multi-legged rescue robot, comprises: By adjusting the posture of the robotic arm through a first adjustment cycle and adjusting the posture of the target leg through a second adjustment cycle to control the safety margin to be kept at the maximum, an adjustment increment of the multi-legged rescue robot is obtained; wherein, the first adjustment cycle is greater than or equal to the second adjustment cycle.

8. A multi-legged rescue robot motion control device based on leg distribution optimization, characterized in that: The device comprises: An acquisition module, configured to acquire a center of mass coordinate point of the multi-legged rescue robot, wherein the multi-legged rescue robot includes a mechanical arm and a plurality of legs; A first processing module is configured to determine, when the motion acceleration of the hydraulic components of the multi-legged rescue robot is less than an acceleration threshold, the center-of-mass coordinate point as a zero-torque point of the multi-legged rescue robot; a second processing module, configured to determine a safety margin of the multi-legged rescue robot based on a vertical distance between the zero-moment point and a support area associated with the plurality of legs, and obtain an adjustment increment of the multi-legged rescue robot while controlling the safety margin to be maximized by adjusting the postures of the robotic arm and the target leg; The adjustment increment is used to control the motion posture of the multi-legged rescue robot, the support area is determined based on the contact positions of the multiple legs with the ground, and the target leg belongs to the multiple legs.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the multi-legged rescue robot motion control method based on leg distribution optimization as described in any one of claims 1 to 6 is implemented.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the multi-legged rescue robot motion control method based on leg distribution optimization as described in any one of claims 1 to 6 is implemented.

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