Automobile bumper grabbing displacement system and method

Abstract

The application provides a car bumper grabbing displacement system and method. The force moment distribution characteristics of a mechanical hand at a selected grabbing point in a car bumper displacement trajectory are extracted from the touch force feedback information of the selected grabbing point in the car bumper displacement trajectory, and then the inertia deformation compensation is performed on the force moment distribution characteristics to obtain the displacement load moment of the selected grabbing point at the current displacement point in the displacement trajectory. When the displacement load moment is greater than the allowable moment threshold of the selected grabbing point in the car bumper, the displacement speed of the mechanical hand at the current displacement point in the displacement trajectory is obtained, then the safety deceleration of the displacement speed is matched, and the moment overrun value of the selected grabbing point in the car bumper at the current displacement point is determined. The displacement speed of the mechanical hand at the current displacement point is attenuated and adjusted by using the moment overrun value and the safety deceleration. Based on the above scheme, the adaptive speed adjustment of real-time force feedback in the car bumper grabbing displacement can be realized.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of programmed mechanical hand control, in particular to an automobile bumper grabbing and displacement system and method. BACKGROUND

[0002] The automobile bumper is a rigid plastic or composite material component installed at the front and rear ends of the vehicle, and is an important safety and decorative part of the vehicle body. Its main function is to absorb energy and reduce vehicle body damage during low-speed collision, and to protect pedestrians. Modern bumpers are painted in the same color as the vehicle body, and are integrated with fog lamps, radar sensors, etc., and have both aesthetic and intelligent functions.

[0003] In the automobile automatic assembly line, the prior art simplifies the large injection molded bumper into a rigid body for robot motion trajectory planning, ignoring its inherent flexible characteristics as a large size thin-walled component. When the mechanical hand grabs the bumper and performs high-speed displacement, the workpiece will be significantly elastically deformed due to its own gravity and inertial acceleration generated by motion start-stop and turning, so that the actual shape of the bumper deviates from the preset rigid model, resulting in unexpected alternating stress inside the bumper. When rotating quickly or stopping suddenly, the stress will concentrate in the local weak area, which may not only cause invisible damage such as micro-cracks or plastic deformation of the internal structure of the buckle seat, affecting the long-term reliability of the product, but also cause assembly stress in the final installation station, resulting in uneven gap and unevenness, abnormal noise, and even quality problems such as early failure of the buckle. Therefore, how to realize adaptive speed regulation of real-time force feedback in automobile bumper grabbing and displacement has become a difficult problem in the industry. SUMMARY

[0004] The application provides an automobile bumper grabbing and displacement system and method, which can realize adaptive speed regulation of real-time force feedback in automobile bumper grabbing and displacement.

[0005] In a first aspect, the application provides an automobile bumper grabbing and displacement method, comprising:

[0006] Initializing the selected grabbing point of the mechanical hand to the automobile bumper, and monitoring the touch force feedback information of the selected grabbing point of the automobile bumper in the displacement motion;

[0007] Generating a displacement trajectory of the automobile bumper in the displacement motion through the spatial pose of the selected grabbing point and the target placement point of the automobile bumper, extracting the torque distribution characteristics of the selected grabbing point of the mechanical hand in the displacement motion according to the displacement trajectory from the touch force feedback information, and then performing inertia deformation compensation on the torque distribution characteristics to obtain the displacement load torque of the selected grabbing point at the current displacement point in the displacement trajectory;

[0008] When the variable position load torque is greater than the allowable torque threshold of the selected grabbing point in the automobile bumper, a variable position speed of the manipulator at a current variable position point in the variable position trajectory is obtained, and then a safety deceleration matching the variable position speed is matched, and a torque overrun value of the selected grabbing point in the automobile bumper at the current variable position point is determined.

[0009] The variable position speed of the manipulator at the current variable position point is attenuated and adjusted using the torque overrun value and the safety deceleration.

[0010] In some embodiments, generating the variable position trajectory of the automobile bumper in the variable position motion by the spatial pose of the selected grabbing point and the target placement point of the automobile bumper specifically includes:

[0011] initializing a static variable position path between the spatial pose of the selected grabbing point and the target placement point of the automobile bumper;

[0012] performing static collision avoidance on the static variable position path to obtain the variable position trajectory of the automobile bumper in the variable position motion.

[0013] In some embodiments, extracting the torque distribution feature of the selected grabbing point when the manipulator moves according to the variable position trajectory specifically includes:

[0014] obtaining torque information of the selected grabbing point in the sensor coordinate system from the touch force feedback information;

[0015] converting the torque information from the sensor coordinate system to the manipulator end tool coordinate system to obtain an axial torque matrix of the manipulator in the manipulator end tool coordinate system;

[0016] extracting a plurality of axial torque values in the axial torque matrix to obtain the torque distribution feature of the selected grabbing point when the manipulator moves according to the variable position trajectory.

[0017] In some embodiments, compensating the torque distribution feature for inertial deformation to obtain a variable position load torque of the selected grabbing point at a current variable position point in the variable position trajectory specifically includes:

[0018] obtaining a static torque of the gravity of the automobile bumper in the manipulator end tool coordinate system;

[0019] determining an inertial torque of the selected grabbing point at the current variable position point based on an angular acceleration and an inertial tensor of the current variable position point in the variable position trajectory;

[0020] compensating the torque distribution feature using the static torque and the inertial torque to obtain the variable position load torque of the selected grabbing point at the current variable position point in the variable position trajectory.

[0021] In some embodiments, matching the safety deceleration of the variable displacement speed specifically comprises:

[0022] inquiring the maximum safety deceleration of the variable displacement speed;

[0023] setting an inertial safety coefficient of the selected gripping point based on the model of the manipulator-based device;

[0024] determining the safety deceleration of the variable displacement speed by the maximum safety deceleration and the inertial safety coefficient.

[0025] In some embodiments, determining the torque overrun value of the selected gripping point in the current variable displacement point in the automobile bumper specifically comprises:

[0026] obtaining the allowable torque threshold of the selected gripping point in the automobile bumper and the variable displacement load torque of the current variable displacement point;

[0027] determining the torque overrun value of the selected gripping point in the current variable displacement point in the automobile bumper by the allowable torque threshold and the variable displacement load torque.

[0028] In some embodiments, using the torque overrun value and the safety deceleration to perform decaying adjustment on the variable displacement speed of the manipulator at the current variable displacement point specifically comprises:

[0029] calculating the variable displacement speed adjustment amount of the manipulator at the current variable displacement point based on the torque overrun value;

[0030] determining the decaying gradient and decaying time of the variable displacement speed of the manipulator at the current variable displacement point by the safety deceleration and the variable displacement speed adjustment amount;

[0031] adjusting the variable displacement speed of the manipulator at the current variable displacement point using the decaying gradient and the decaying time.

[0032] In a second aspect, the present application provides an automobile bumper gripping and variable displacement system, comprising:

[0033] a monitoring module for initializing the selected gripping point of the automobile bumper by the manipulator, and monitoring the touch force feedback information of the selected gripping point in the variable displacement motion of the automobile bumper;

[0034] a processing module for generating the variable displacement trajectory of the automobile bumper in the variable displacement motion by the spatial pose of the selected gripping point and the target placement point of the automobile bumper, extracting the torque distribution characteristics of the selected gripping point when the manipulator performs the variable displacement motion according to the variable displacement trajectory from the touch force feedback information, and then performing inertial deformation compensation on the torque distribution characteristics to obtain the variable displacement load torque of the selected gripping point at the current variable displacement point in the variable displacement trajectory;

[0035] The processing module is further configured to, when the variable position load torque is greater than the allowable torque threshold of the selected gripping point in the automobile bumper, acquire a variable position speed of the manipulator at a current variable position point in the variable position trajectory, then match a safe deceleration of the variable position speed, and determine a torque overrun value of the selected gripping point in the automobile bumper at the current variable position point.

[0036] The execution module is configured to perform attenuation adjustment on the variable position speed of the manipulator at the current variable position point using the torque overrun value and the safe deceleration.

[0037] In a third aspect, the present application provides a computer device, which comprises a memory and a processor, the memory is configured to store a computer program, and the processor is configured to call and run the computer program from the memory, so that the computer device executes the automobile bumper gripping and variable position method described above.

[0038] In a fourth aspect, the present application provides a computer readable storage medium, which stores instructions or codes, when the instructions or codes are run on a computer, the computer executes the automobile bumper gripping and variable position method described above.

[0039] The technical scheme provided by the embodiments of the present application has the following beneficial effects:

[0040] In the automobile bumper gripping and variable position system and method provided by the present application, a selected gripping point of the automobile bumper by the manipulator is initialized, and touch force feedback information of the selected gripping point in variable position movement of the automobile bumper is monitored; a variable position trajectory of the automobile bumper in the variable position movement is generated through the spatial pose of the selected gripping point and a target placement point of the automobile bumper, a torque distribution feature of the selected gripping point when the manipulator moves according to the variable position trajectory is extracted from the touch force feedback information, then the torque distribution feature is compensated for inertia deformation to obtain a variable position load torque of the selected gripping point at a current variable position point in the variable position trajectory; when the variable position load torque is greater than an allowable torque threshold of the selected gripping point in the automobile bumper, a variable position speed of the manipulator at the current variable position point in the variable position trajectory is acquired, then a safe deceleration of the variable position speed is matched, and a torque overrun value of the selected gripping point in the automobile bumper at the current variable position point is determined; and the variable position speed of the manipulator at the current variable position point is attenuated and adjusted using the torque overrun value and the safe deceleration.

[0041] Therefore, in the present application, the torque overrun value and the safety deceleration are used to attenuate and adjust the displacement speed of the manipulator at the current displacement point; first, the displacement load torque is determined to obtain the net load reflecting the real external disturbance, thereby providing accurate perception basis for intelligent decision-making; determining the displacement load torque can realize the key data processing link of extracting effective load characteristics from mixed signals, the displacement load torque reflects the unexpected external load borne by the manipulator and the bumper system, which is composed of the elastic deformation stress of the workpiece and the external contact force, determining the displacement load torque converts the abstract sensor readings into an accurate physical quantity representing the real-time safety state of the system, thereby providing a high-confidence input reference for subsequent control decision-making, avoiding false triggering or response lag caused by signal mixing, and laying the accuracy and reliability of the perception layer of the entire adaptive control system; then, the torque overrun value is determined to obtain the quantitative evaluation of the load state deviating from the safety boundary, thereby realizing proportional control mapping based on the risk level; the torque overrun value is a decision conversion link connecting state perception and execution control, which realizes quantitative evaluation of the current load state deviating from the safe operation range, converts qualitative safety judgment into a continuous quantitative risk level index, and the control system can calculate the required deceleration command in proportion according to the size of the torque overrun value, rather than executing a simple Boolean emergency stop logic, ensuring that the control output matches the real-time risk level, realizing optimal control effect that can effectively suppress load overrun and maximize motion smoothness, and solving the contradiction between safety and smoothness in traditional control; in summary, based on the above scheme, real-time force feedback adaptive speed regulation in automobile bumper grabbing displacement can be realized. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0043] Figure 1 is an exemplary flowchart of the automobile bumper grabbing displacement method according to some embodiments of the present application;

[0044] Figure 2 is a flowchart of determining the safety deceleration according to some embodiments of the present application;

[0045] Figure 3 is a structural schematic diagram of the automobile bumper grabbing displacement system according to some embodiments of the present application;

[0046] Figure 4is a structural schematic diagram of a computer device for implementing a method for grabbing and displacing an automobile bumper according to some embodiments of the present application. DETAILED DESCRIPTION

[0047] In order to better understand the technical solutions of the present application, the technical solutions of the present application will be described in detail below in combination with the accompanying drawings and specific embodiments.

[0048] Reference Figure 1 The figure is an exemplary flowchart of a method for grabbing and displacing an automobile bumper according to some embodiments of the present application, which mainly includes the following steps:

[0049] In step 101, the selected grabbing point of the robot to the automobile bumper is initialized, and the touch force feedback information of the selected grabbing point of the automobile bumper in the displacement motion is monitored.

[0050] It should be noted that in the present application, the device model refers to a number code uniquely identifying the type of automobile bumper, which is associated with the physical attribute parameters of the three-dimensional geometric dimensions, mass, mass center position, inertia tensor, optimal grabbing area position and allowable torque threshold of the bumper; the selected grabbing point is a set of spatial coordinates of one or more grabbing positions; the touch force feedback information is a set of data of three-direction force components and three-direction torque components between the end effector of the robot and the robot arm.

[0051] In a specific implementation, first, the initialization of the selected gripping point of the robot for the automobile bumper can be achieved in the following manner: the central control system receives the production instruction issued by the upper computer, which contains the device model of the automobile bumper to be gripped, and then retrieves the corresponding gripping parameters from the pre-generated gripping strategy database according to the device model; the gripping parameters include the three-dimensional space coordinates and attitude angle of the selected gripping point in the robot base coordinate system, as well as the activation mode of the vacuum cup array; after successful retrieval, the central control system sends a motion instruction to the robot controller to drive the robot arm to move the end effector to the initial preparation position defined by the selected gripping point, and complete all parameter configurations before gripping, thereby completing the initialization of the selected gripping point of the robot for the automobile bumper; then, the monitoring of the touch force feedback information of the selected gripping point of the automobile bumper during the displacement movement can be achieved in the following manner: during the entire displacement movement of the robot along the planned trajectory, the six-axis force / torque sensor continuously collects the original force and torque signals at a fixed sampling frequency; after the force and torque signals are processed by the signal conditioning circuit for noise reduction and filtering, they are transmitted in real time to the central control system through the field bus; the data processing module in the central control system receives the force and torque signals and converts them into touch force feedback information data stream expressed in the robot end tool coordinate system, which can be used for logical judgment, as the touch force feedback information of the selected gripping point of the automobile bumper during the displacement movement.

[0052] In step 102, a displacement trajectory of the automobile bumper during the displacement movement is generated based on the spatial pose of the selected gripping point and the target placement point of the automobile bumper, the moment distribution characteristics of the selected gripping point of the robot during the displacement movement according to the displacement trajectory are extracted from the touch force feedback information, and then the inertia deformation compensation is performed on the moment distribution characteristics to obtain the displacement load moment of the selected gripping point at the current displacement point in the displacement trajectory.

[0053] In some embodiments, the generation of the displacement trajectory of the automobile bumper during the displacement movement based on the spatial pose of the selected gripping point and the target placement point of the automobile bumper can be achieved in the following steps:

[0054] Initialize the static displacement path between the spatial pose of the selected gripping point and the target placement point of the automobile bumper;

[0055] Perform static collision avoidance on the static displacement path to obtain the displacement trajectory of the automobile bumper during the displacement movement.

[0056] It should be noted that in the present application, the variable displacement trajectory represents the complete motion path directly executed by the manipulator controller; the spatial pose of the selected grasping point represents the spatial position and attitude of the manipulator end at the initial moment of grasping; and the static variable displacement path is the theoretical spatial motion route of the manipulator from the starting point to the target point.

[0057] In a specific implementation, first, the static variable displacement path between the spatial pose of the selected grasping point and the target placement point of the automobile bumper can be implemented in the following manner: the path planning module reads the two pose nodes of the spatial pose of the selected grasping point and the target placement point of the automobile bumper from the system memory; and a quintic polynomial interpolation algorithm is used to perform interpolation calculation between the two pose nodes to generate a series of dense and continuous spatial path points; all the spatial path points are connected together to form a smooth and continuous motion route in the joint space as the static variable displacement path; then, the static variable displacement path is subjected to static collision avoidance to obtain the variable displacement trajectory of the automobile bumper in the variable displacement motion, which can be implemented in the following manner: the collision detection module performs fast distance calculation and interference judgment on each spatial path point on the static variable displacement path and the pre-imported three-dimensional model database describing the accurate geometric shapes of all devices in the entire work unit, for example, the fast distance calculation and interference judgment based on the bounding box algorithm can be used; once it is detected that the minimum distance between the manipulator or the automobile bumper model grasped by the manipulator on the spatial path point and any other model in the environment is less than a pre-set safety threshold, it is determined that the spatial path point is a potential collision point; new obstacle avoidance path points are introduced near each potential collision point or the attitude of the manipulator end is adjusted, so that the original static variable displacement path is locally modified and bypassed, for example, the path optimization algorithm based on the artificial potential field method can be used for collision avoidance planning of the potential collision points; after repeated iteration detection and collision avoidance planning, a theoretically collision-free and smooth safety path is generated as the variable displacement trajectory, and the variable displacement trajectory is output to the manipulator motion controller for execution.

[0058] In some embodiments, extracting the torque distribution characteristics of the selected grasping point when the manipulator moves according to the variable displacement trajectory can be implemented in the following steps:

[0059] Obtaining torque information of the selected grasping point in the sensor coordinate system from the touch force feedback information;

[0060] Converting the torque information from the sensor coordinate system to the manipulator end tool coordinate system to obtain an axial torque matrix of the manipulator in the manipulator end tool coordinate system;

[0061] Extracting a plurality of axial torque values in the axial torque matrix to obtain the torque distribution characteristics of the selected grasping point when the manipulator moves according to the variable displacement trajectory.

[0062] It should be noted that in the present application, the torque distribution feature is used to describe the mathematical vector feature of the external load torque size and direction on the end of the manipulator; the torque information is the three torque component data directly measured and output by the six-dimensional force / torque sensor in the reference coordinate system with its own geometric center as the origin and with its sensitive axis direction as the coordinate axis; the axial torque matrix is the force / torque vector under the tool coordinate system of the end of the manipulator.

[0063] In specific implementation, firstly, the torque information of the selected gripping point in the sensor coordinate system can be obtained from the touch force feedback information in the following manner: the data acquisition unit converts and calibrates decoupling calculation on the force and torque signals in the touch force feedback information according to the pre-calibrated sensor sensitivity coefficient and zero point bias parameter, to obtain three torque component values, for example: a static algorithm based on least squares method can be used for conversion and calibration decoupling calculation; the set of three torque component values is taken as the torque information of the selected gripping point in the sensor coordinate system; then, the torque information is converted from the sensor coordinate system to the tool coordinate system of the end of the manipulator, to obtain the axial torque matrix of the manipulator in the tool coordinate system of the end of the manipulator, which can be realized in the following manner: the coordinate transformation unit calls the rotation transformation relationship from the sensor coordinate system to the tool coordinate system of the end of the manipulator, which is measured by the hand-eye calibration program in advance, and the rotation transformation relationship is a rotation matrix, which is a three-by-three orthogonal matrix used to represent the relative rotation transformation relationship between the sensor coordinate system and the tool coordinate system of the end of the manipulator, and the coordinate transformation unit performs matrix multiplication operation on the torque vector in the sensor coordinate system and the axial torque matrix, to calculate the equivalent torque vector expressed in the tool coordinate system of the end of the manipulator as the axial torque matrix of the manipulator in the tool coordinate system of the end of the manipulator; finally, the multiple axial torque values in the axial torque matrix are extracted, and then the torque distribution feature of the selected gripping point when the manipulator moves according to the displacement trajectory can be obtained in the following manner: the feature extraction unit directly reads the three scalar components of the torque vector obtained after coordinate system conversion, and the three scalar components respectively represent the torque size along the X-axis, Y-axis and Z-axis directions of the tool coordinate system of the end of the manipulator, i.e. multiple axial torque values; the three axial torque values are sequentially combined into a three-dimensional column vector, which is the torque distribution feature at the current time for representing the load state of the end of the manipulator.

[0064] In some embodiments, the torque distribution feature is compensated for inertia deformation to obtain the displacement load torque of the selected gripping point at the current displacement point in the displacement trajectory, which can be realized in the following steps:

[0065] The static torque of the gravity of the automobile bumper in the tool coordinate system of the end of the manipulator is obtained;

[0066] determining the inertia moment of the selected gripping point at the current displacement point based on the angular acceleration of the current displacement point in the displacement trajectory and the inertia tensor;

[0067] compensating the moment distribution feature using the static moment and the inertia moment to obtain the displacement load moment of the selected gripping point at the current displacement point in the displacement trajectory.

[0068] It should be noted that in the present application, the displacement load moment is the external load caused by the flexible deformation of the automobile bumper or the contact collision with the external object; the static moment is the moment component generated by the robot end tool coordinate system when the robot is in a static state; the angular acceleration is the angular acceleration component of the robot end tool coordinate system rotating around its three coordinate axes in the displacement trajectory; the inertia tensor is a three-by-three symmetric matrix describing the spatial distribution of the mass of the automobile bumper relative to the selected gripping point; and the inertia moment is the moment generated by the automobile bumper to resist the change of the motion state due to its own inertia.

[0069] In specific implementation, first, the static moment of the automobile bumper gravity in the robot end tool coordinate system can be realized in the following manner: querying the real-time posture of the current robot at real-time motion from the mapping relationship table between the gravity moment and the robot posture to obtain the query gravity moment corresponding to the real-time posture as the static moment of the automobile bumper gravity in the robot end tool coordinate system; then, the inertia moment of the selected gripping point at the current displacement point in the displacement trajectory can be realized in the following manner: the kinematics calculation module calculates the angular velocity vector of the robot end tool coordinate system at the current time through the differential kinematics model of the robot according to the angular acceleration and joint angular velocity of the robot; and then the angular velocity vector is subjected to numerical differentiation to obtain the angular acceleration vector of the current displacement point; at the same time, the inertia tensor matrix of the equipment model of the automobile bumper relative to the selected gripping point is screened from the pre-stored product parameter database, and the inertia tensor matrix is subjected to matrix multiplication operation with the angular acceleration vector, and the calculation result is taken as the inertia moment of the selected gripping point at the current displacement point; finally, the displacement load moment of the selected gripping point at the current displacement point in the displacement trajectory can be realized in the following manner: performing vector subtraction operation, subtracting the static moment vector and the inertia moment vector from the moment distribution feature vector in sequence, and the result vector obtained after subtraction is taken as the displacement load moment of the selected gripping point at the current displacement point in the displacement trajectory.

[0070] In step 103, when the variable position load torque is greater than the allowable torque threshold of the selected gripping point in the automobile bumper, the variable position speed of the manipulator at the current variable position point in the variable position trajectory is obtained, and then the safety deceleration matching the variable position speed is matched, and the torque overrun value of the selected gripping point in the automobile bumper at the current variable position point is determined.

[0071] It should be noted that in the present application, when the variable position load torque is greater than the allowable torque threshold of the selected gripping point in the automobile bumper, it indicates that the load borne by the end of the manipulator has exceeded the safe working range determined by the material characteristics, structural strength and gripping reliability of the bumper, and the overrun state may be caused by accidental collision of the bumper with the external environment or excessive flexible deformation of the bumper itself; in order to prevent the load torque from further increasing to cause permanent damage to the bumper, gripping failure and falling off, or damage to the manipulator body, the motion of the manipulator must be intervened immediately, the inertia force and impact force generated by the motion are reduced by reducing the variable position speed, so that the variable position load torque is forced to decrease and return to below the allowable torque threshold, thereby ensuring the operation safety and the integrity of the workpiece.

[0072] In some embodiments, the safety deceleration matching the variable position speed is determined with reference to Figure 2 The figure is a flowchart for determining the safety deceleration in some embodiments of the present application, and the safety deceleration in the present embodiment can be realized by the following steps:

[0073] In step 1031, the maximum safety deceleration of the variable position speed is queried;

[0074] In step 1032, the inertia safety factor of the selected gripping point is set based on the equipment model of the manipulator;

[0075] In step 1033, the safety deceleration of the variable position speed is determined by the maximum safety deceleration and the inertia safety factor.

[0076] It should be noted that in the present application, the safety deceleration is a deceleration value for attenuating and adjusting the current variable position speed of the manipulator; the maximum safety deceleration is an upper limit of the deceleration allowed to be applied to ensure that the automobile bumper does not slip out of the gripper or is not structurally damaged under the current motion state of the manipulator; and the inertia safety factor is a scaling factor for compensating for the error between the theoretical model and the actual situation and the unpredictable external disturbance.

[0077] In a specific implementation, first, the maximum safe deceleration of the displacement speed can be achieved by the following method: the control system uses the current real-time collected displacement speed as an index to query the deceleration query table pre-stored in the safety parameter database, and queries the maximum safe deceleration of the displacement speed from the deceleration query table; then, the inertia safety factor of the selected gripping point based on the equipment model of the manipulator can be achieved by the following method: the control system calls the inertia safety factor pre-set for the manipulator of the equipment model and its matching gripper from the safety parameter database according to the equipment model of the manipulator; the specific value of the inertia safety factor is determined based on the historical operation data of the equipment of the equipment model, the gripping reliability test results and engineering experience, and the value of the inertia safety factor is always less than one, and is used to reduce the theoretical calculation value to provide a safety margin; finally, the safe deceleration of the displacement speed can be achieved by the following method: the product of the maximum safe deceleration and the inertia safety factor is taken as the safe deceleration of the displacement speed.

[0078] In some embodiments, determining the torque overrun value of the selected gripping point in the automobile bumper at the current displacement point can be achieved by the following steps:

[0079] Obtaining the allowable torque threshold of the selected gripping point in the automobile bumper and the displacement load torque of the current displacement point;

[0080] Determining the torque overrun value of the selected gripping point in the automobile bumper at the current displacement point by the allowable torque threshold and the displacement load torque.

[0081] It should be noted that in this application, the torque overrun value is a quantitative value reflecting the degree of current load torque exceeding the safe range; in a specific implementation, first, the allowable torque threshold of the selected gripping point in the automobile bumper and the displacement load torque of the current displacement point are obtained; then, the torque overrun value of the selected gripping point in the automobile bumper at the current displacement point can be achieved by the following method: the difference between the allowable torque threshold and the displacement load torque is taken as the torque overrun value of the selected gripping point in the automobile bumper at the current displacement point.

[0082] In step 104, the displacement speed of the manipulator at the current displacement point is adjusted using the torque overrun value and the safe deceleration.

[0083] In some embodiments, the displacement speed of the manipulator at the current displacement point can be adjusted using the torque overrun value and the safe deceleration by the following steps:

[0084] Calculating the displacement speed adjustment amount of the manipulator at the current displacement point based on the torque overrun value;

[0085] determining a decay gradient and a decay time of the displacement speed of the manipulator at the current displacement point according to the safety deceleration and the displacement speed adjustment amount;

[0086] adjusting the displacement speed of the manipulator at the current displacement point using the decay gradient and the decay time.

[0087] It should be noted that in the present application, the displacement speed adjustment amount is an instruction change value for reducing the current motion speed of the manipulator; the decay gradient is a physical quantity for actually controlling the motion state of the manipulator, indicating the displacement speed reduction amount per unit time; and the decay time is the total time required to complete the current speed adjustment.

[0088] In a specific implementation, first, the displacement speed adjustment amount of the manipulator at the current displacement point based on the torque overrun value can be implemented in the following manner: a control algorithm unit multiplies the received torque overrun value by a negative proportional coefficient, which determines the response sensitivity of the system to the torque overrun, and the result of the multiplication operation is an ideal displacement speed adjustment amount of the manipulator at the current displacement point. The displacement speed adjustment amount is a negative speed value, and the numerical value of the displacement speed adjustment amount is directly proportional to the degree of torque overrun. The more serious the overrun, the greater the displacement speed adjustment amount. Then, the decay gradient and the decay time of the displacement speed of the manipulator at the current displacement point according to the safety deceleration and the displacement speed adjustment amount can be implemented in the following manner: the safety deceleration is taken as the decay gradient of the displacement speed of the manipulator at the current displacement point, and the ratio of the displacement speed adjustment amount to the decay gradient is taken as the decay time of the displacement speed of the manipulator at the current displacement point. Finally, adjusting the displacement speed of the manipulator at the current displacement point using the decay gradient and the decay time can be implemented in the following manner: a motion controller generates a speed planning curve that linearly decreases from the current speed to the target speed, taking the current displacement speed as the initial value, the decay gradient as the slope of the speed change, and the decay time as the adjustment duration. The motion controller sends a speed instruction to the servo driver of the manipulator in real time according to the speed planning curve, thereby smoothly and controllably reducing the current displacement speed of the manipulator to a safe level.

[0089] In addition, another aspect of the present application, in some embodiments, the present application provides a car bumper grabbing displacement system, referring to Figure 3 the figure is a structural schematic diagram of a car bumper grabbing displacement system according to some embodiments of the present application, which includes a monitoring module 201, a processing module 202 and an execution module 203, which are described as follows:

[0090] The monitoring module 201 is mainly used for initializing the selected gripping point of the mechanical arm to the automobile bumper, and monitoring the touch force feedback information of the selected gripping point in the position change motion of the automobile bumper.

[0091] The processing module 202 is used for generating a position change trajectory of the automobile bumper in the position change motion by the spatial pose of the selected gripping point and a target placement point of the automobile bumper, extracting a torque distribution feature of the selected gripping point in the position change motion according to the position change trajectory from the touch force feedback information, and then performing inertia deformation compensation on the torque distribution feature to obtain a position change load torque of the selected gripping point at a current position change point in the position change trajectory.

[0092] It should be noted that the processing module 202 is also used for obtaining a position change speed of the mechanical arm at the current position change point in the position change trajectory when the position change load torque is greater than a permissible torque threshold of the selected gripping point in the automobile bumper, matching a safe deceleration of the position change speed, and determining a torque overrun value of the selected gripping point in the automobile bumper at the current position change point.

[0093] The execution module 203 is mainly used for attenuating and adjusting the position change speed of the mechanical arm at the current position change point by using the torque overrun value and the safe deceleration.

[0094] The above describes the examples of the automobile bumper gripping and position changing system and method provided by the embodiments of the present application in detail. It can be understood that the corresponding device contains the hardware structure and / or software module corresponding to the execution of each function in order to realize the above functions. Those skilled in the art should easily realize that the units and algorithm steps of each example described in combination with the embodiments disclosed in the present application can be realized in the form of hardware or a combination of hardware and computer software. Whether a certain function is realized in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0095] In some embodiments, the present application also provides a computer device, which comprises a memory and a processor, the memory is used for storing a computer program, and the processor is used for calling and running the computer program from the memory, so that the computer device executes the automobile bumper gripping and position changing method described above.

[0096] In some embodiments, with reference to Figure 4, the dashed line in the figure indicates that the unit or the module is optional, and the figure is a structural schematic diagram of a computer device for implementing the method for grabbing and displacing the automobile bumper according to the embodiments of the present application. The method for grabbing and displacing the automobile bumper described in the above embodiments can be implemented by the computer device shown in the figure, which includes at least one processor 301, a memory 302, and at least one communication unit 305, and the computer device can be a terminal device or a server or a chip. Figure 4 The processor 301 can be a general-purpose processor or a special-purpose processor. For example, the processor 301 can be a central processing unit (CPU), which can be used to control the computer device, execute a software program, and process data of the software program. The computer device can further include the communication unit 305 to realize input (reception) and output (transmission) of signals.

[0097] The processor 301 can be a general-purpose processor or a special-purpose processor. For example, the processor 301 can be a central processing unit (CPU), which can be used to control the computer device, execute a software program, and process data of the software program. The computer device can further include the communication unit 305 to realize input (reception) and output (transmission) of signals.

[0098] For example, the computer device can be a chip, and the communication unit 305 can be an input and / or output circuit of the chip, or the communication unit 305 can be a communication interface of the chip. The chip can be a component of a terminal device or a network device or other device.

[0099] For example, the computer device can be a terminal device or a server, and the communication unit 305 can be a transceiver of the terminal device or the server, or the communication unit 305 can be a transceiver circuit of the terminal device or the server.

[0100] The computer device can include one or more memories 302, which have programs 304 stored thereon. The programs 304 can be run by the processor 301 to generate instructions 303, so that the processor 301 executes the method described in the above method embodiments according to the instructions 303. Optionally, the memory 302 can also store data (such as a target audit model). Optionally, the processor 301 can also read the data stored in the memory 302. The data can be stored in the same storage address as the program 304, or the data can be stored in a different storage address from the program 304.

[0101] The processor 301 and the memory 302 can be separately arranged or integrated together, for example, integrated on a system on chip (SOC) of the terminal device.

[0102] It should be understood that each step of the above method embodiments can be accomplished by logic circuitry in the form of hardware within the processor 301 or by instructions in the form of software, and the processor 301 can be a CPU, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof.

[0103] Those skilled in the art will appreciate that embodiments of the application can be devised for a method, a system, or a computer program product. Accordingly, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application can take the form of a computer program product on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage devices, etc.) embodying computer readable program code.

[0104] For example, in some embodiments, the present application also provides a computer readable storage medium, wherein instructions or codes are stored in the computer readable storage medium, and when the instructions or codes are run on a computer, the computer is caused to perform the above-mentioned automobile bumper grabbing displacement method.

[0105] While the preferred embodiments of the application have been described, additional variations and modifications can be made to the embodiments by those skilled in the art once they learn of the basic inventive concepts. Therefore, the appended claims are intended to encompass within their scope all such variations and modifications as are included within the scope of the application.

[0106] Obviously, various modifications and changes can be made to the present application by those skilled in the art without departing from the spirit and scope of the present application. Accordingly, the present application intends to include all such modifications and changes as fall within the scope of the claims and their equivalents.

Claims

1. A method of grabbing and displacing an automobile bumper, comprising: The method comprises the following steps: initializing a selected gripping point of a robot to a vehicle bumper, and monitoring touch force feedback information of the selected gripping point in a position changing motion of the vehicle bumper; generating a position changing trajectory of the vehicle bumper in the position changing motion through a space pose of the selected gripping point and a target placement point of the vehicle bumper, extracting a torque distribution feature of the selected gripping point when the robot performs the position changing motion according to the position changing trajectory from the touch force feedback information, and then performing inertia deformation compensation on the torque distribution feature to obtain a position changing load torque of the selected gripping point at a current position changing point in the position changing trajectory; when the position changing load torque is greater than a permissible torque threshold of the selected gripping point in the vehicle bumper, obtaining a position changing speed of the robot at the current position changing point, then matching a safe deceleration of the position changing speed, and determining a torque overrun value of the selected gripping point in the vehicle bumper at the current position changing point; using the torque overrun value and the safe deceleration to attenuate and adjust the position changing speed of the robot at the current position changing point.

2. The method of claim 1, wherein, The generating of the position changing trajectory of the vehicle bumper in the position changing motion through the space pose of the selected gripping point and the target placement point of the vehicle bumper specifically comprises: initializing a static position changing path between the space pose of the selected gripping point and the target placement point of the vehicle bumper; performing static collision avoidance on the static position changing path to obtain the position changing trajectory of the vehicle bumper in the position changing motion.

3. The method of claim 1, wherein, The extracting of the torque distribution feature of the selected gripping point when the robot performs the position changing motion according to the position changing trajectory from the touch force feedback information specifically comprises: obtaining torque information of the selected gripping point in a sensor coordinate system from the touch force feedback information; converting the torque information from the sensor coordinate system to a robot end tool coordinate system to obtain an axial torque matrix of the robot in the robot end tool coordinate system; extracting a plurality of axial torque values in the axial torque matrix to obtain the torque distribution feature of the selected gripping point when the robot performs the position changing motion according to the position changing trajectory.

4. The method of claim 1, wherein, The performing of the inertia deformation compensation on the torque distribution feature to obtain the position changing load torque of the selected gripping point at the current position changing point in the position changing trajectory specifically comprises: obtaining a static torque of a gravity of the vehicle bumper in the robot end tool coordinate system; determining an inertia torque of the selected gripping point at the current position changing point based on an angular acceleration and an inertia tensor of the current position changing point in the position changing trajectory; performing compensation on the torque distribution feature using the static torque and the inertia torque to obtain the position changing load torque of the selected gripping point at the current position changing point in the position changing trajectory.

5. The method of claim 1, wherein, The matching of the safe deceleration of the position changing speed specifically comprises: inquiring a maximum safe deceleration of the position changing speed; setting an inertia safety coefficient of the selected gripping point based on a device model of the robot; determining the safe deceleration of the position changing speed through the maximum safe deceleration and the inertia safety coefficient.

6. The method of claim 1, wherein, The determining of the torque overrun value of the selected gripping point in the vehicle bumper at the current position changing point specifically comprises: obtaining a permissible torque threshold of the selected gripping point in the vehicle bumper and the position changing load torque of the current position changing point; The moment overrun value of the selected gripping point of the automobile bumper at the current displacement point is determined by the allowable moment threshold and the displacement load moment.

7. The method of claim 1, wherein, The attenuation adjustment of the displacement speed of the manipulator at the current displacement point using the moment overrun value and the safe deceleration specifically includes: calculating a displacement speed adjustment amount of the manipulator at the current displacement point based on the moment overrun value; determining an attenuation gradient and an attenuation time of the displacement speed of the manipulator at the current displacement point by the safe deceleration and the displacement speed adjustment amount; and adjusting the displacement speed of the manipulator at the current displacement point using the attenuation gradient and the attenuation time.

8. A vehicle bumper grab-displacement system characterized by, comprise: a monitoring module configured to initialize a selected gripping point of a manipulator to an automobile bumper, and monitor touch force feedback information of the selected gripping point of the automobile bumper in displacement movement; a processing module configured to generate a displacement trajectory of the automobile bumper in displacement movement by a spatial pose of the selected gripping point and a target placement point of the automobile bumper, extract a moment distribution feature of the selected gripping point of the manipulator when the manipulator moves according to the displacement trajectory from the touch force feedback information, and then compensate the moment distribution feature for inertia deformation to obtain a displacement load moment of the selected gripping point at a current displacement point in the displacement trajectory; the processing module is further configured to, when the displacement load moment is greater than an allowable moment threshold of the selected gripping point of the automobile bumper, obtain a displacement speed of the manipulator at the current displacement point in the displacement trajectory, match a safe deceleration of the displacement speed, and determine a moment overrun value of the selected gripping point of the automobile bumper at the current displacement point; an execution module configured to use the moment overrun value and the safe deceleration to perform attenuation adjustment of the displacement speed of the manipulator at the current displacement point.

9. A computer device, comprising: The computer device comprises a memory and a processor, the memory is used to store a computer program, and the processor is used to call and run the computer program from the memory, so that the computer device executes the automobile bumper gripping and displacement method in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores instructions or codes, when the instructions or codes are run on a computer, so that the computer executes the automobile bumper gripping and displacement method in any one of claims 1 to 7.

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