CN-122008293-A - Prejudgment distance and gesture planning method and device before grabbing of humanoid robot

CN122008293ACN 122008293 ACN122008293 ACN 122008293ACN-122008293-A

Abstract

The application provides a pre-judging distance and gesture planning method and device before grabbing a humanoid robot, and the method and device comprise the steps of setting moment monitoring parameters of joints of each double arm based on initial bearing moment, monitoring, taking the maximum deviation between an actual monitoring moment value of the joint at a near centroid side and a preset initial bearing moment reference value as moment peak value difference of the joint at the near centroid side, adjusting moment distribution according to the moment peak value difference to reduce vertical supporting moment at the near centroid side and increase compensating moment at the far centroid side, determining target moment values of the joints, generating a joint moment distribution scheme, executing the joint moment distribution scheme, verifying contact state of a contact at the near centroid side, comparing local deformation quantity at the near centroid side with a preset slippage instability limit value, and outputting moment peak value control results containing the current moment balance state of the double arm.

Inventors

SHAN JIE
ZHANG WENBO
CHEN KAI
Liang Xinfen
ZHANG QIANHU

Assignees

深圳市长盈机器人有限公司
深圳市长盈精密技术股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260127

Claims (10)

1. The method for planning the prejudgment distance and the gesture before grabbing the humanoid robot is characterized by comprising the following steps: acquiring initial grabbing data of an object contact point, acquiring a longitudinal offset distance of an object mass center and an elastic modulus of a surface of a side near the mass center, and determining an initial bearing moment of an arm of the side near the mass center according to the longitudinal offset distance of the mass center and the elastic modulus of the surface of the side near the mass center; Setting moment monitoring parameters of all joints of the double arms based on the initial bearing moment, and monitoring, wherein the maximum deviation between the actual monitoring moment value of the near-centroid side joint and a preset initial bearing moment reference value is used as the moment peak value difference of the near-centroid side joint; And adjusting moment distribution according to the moment peak value difference to reduce the near-centroid side vertical supporting moment and increase the far-centroid side compensating moment, determining the target moment value of each joint, and generating a joint moment distribution scheme.
2. The method for planning a pre-grasp pre-judgment distance and pose of a humanoid robot according to claim 1, wherein the determining an initial bearing moment of a near-centroid side arm according to the centroid longitudinal offset distance and the near-centroid side surface elastic modulus comprises: And analyzing the relation between the normal deformation quantity and the contact stress of the object contact point by combining the longitudinal offset distance of the centroid and the elastic modulus of the surface of the side of the near centroid, obtaining the stress distribution state of the contact area, judging whether the contact stress of the side of the near centroid exceeds a preset material elastic limit threshold value according to the stress distribution state, determining the initial bearing moment of the arm at the side of the near centroid according to the centroid offset proportion if the contact stress of the side of the near centroid does not exceed the preset material elastic limit threshold value, and reducing the distribution proportion of the moment at the side of the near centroid and increasing the compensation bearing moment of the arm at the side of the far centroid if the contact stress of the side of the near centroid exceeds the preset material elastic limit threshold value.
3. The method for planning the pre-judgment distance and the gesture before grabbing of the humanoid robot according to claim 1, wherein the setting and monitoring of the moment monitoring parameters of each joint of the double arms based on the initial bearing moment takes the maximum deviation between the actual monitoring moment value of the joint at the near centroid side and the preset initial bearing moment reference value as the moment peak value difference of the joint at the near centroid side, and comprises the following steps: Setting moment monitoring parameters of all joints of the double arms according to an initial bearing moment value of an arm near the center of mass, obtaining a current joint angle and a corresponding driving current, and obtaining an actual output moment value of each joint by conversion according to a linear relation between motor torque and current; And continuously monitoring the actual output moment value by adopting fixed time windows, calculating real-time differences between the moment values of all joints at the near centroid side and the initial bearing moment reference value in each time window, judging the deformation development trend of the contact point by the variation of the differences between adjacent windows, and extracting the maximum value from the continuously monitored difference sequence as moment peak value difference.
4. A pre-determined distance and pose planning method for a humanoid robot according to claim 3, wherein said extracting a maximum value from a continuously monitored difference sequence as a moment peak difference further comprises: Recording corresponding contact pressure distribution data when the peak value is reached, judging whether the contact point near the mass center is close to the critical deformation degree or not through comparison of the moment peak value difference and a preset deformation safety threshold value, if the moment peak value difference exceeds the deformation safety threshold value, identifying a concentrated area with pressure exceeding the preset pressure threshold value from the contact pressure distribution data, calculating the ratio of the pressure difference between adjacent measuring points in the area to the distance to obtain a stress gradient, and evaluating the residual bearing capacity of the contact point according to the ratio of the stress gradient to the initial elastic modulus of the material to obtain the deformation approaching degree reflecting the contact stability near the mass center.
5. The method for planning a pre-determined distance and a gesture before grabbing a humanoid robot according to claim 1, wherein the adjusting the moment distribution according to the moment peak difference to reduce the near-centroid side vertical support moment and increase the far-centroid side compensation moment, determining the target moment values of each joint, and generating a joint moment distribution scheme includes: Determining a value to be reduced of the moment on the near centroid side from a preset hierarchical adjustment rule according to the moment peak value difference, and calculating to obtain a vertical supporting moment value reduced on the near centroid side and a compensating moment value increased on the far centroid side, so that the total supporting moment of the object is kept unchanged; the vertical supporting moment value reduced at the near centroid side and the compensating moment value increased at the far centroid side are combined with the current joint angle configuration of the double arms, and driving moment required to be output by each of the shoulder joint, the elbow joint and the wrist joint is calculated reversely from moment required by the tail end through moment transmission relation in robot kinematics, so that target moment values of all joints are obtained; And comparing the target moment values of all the joints with a preset maximum bearing moment upper limit of the joints, if the target moment of any joint at the near centroid side exceeds the maximum bearing moment upper limit, reducing moment reduction at the near centroid side according to the exceeding proportion, and redistributing the moments at two sides until the target moment of all the joints is within a safety range.
6. The method for planning the pre-judgment distance and the gesture before grabbing of the humanoid robot according to claim 1, further comprising the steps of executing the joint moment distribution scheme, verifying the contact state of a contact point at the side of a near centroid, comparing the local deformation quantity at the side of the near centroid with a preset slip instability limit value, and outputting a moment peak value control result comprising the current moment balance state of the double arms.
7. The method for planning pre-determined distance and pose before grabbing of humanoid robot according to claim 6, wherein said executing the joint moment distribution scheme and verifying the contact state of the near-centroid side contact point comprises: The joint motor driver is used for applying the adjusted target moment value, real-time pressure distribution data of the contact point of the near centroid side is collected from the pressure sensor array, and the local deformation quantity is calculated according to the relation between the pressure change of the contact area and the elastic modulus of the material; And calculating the difference value of the local deformation quantity between the adjacent measuring points, comparing the difference value with a preset slip instability limit value, judging the contact stability, marking the situation that the slip risk exists if the maximum value in the local deformation quantity exceeds the preset proportion of the preset slip instability limit value, and marking the situation that the slip risk exists if the maximum value in the local deformation quantity does not exceed the preset proportion of the slip instability limit value, and marking the situation that the slip risk is in a stable state.
8. The method for planning pre-determined distance and gesture before grabbing of humanoid robot according to claim 7, wherein the output includes a torque peak control result of a current torque balance state of the two arms, and the method comprises: Based on the judging result of the stable state or the slip risk, calculating a deviation root mean square value as a moment balance index by combining the deviation of the current actual moment value and the target moment value of each joint of the double arms, integrating the moment balance index, the deformation value and the slip risk judging result, and outputting a moment peak value control result containing the current moment balance state of the double arms of the humanoid robot.
9. The method for planning pre-determined distance and pose before grabbing of humanoid robot according to claim 1, wherein each joint comprises a shoulder joint, an elbow joint and a wrist joint.
10. The utility model provides a human robot prejudges distance and gesture planning device before snatching which characterized in that, the device includes: The data acquisition and initial moment determination module is used for acquiring initial grabbing data of an object contact point, acquiring the longitudinal offset distance of the mass center of the object and the elastic modulus of the surface of the side of the near mass center, and determining the initial bearing moment of the arm of the side of the near mass center according to the longitudinal offset distance of the mass center and the elastic modulus of the surface of the side of the near mass center; The moment monitoring and peak value difference calculation module is used for setting moment monitoring parameters of all joints of the double arms based on the initial bearing moment and monitoring, and taking the maximum deviation between the actual monitoring moment value of the near-centroid side joint and a preset initial bearing moment reference value as the moment peak value difference of the near-centroid side joint; And the moment distribution adjusting module is used for adjusting moment distribution according to the moment peak value difference so as to reduce the near-centroid side vertical supporting moment and increase the far-centroid side compensating moment, determining the target moment value of each joint and generating a joint moment distribution scheme.

Description

Prejudgment distance and gesture planning method and device before grabbing of humanoid robot Technical Field The invention relates to the technical field of information, in particular to a method and a device for planning a prejudgment distance and a gesture before grabbing a humanoid robot. Background Humanoid robotics are gradually entering a handling scenario where complex objects need to be handled, wherein the cooperation of the arms to complete the gripping and handling of long objects is one of the important directions that push their practical use. The task has key significance in the fields of shaft part handling on an industrial assembly line, irregular pipe sorting in a logistics warehouse, auxiliary traveling long rods used by the old in the nursing scene of the aged, auxiliary elongated steel bar or batten handling on a construction site and the like, and the task directly determines the operation reliability and the safety of the robot in the unstructured and non-uniform quality distribution environments. Currently most two-arm collaborative strategies typically rely simply on the geometric center of the object or through pre-measured centroid positions for static allocation when determining the gripping position, pose planning, and the proportion of load that each arm bears. This distribution assumes that the overall stiffness of the object is uniform and that the forces on the arms can be divided in linear proportion to the centroid position. However, in reality, a large number of elongated objects often have significant mass uneven distribution, such as a composite tube with unevenly filled inside, a metal rod with a heavy fitting welded at one end, a wood material with gradually changing density along the length direction, or some special-shaped logistics packaging rods, which all cause the mass center to deviate significantly from the geometric center. When the mass center is obviously deviated to one side, the arm close to the mass center needs to bear larger vertical supporting force, so that the lateral elbow joint bears obviously higher buckling moment, and the arm far from the mass center needs to maintain the whole moment balance by greatly adjusting the angle of the shoulder joint and even the waist gesture. in actual handling, the object is rarely completely rigid, especially when the end near the centroid is significantly lower in local compressive stiffness than the end away from the centroid because of the softer material itself, thinner wall thickness, honeycomb structure inside or foam filling. In this case, once the moment applied by the near-centroid side arm exceeds the range that can be tolerated by the local material stiffness, compression deformation or even a minute fold is first generated near the grip point. The local deformation can directly change the normal and tangential relation of the originally planned contact surface, the grabbing point originally designed to be in surface contact can be degenerated into point contact or line contact, the friction force is rapidly reduced, and the tiny slippage of the grabbing point is easily caused. When the sliding is started, the moment balance relation between the two arms, which is originally calculated elaborately, is destroyed rapidly, the moment of the near arm, which is originally increased specially for compensating the centroid bias, is instead changed into a push hand for accelerating local deformation, the deformation degree is increased, the holding stability is further weakened, the far arm is forced to quickly make gesture compensation to prevent the whole object from tilting or falling, and the whole system is involved in a vicious cycle that the moment is severely oscillated and the gestures of the two arms are continuously adjusted back and forth. Especially when the length of the object is longer, the surface rigidity presents obvious gradient change along the axial direction, for example, one end is connected with a long rod wrapped by soft rubber at the other end, or a coiled material packaging rod with extremely large internal and external density difference is common in logistics, disturbance caused by small deformation at the side near the center of mass can be quickly transmitted along the length direction of the object, so that macroscopic bending or torsion is generated at the far end, further, the originally pursued symmetrical collaborative gesture of the double arms is thoroughly collapsed, the moment of a joint at one side is continuously overloaded and warned, and the other side cannot provide enough support to have an extremely contradictory situation of uncontrolled loosening. How to accurately identify the deformation trend of a low-rigidity area caused by the increase of stress under the conditions that the centroid bias is obvious and the rigidity of the object surface is unevenly distributed along the length direction, and accordingly coordinate the respective borne moment of th