Mechanical arm preheating method and system and storage medium

Abstract

The invention relates to the technical field of mechanical arm control, and provides a mechanical arm preheating method and system and a storage medium, and the mechanical arm preheating method comprises the following steps that S1, the pose of the tail end of a mechanical arm is fixed; s2, according to the statics equilibrium relation between the tail end of the mechanical arm and the mechanical arm joints, the preheating joint angle of each mechanical arm joint is obtained when the mechanical arm joints reach the first torque output state; and S3, the mechanical arm joint is controlled according to the preheating joint angle, so that a motor of the mechanical arm joint is subjected to stalling spontaneous heating. Motor stalling spontaneous heating of the mechanical arm joint can be achieved, a special external preheating device is not needed, and the preheating cost is low; moreover, the heat loss is less, and the heating efficiency of the lubricating grease is higher; without additional wiring, the problems of pulling and collision of additional lines are avoided, so that the normal work of the mechanical arm is prevented from being influenced.

Description

Technical Field

[0001] This invention relates to the field of robotic arm control technology, and more specifically to a robotic arm preheating method, system, and storage medium. Background Technology

[0002] Existing robotic arms typically require an operating temperature above 0 degrees Celsius. At low temperatures, the lubricating grease at the joints tends to solidify, causing difficulty in movement or even jamming. Therefore, under low-temperature conditions, a dedicated external preheating device is often needed to heat the lubricating grease at the joints, which is costly. Moreover, these additional preheating devices often only heat the outside of the robotic arm, while the joint lubrication points are often located internally, resulting in low heating efficiency and high energy consumption. Adding dedicated preheating devices to each joint of the robotic arm would lead to complex wiring, making the wires prone to pulling and collisions, reducing the reliability of the robotic arm's operation. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a method, system, and storage medium for preheating a robotic arm. This method enables self-heating of the motor in the robotic arm joint when it is stalled, eliminating the need for a dedicated external preheating device and reducing preheating costs. Furthermore, it minimizes heat loss and increases the heating efficiency of the lubricating grease. It also eliminates the need for additional wiring, preventing additional wiring pulls and collisions, thus avoiding any impact on the normal operation of the robotic arm.

[0004] The technical solution adopted in this invention is as follows:

[0005] A method for preheating a robotic arm, the robotic arm including an end effector and at least two joints, includes the following steps: S1, fixing the position of the end effector; S2, obtaining the preheating joint angle of each joint when the joints reach a first torque output state based on the static equilibrium relationship between the end effector and the joints; S3, controlling the joints based on the preheating joint angles to cause the motors of the joints to self-heat from a stall state.

[0006] According to one embodiment of the present invention, the first torque of each of the robotic arm joints is greater than 0 and not greater than the balance torque threshold of the robotic arm joint. The balance torque threshold is the difference between the maximum output torque of the joint motor of the robotic arm joint and the torque of the joint motor itself when the end pose of the robotic arm is fixed and the robotic arm is not subjected to any external force other than gravity.

[0007] According to an embodiment of the present invention, step S2 specifically includes: S21, establishing the pose transfer matrix between the robotic arm joint and the robotic arm end effector; S22, based on the pose transfer matrix, calculating the force and torque output by the robotic arm end effector when the robotic arm joint reaches the first torque output state under static equilibrium conditions; S23, based on the force and torque of the robotic arm end effector and the stiffness transfer matrix of the robotic arm, obtaining the preheating joint angle of each robotic arm joint.

[0008] According to an embodiment of the present invention, step S22 specifically includes: extracting the mapping relationship between the pose parameters of the robotic arm end effector and the joint angles of the robotic arm joints based on the pose transfer matrix; taking the partial derivative of the mapping relationship to obtain the coefficient matrix of the torque transfer from the robotic arm joints to the robotic arm end effector under static equilibrium conditions; and calculating the force and torque output by the robotic arm end effector when the robotic arm joints reach the first torque output state based on the coefficient matrix and the first torque of each robotic arm joint.

[0009] According to one embodiment of the present invention, step S23 includes: obtaining the coordinate interference and Euler angle interference of the end effector of the robotic arm based on the force and torque at the end effector of the robotic arm and the stiffness transfer matrix of the robotic arm; and obtaining the preheating joint angle of each robotic arm joint based on the coordinate interference and Euler angle interference of the end effector of the robotic arm.

[0010] According to an embodiment of the present invention, the method further includes the following steps: S4, detecting the temperature of each of the robotic arm joints, and when the temperature of the robotic arm joint is greater than or equal to a preset temperature threshold, setting the robotic arm joint as a qualified robotic arm joint and setting the other robotic arm joints as unqualified robotic joints; S5, based on the static balance relationship between the robotic arm end and the robotic arm joint, obtaining the updated preheating joint angle of each of the robotic arm joints when the unqualified robotic arm joint reaches the first torque output state and the qualified robotic arm joint is in the second torque output state, wherein the second torque is 0; S6, controlling the robotic arm joints according to the updated preheating joint angle, so that the motor of the unqualified robotic arm joint is stalled and self-heating.

[0011] In addition, to achieve the above objectives, the present invention also proposes a robotic arm preheating system.

[0012] A robotic arm preheating system, the robotic arm including a robotic arm end effector and at least two robotic arm joints, comprising: a fixing module for fixing the position and orientation of the robotic arm end effector; a first calculation module for obtaining the preheating joint angle of each robotic arm joint when the robotic arm joint reaches a first torque output state based on the static equilibrium relationship between the robotic arm end effector and the robotic arm joint; and a control module for controlling the robotic arm joints according to the preheating joint angle, so that the motors of the robotic arm joints self-heat by stalling.

[0013] According to one embodiment of the present invention, the fixing module includes a fixing device that matches the end effector of the robotic arm. The fixing device maintains a fixed posture when the motor of the robotic arm joint is stalled and self-heating, thereby fixing the posture of the end effector of the robotic arm.

[0014] According to one embodiment of the present invention, the robotic arm preheating system further includes: a detection module, which is used to detect the temperature of each robotic arm joint, and when the temperature of the robotic arm joint is greater than or equal to a preset temperature threshold, the robotic arm joint is set as a qualified robotic arm joint, and other robotic arm joints are set as unqualified robotic arms joints; an update module, which is used to obtain the update preheating joint angle of each robotic arm joint when the unqualified robotic arm joint reaches a first torque output state and the qualified robotic arm joint is in a second torque output state, based on the static balance relationship between the robotic arm end and the robotic arm joint, wherein the second torque is 0; and a control module controls the robotic arm joints according to the update preheating joint angle, so that the motor of the unqualified robotic arm joint is stalled and self-heating.

[0015] In addition, to achieve the above objectives, the present invention also proposes a storage medium.

[0016] A storage medium storing a robotic arm preheating program, which, when executed by a processor, implements the steps of the robotic arm preheating method described above.

[0017] The beneficial effects of this invention are:

[0018] The robotic arm preheating method of this invention fixes the position of the robotic arm end effector and obtains and controls the preheating joint angle of each robotic arm joint based on the static balance relationship between the robotic arm end effector and the robotic arm joint. This achieves self-heating of the robotic arm joint motor when stalled, eliminating the need for a dedicated external preheating device and reducing preheating costs. Moreover, the self-heating of the motor when stalled is generated inside the robotic arm, resulting in less heat loss, higher heating efficiency for the lubricating grease, and less energy waste. It also eliminates the need for additional wiring, avoiding additional wiring pulling and collision problems, thus preventing any impact on the normal operation of the robotic arm. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a six-axis serial robotic arm in the prior art;

[0020] Figure 2 This is a flowchart of the robotic arm preheating method according to an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of the preheating of a six-axis serial robotic arm according to a specific embodiment of the present invention;

[0022] Figure 4 This is a schematic diagram of the coordinate system and Euler angle direction of the end effector of a robotic arm according to a specific embodiment of the present invention;

[0023] Figure 5 This is a flowchart of a robotic arm preheating method according to a specific embodiment of the present invention;

[0024] Figure 6 This is a block diagram of the robotic arm preheating system according to an embodiment of the present invention;

[0025] Figure 7 This is a block diagram of a robotic arm preheating system according to a specific embodiment of the present invention. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] In existing technologies, robotic arms mostly include an end effector and at least two joints to achieve multi-degree-of-freedom control of the end effector. This invention combines... Figure 1 The six-axis serial robotic arm shown illustrates the working principle of the present invention. In some other embodiments of the present invention, the robotic arm may also be a four-axis serial robotic arm, a parallel robotic arm, a serial-parallel robotic arm, etc., and this embodiment is not limited thereto.

[0028] like Figure 2 As shown, the robotic arm preheating method of this embodiment includes the following steps S1 to S3:

[0029] S1, the pose of the fixed end effector of the robotic arm.

[0030] like Figure 1As shown, the six-axis serial robotic arm 1 may include: a first joint 101, a second joint 102, a third joint 103, a fourth joint 104, a fifth joint 105, and a sixth joint 106. Each joint is equipped with a joint motor, which can rotate at corresponding angles, namely θ1, θ2, θ3, θ4, θ5, and θ6, respectively, thereby driving the end effector of the robotic arm to a specified spatial position (x). H ,y H ,z H ) and attitude (α) H ,β H ,γ H The six-axis tandem robotic arm 1 is typically mounted on a fixed base 2. When preheating of the robotic arm is required, the fixed base 2 is usually stationary. A fixing device 3, matching the end effector of the robotic arm, is installed near the robotic arm. Figure 3 As shown, the fixing device 3 is kept in a fixed position when the motor of the robotic arm joint is stalled and self-heating, so as to fix the position of the end of the robotic arm.

[0031] It is understandable that when fixing the position of the end effector of the robotic arm, the end effector can be fixed directly when installing the fixing device 3; or the fixing device 3 can be installed first, and then the end effector of the robotic arm can be controlled to move to a position that matches the fixing device 3, so that the fixing device 3 can provide a reaction force to the end effector of the robotic arm that is opposite to the output force of the end effector.

[0032] With the position of the robotic arm's end effector fixed, commands are sent to perform translational and torsional movements in space, generating force and torque output. This force and torque output is ultimately formed by the torque provided by the joint motors of each robotic arm joint. As the joint motors output torque, the corresponding motor current increases. Since the internal resistance of each joint motor is constant, the increased current leads to an increase in heat generated by the motor resistance, thus achieving a heating effect. After the joint motor temperature rises, the heat is transferred from the internal motor wires to the joint grease lubrication points, raising the grease temperature and reducing its viscosity, thereby ensuring good lubrication of the joint and preventing jamming or immobility.

[0033] S2, based on the static balance relationship between the robotic arm end effector and the robotic arm joints, the preheating joint angle of each robotic arm joint when the robotic arm joint reaches the first torque output state is obtained. The first torque of each robotic arm joint is greater than 0 and not greater than the balance torque threshold of that robotic arm joint. The balance torque threshold is the difference between the maximum output torque of the joint motor of the robotic arm joint and the torque of the joint motor itself when the robotic arm end effector is fixed in position and the robotic arm is not subjected to any external force other than gravity. This ensures that the motor does not overload and burn out, and heats each joint as quickly as possible. In some other embodiments of the present invention, the magnitude of the first torque can also be adjusted according to actual needs; this embodiment does not impose any limitations on this.

[0034] In one embodiment of the present invention, step S2 specifically includes steps S21 to S23:

[0035] S21, establish the pose transfer matrix between the robotic arm joints and the robotic arm end effector.

[0036] Specifically, based on the joint angles of each robotic arm joint and the robotic arm length between each joint, a transformation relationship between the robotic arm end-effector coordinate system and the global coordinate system can be established, namely the pose transfer matrix T, which is expressed by the following formula:

[0037]

[0038] In the formula, T 11 ~T 33 Let T be the rotation matrix. 14 ~T 34 It is a translation vector.

[0039] S22, based on the pose transfer matrix, calculates the force and torque output by the end effector of the robotic arm when the joints of the robotic arm reach the first torque output state under static equilibrium conditions.

[0040] In one embodiment of the present invention, step S22 specifically includes the following steps S221 to S223:

[0041] S221, Based on the pose transfer matrix, extract the mapping relationship between the pose parameters of the robotic arm end effector and the joint angles of the robotic arm joints, that is:

[0042]

[0043] In the formula, x H y H z H and α H β H γ HThese represent the X, Y, and Z coordinates of the robotic arm's end effector and the Euler angles of rotation about the X, Y, and Z axes, respectively. The coordinate system and Euler angle directions of the robotic arm's end effector are as follows: Figure 4 As shown, f1(T)~f6(T) represent the mapping relationship between the pose parameters of the end effector of the robot arm and the joint angles of the first to sixth joints extracted from the pose transfer matrix T, respectively. g1(θ1,θ2,θ3,θ4,θ5,θ6)~g6(θ1,θ2,θ3,θ4,θ5,θ6) represent the mapping functions corresponding to f1(T)~f6(T), respectively.

[0044] S222, taking the partial derivative with respect to the mapping relationship, yields the coefficient matrix J of the torque transmission from the robotic arm joints to the robotic arm end effector under static equilibrium conditions. H ,Right now:

[0045]

[0046] S223, based on the coefficient matrix and the first torque of each robotic arm joint, calculate the force and torque output at the end of the robotic arm when the robotic arm joint reaches the first torque output state.

[0047] The first torque T of each robotic arm joint 1max T 2max T 3max T 4max T 5max T 6max Substituting into the following formula, we obtain the force and torque output by the robotic arm's end effector:

[0048]

[0049] Among them, F Hx F Hy F Hz T represents the force output by the robotic arm's end effector along the X, Y, and Z axes, respectively. Hx T Hy T Hz These are the torques output by the end effector of the robotic arm around the X, Y, and Z axes, respectively.

[0050] S23, based on the force and torque at the end of the robotic arm and the stiffness transfer matrix of the robotic arm, obtain the preheating joint angle of each robotic arm joint.

[0051] In one embodiment of the present invention, step S23 may include the following steps S231 and S232:

[0052] S231, based on the force and torque at the end of the robotic arm and the stiffness transfer matrix of the robotic arm, obtain the coordinate interference and Euler angle interference at the end of the robotic arm.

[0053] The formulas for calculating the coordinate interference and Euler angle interference at the end effector of the robotic arm are as follows:

[0054]

[0055] In the formula, d xH d yH d zH d αH d βH d γH These represent the coordinate interference along the X, Y, and Z axes of the robotic arm's end effector, and the Euler angle interference for rotation about the X, Y, and Z axes, respectively, where Δ xH ,、Δ yH Δ zH Δ αH Δ βH Δ γH During the preheating process, the force and torque output by the robotic arm's end effector are respectively F. Hx F Hy F Hz T Hx T Hy T Hz The resulting coordinate displacement deviations along the X, Y, and Z axes, as well as the Euler angle deviations due to rotation around the X, Y, and Z axes, are calculated using the following formulas:

[0056]

[0057] In the formula, K H The stiffness transfer matrix of the robotic arm can be derived from the stiffness transfer matrix of each joint of the robotic arm, or it can be obtained through stiffness experimental measurement.

[0058] The principles of formulas (5) and (6) are as follows: Based on the relationship between force and deformation, if the output force and torque at the end of the robotic arm are F Hx F Hy F Hz T Hx T Hy T Hz Then the displacement of the robotic arm end effector and the force and torque at the end effector of the robotic arm satisfy the following conditions:

[0059]

[0060] Based on formula (7), the output force and torque of the robotic arm end effector can be derived by working backwards as F. Hx F Hy F Hz T Hx T Hy T HzThe formula for calculating the coordinate displacement deviation along the X, Y, and Z axes and the Euler angle deviation around the X, Y, and Z axes is formula (6).

[0061] According to the principle that the action and reaction forces are equal in magnitude and opposite in direction, when the position of the end of the robotic arm is fixed, in order to generate a force opposite to the force output by the end of the robotic arm and a torque opposite to the torque output by the end of the robotic arm, it is necessary to apply a reverse displacement and rotation angle to the robotic arm command, so that the end of the robotic arm and the fixed device 3 have a relative misalignment potential, i.e., formula (5).

[0062] By applying this displacement and rotation angle, the end effector of the robotic arm can generate force and torque that satisfy the first torque output state of each robotic arm joint under static equilibrium conditions, so that each joint arm can simultaneously reach the first torque output state, thereby rapidly increasing the temperature at the motor of the robotic arm joint and shortening the preheating time.

[0063] S232, based on the coordinate interference (d) of the robotic arm end effector. xH d yH d zH ) and Euler angle interference (d αH d βH d γH ), thus obtaining the preheated joint angle of each robotic arm joint.

[0064] Specifically, control commands for coordinate interference and Euler angle interference can be directly given to the end effector of the robotic arm. Based on the inverse kinematics calculation built into the robotic arm itself, the interference can be automatically allocated to each robotic arm joint (first joint 101, second joint 102, third joint 103, fourth joint 104, fifth joint 105 and sixth joint 106), thus obtaining the preheating joint angle of each robotic arm joint. Alternatively, the interference can be evenly distributed to each robotic arm joint through inverse kinematics calculation, thereby controlling each robotic arm joint and obtaining the preheating joint angle of each robotic arm joint.

[0065] S3 controls the robotic arm joints based on the preheating joint angle, causing the motors of the robotic arm joints to stall and generate heat.

[0066] One or more joints in a robotic arm may reach a preset temperature threshold, i.e., meet the normal operating temperature of the robotic arm, before other joints. In this case, the motors of these joints may experience overheating due to continuous stalling. Considering the above problems, in one embodiment of the present invention, such as... Figure 5 As shown, the robotic arm preheating method may further include the following steps S4 to S6, which ensure that the robotic arm joints that have reached the specified temperature no longer need to be heated, while continuing to preheat the remaining robotic arm joints that have not reached the specified temperature:

[0067] S4. Detect the temperature of each robotic arm joint. When the temperature of a robotic arm joint is greater than or equal to a preset temperature threshold, set that robotic arm joint as a qualified robotic arm joint, and set the other robotic arm joints as unqualified robotic arm joints. The preset temperature threshold can be set based on the melting temperature of the lubricating grease at the robotic arm joint, or adjusted according to actual conditions; this embodiment does not impose any limitations on this.

[0068] S5, based on the static balance relationship between the end effector and the joints of the robotic arm, the update preheating joint angle of each robotic arm joint is obtained when the substandard robotic arm joint reaches the first torque output state and the compliant robotic arm joint is in the second torque output state, where the second torque is 0. The calculation process of the update preheating joint angle of each robotic arm joint can be referred to step S2, and will not be repeated here in this embodiment.

[0069] S6 controls the robotic arm joints based on the updated preheating joint angle, causing the motors of robotic arm joints that fail to meet the standard to stall and self-heat.

[0070] Understandably, steps S4 to S6 can be repeated until the temperature of all robotic arm joints is greater than or equal to the preheating temperature threshold, thus completing the preheating process of the entire robotic arm.

[0071] According to the robotic arm preheating method of the present invention, by fixing the position of the robotic arm end effector, the preheating joint angle of each robotic arm joint is obtained and controlled based on the static balance relationship between the robotic arm end effector and the robotic arm joint, so as to realize the self-heating of the motor stall in the robotic arm joint. No special external preheating device is required, and the preheating cost is low. Moreover, the self-heating of the motor stall is generated inside the robotic arm, with less heat loss, higher heating efficiency of lubricating grease, and less energy waste. No additional wiring is required, and no additional wiring pulling or collision problems are caused, thereby avoiding affecting the normal operation of the robotic arm.

[0072] Corresponding to the above-described robotic arm preheating method, this invention also proposes a robotic arm preheating system. Since the system embodiments of this invention correspond to the method embodiments described above, details not disclosed in the system embodiments can be found in the method embodiments described above, and will not be repeated here.

[0073] like Figure 6As shown, the robotic arm preheating system of this embodiment includes a fixing module, a first calculation module, and a control module. The fixing module is used to fix the position of the robotic arm end effector. The first calculation module is used to obtain the preheating joint angle of each robotic arm joint when the robotic arm joint reaches the first torque output state based on the static balance relationship between the robotic arm end effector and the robotic arm joint. The control module controls the robotic arm joints according to the preheating joint angle, so that the motors of the robotic arm joints are stalled and self-heating. The first torque of each robotic arm joint is greater than 0 and not greater than the balance torque threshold of the robotic arm joint. The balance torque threshold is the difference between the maximum output torque of the joint motor of the robotic arm joint and the torque of the joint motor itself when the position of the robotic arm end effector is fixed and the robotic arm is not subjected to any external force other than gravity. This ensures that the motors are heated as quickly as possible without overloading and burning out. In some other embodiments of this invention, the magnitude of the first torque can also be adjusted according to actual needs, and this embodiment does not limit this adjustment.

[0074] The robotic arm preheating system according to an embodiment of the present invention, by fixing the position of the robotic arm end effector, obtains and controls the preheating joint angle of each robotic arm joint based on the static balance relationship between the robotic arm end effector and the robotic arm joint, thereby realizing the self-heating of the motor stall in the robotic arm joint, eliminating the need for a dedicated external preheating device and reducing preheating costs; moreover, the self-heating of the motor stall is generated inside the robotic arm, resulting in less heat loss, higher heating efficiency for the lubricating grease, and less energy waste; no additional wiring is required, avoiding additional wiring pulling and collision problems, thus preventing interference with the normal operation of the robotic arm.

[0075] like Figure 3 As shown, in one embodiment of the present invention, the fixing module 30 may include a fixing base 2 for mounting the robotic arm and a fixing device 3 that matches the end effector of the robotic arm. When the robotic arm needs to be preheated, the fixing base 2 is usually stationary. The fixing device 3 that matches the end effector of the robotic arm is installed near the robotic arm so that the fixing device 3 remains in a fixed position when the motor of the robotic arm joint is stalled and self-heating, thereby limiting the displacement and torsion of the end effector in space and fixing the position of the end effector of the robotic arm. The fixing device 3 may be installed near the end effector of the robotic arm and may be installed on the work platform or wall in a horizontal or vertical direction. This embodiment does not impose any limitations on this.

[0076] In one embodiment of the present invention, the first calculation module 40 may include a modeling unit, an output calculation unit, and a preheating joint angle calculation unit. The modeling unit is used to establish the pose transfer matrix between the robotic arm joints and the robotic arm end effector. The output calculation unit is used to calculate, based on the pose transfer matrix, the force and torque output by the robotic arm end effector when the robotic arm joints reach the first torque output state under static equilibrium conditions. The preheating joint angle calculation unit is used to obtain the preheating joint angle of each robotic arm joint based on the force and torque of the robotic arm end effector and the stiffness transfer matrix of the robotic arm.

[0077] The specific implementation of the modeling unit in establishing the pose transfer matrix can be found in step S21 of the above-described robotic arm preheating method. The specific implementation of the output calculation unit in calculating the force and torque output at the end of the robotic arm can be found in step S22 of the above-described robotic arm preheating method. The specific implementation of the preheating joint angle calculation unit in calculating the preheating joint angle of each robotic arm joint can be found in step S23 of the above-described robotic arm preheating method. These details will not be repeated here.

[0078] One or more joints in a robotic arm may reach a preset temperature threshold, i.e., meet the normal operating temperature of the robotic arm, before other joints. In this case, the motors of these joints may experience overheating due to continuous stalling. Considering the above problems, in one embodiment of the present invention, such as... Figure 7 As shown, the robotic arm preheating system may further include: a detection module 60 and an update module 70. The detection module 60 is used to detect the temperature of each robotic arm joint. When the temperature of a robotic arm joint is greater than or equal to a preset temperature threshold, the robotic arm joint is set as a qualified robotic arm joint, and other robotic arm joints are set as unqualified robotic arms. The update module 70 is used to obtain the update preheating joint angle of each robotic arm joint when the unqualified robotic arm joint reaches the first torque output state and the qualified robotic arm joint is in the second torque output state, based on the static balance relationship between the robotic arm end and the robotic arm joint. The second torque is 0. The calculation process of the update preheating joint angle of each robotic arm joint can be referred to step S2, which will not be repeated here in this embodiment. The control module 50 controls the robotic arm joints according to the update preheating joint angle, so that the motor of the unqualified robotic arm joint is stalled and self-heated.

[0079] It is understandable that the detection module 60 and the update module 70 can be implemented cyclically after the first calculation module 40 is implemented, until the temperature of all robotic arm joints is greater than or equal to the preheating temperature threshold, thus completing the preheating process of the entire robotic arm.

[0080] In addition, to achieve the above objectives, the present invention also proposes a storage medium storing a robotic arm preheating program, which, when executed by a processor, implements the steps of the robotic arm preheating method described above.

[0081] According to the storage medium of the present invention, when the processor executes the preheating of the robotic arm stored in the memory, it obtains and controls the preheating joint angle of each robotic arm joint based on the static balance relationship between the robotic arm end and the robotic arm joint by fixing the position of the robotic arm end. This achieves self-heating of the motor stall in the robotic arm joint, eliminating the need for a dedicated external preheating device and reducing preheating costs. Moreover, the self-heating of the motor stall is generated inside the robotic arm, resulting in less heat loss, higher heating efficiency for the lubricating grease, and less energy waste. It also eliminates the need for additional wiring, avoiding additional wiring pulling and collision problems, thereby preventing any impact on the normal operation of the robotic arm.

[0082] In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0083] In this invention, unless otherwise explicitly specified and limited, the terms "installation", "connection", "linking", "fixing", etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components.

[0084] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0085] The execution order of the steps shown in the flowchart is the preferred implementation. In other embodiments of the present invention, the order can be adjusted according to the functions involved in each step, for example, they can be executed simultaneously or in the reverse order.

[0086] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequential list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in connection with, an instruction execution system, apparatus, or device. For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit a program for use by, or in connection with, an instruction execution system, apparatus, or device.

[0087] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0088] Furthermore, the functional units in the various embodiments of the present invention can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

Claims

1. A method for preheating a robotic arm, the robotic arm comprising a robotic arm end effector and at least two robotic arm joints, characterized in that, Includes the following steps: S1, fix the position of the end effector of the robotic arm; S2, based on the static balance relationship between the end effector of the robotic arm and the joint of the robotic arm, obtain the preheating joint angle of each joint of the robotic arm when the joint of the robotic arm reaches the first torque output state; S3, control the robotic arm joint according to the preheating joint angle, so that the motor of the robotic arm joint is stalled and self-heated.

2. The robotic arm preheating method according to claim 1, characterized in that, The first torque of each of the robotic arm joints is greater than 0 and not greater than the balance torque threshold of the robotic arm joint. The balance torque threshold is the difference between the maximum output torque of the joint motor of the robotic arm joint and the torque of the joint motor itself when the end pose of the robotic arm is fixed and the robotic arm is not subjected to any external force other than gravity.

3. The robotic arm preheating method according to claim 1, characterized in that, Step S2 specifically includes: S21, Establish the pose transfer matrix between the robotic arm joints and the robotic arm end effector; S22, Based on the pose transfer matrix, calculate the force and torque output by the end of the robotic arm when the joint of the robotic arm reaches the first torque output state under static equilibrium conditions; S23, based on the force and torque at the end of the robotic arm and the stiffness transfer matrix of the robotic arm, the preheating joint angle of each of the robotic arm joints is obtained.

4. The robotic arm preheating method according to claim 3, characterized in that, Step S22 specifically includes: Based on the pose transfer matrix, the mapping relationship between the pose parameters of the robotic arm end effector and the joint angles of the robotic arm joints is extracted. Taking the partial derivative of the mapping relationship yields the coefficient matrix of the torque transmission from the joints of the robotic arm to the end effector of the robotic arm under static equilibrium conditions. Based on the coefficient matrix and the first torque of each of the robotic arm joints, calculate the force and torque output by the end of the robotic arm when the robotic arm joint reaches the first torque output state.

5. The robotic arm preheating method according to claim 3, characterized in that, Step S23 includes: Based on the force and torque at the end of the robotic arm, and the stiffness transfer matrix of the robotic arm, the coordinate interference and Euler angle interference at the end of the robotic arm are obtained. Based on the coordinate interference and Euler angle interference at the end of the robotic arm, the preheating joint angle of each robotic arm joint is obtained.

6. The robotic arm preheating method according to claim 1, characterized in that, It also includes the following steps: S4, detect the temperature of each of the robotic arm joints. When the temperature of the robotic arm joint is greater than or equal to a preset temperature threshold, set the robotic arm joint as a qualified robotic arm joint and set the other robotic arm joints as unqualified robotic joints. S5, based on the static balance relationship between the end effector of the robotic arm and the joint of the robotic arm, the update preheating joint angle of each robotic arm joint is obtained when the substandard robotic arm joint reaches the first torque output state and the qualified robotic arm joint is in the second torque output state, wherein the second torque is 0; S6, control the robotic arm joints according to the updated preheating joint angle, so that the motors of the substandard robotic arm joints are locked and self-heating.

7. A robotic arm preheating system, the robotic arm comprising a robotic arm end effector and at least two robotic arm joints, characterized in that, include: A fixing module is used to fix the position and orientation of the end effector of the robotic arm; The first calculation module is used to obtain the preheating joint angle of each robotic arm joint when the robotic arm joint reaches the first torque output state, based on the static balance relationship between the robotic arm end and the robotic arm joint. The control module controls the robotic arm joints according to the preheating joint angle, causing the motors of the robotic arm joints to stall and generate heat.

8. The robotic arm preheating system according to claim 7, characterized in that, The fixing module includes a fixing device that matches the end effector of the robotic arm. The fixing device maintains its position and posture when the motor of the robotic arm joint is stalled and self-heating, thereby fixing the position and posture of the end effector of the robotic arm.

9. The robotic arm preheating system according to claim 7, characterized in that, Also includes: The detection module is used to detect the temperature of each of the robotic arm joints. When the temperature of the robotic arm joint is greater than or equal to a preset temperature threshold, the robotic arm joint is set as a qualified robotic arm joint, and other robotic arm joints are set as unqualified robotic joints. The update module is used to determine the update preheating joint angle of each robotic arm joint when the substandard robotic arm joint reaches the first torque output state and the compliant robotic arm joint is in the second torque output state, based on the static balance relationship between the robotic arm end and the robotic arm joint, wherein the second torque is 0. The control module controls the robotic arm joints according to the updated preheating joint angle, causing the motors of the substandard robotic arm joints to stall and self-heat.

10. A storage medium, characterized in that, The storage medium stores a robotic arm preheating program, which, when executed by a processor, implements the steps of the robotic arm preheating method as described in any one of claims 1 to 6.

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