Load curve determination method and device and electronic equipment

Abstract

The embodiment of the invention provides a load curve determination method and device and electronic equipment, and relates to the technical field of robotics.The method comprises the steps that a robot inverse dynamics theoretical model is constructed, initial state parameters of all joint angles of a robot in a static stretching state are determined, a target joint in the robot is determined, and a load curve is determined; based on the initial state parameters and an inverse dynamics theoretical model, initial motor equivalent output torque of each target joint is determined, and when the initial motor equivalent output torque of each target joint meets a preset condition, the maximum allowable load mass of the tail end of the robot under the fixed load gravity center offset is calculated; according to the method, the load curve is constructed on the basis of the fixed load gravity center offset and the maximum allowable load mass corresponding to the fixed load gravity center offset, and the relatively accurate load curve can be quickly generated, so that effective reference value is provided for user model selection.

Description

Technical Field

[0001] The present invention relates to the field of robotics, and in particular to a method and device for determining a load curve, and electronic equipment. Background Art

[0002] The robot load curve describes the relationship between the end-load center of gravity offset and mass, and serves as a reference for users when selecting a robotic arm. By establishing a quantitative model that describes the relationship between load mass and the corresponding allowable center of gravity offset, this curve provides theoretical support for evaluating a robot's dynamic load-bearing characteristics. Therefore, developing a load curve method that accurately reflects a robot's actual load capacity has important engineering applications.

[0003] Currently, there is a relative lack of publicly available documentation on load curve construction for collaborative robots. While load curves are widely used in industry as a product technical indicator, few companies have disclosed relevant patents or other technical documentation. Through empirical analysis of existing literature and reverse engineering of industrial product parameters, we can summarize two main approaches to load curve construction:

[0004] like Figure 1 As shown in the figure, the first method uses a linearly partitioned end-load mass to measure the corresponding allowable center of gravity offset, resulting in a curve that appears as a broken line segment. The second method, based on a linearly partitioned end-load mass, calculates the critical value of the horizontal coordinate of the center of mass using the maximum allowable torque and moment of inertia of the load at a fixed mass. By trying different load centers of mass, the torque of each joint at that time is calculated and compared with the maximum allowable torque to determine the critical value of the vertical coordinate. Ultimately, a set of concentric decreasing curves is obtained, representing the maximum allowable center of mass range for different mass levels.

[0005] The implementation process of obtaining the load curve of a collaborative robot based on the actual measurement method is very cumbersome, and requires continuous attempts to determine the allowable center of gravity offset under the same mass. At the same time, if the interval of the linear division of mass is large, there will be a problem of large error, which will mislead the user in selecting the model. The load curve of the collaborative robot obtained based on the theoretical calculation method presents multiple results, and the overall display effect is not intuitive enough. When calculating the lateral critical value of the load center of mass, the existing method relies on the empirical calculation formula of the maximum allowable torque and moment of inertia of the load. Its accuracy is uncertain and it is difficult to meet high-precision requirements. When determining the longitudinal critical value of the load center of mass, the method of trying different load center of mass positions, calculating the torque generated by each joint and comparing it with the maximum allowable torque can capture the load characteristics more accurately. However, when the number of robot joints is large, the amount of iterative calculation required increases significantly, resulting in a decrease in overall calculation efficiency. Summary of the Invention

[0006] The object of the present invention is to provide a load curve determination method, device and electronic equipment, which can improve the accuracy of determining the load curve of a robot.

[0007] In order to achieve the above objectives, the technical solutions adopted in the embodiments of the present application are as follows:

[0008] In a first aspect, an embodiment of the present application provides a method for determining a load curve, the method comprising:

[0009] Construct a theoretical model of robot inverse dynamics;

[0010] Determining initial state parameters of each joint angle of the robot when the robot is in a stationary extended state;

[0011] determining a target joint in the robot;

[0012] Determine the initial motor equivalent output torque of each target joint based on the initial state parameters and the inverse dynamics theoretical model;

[0013] When the initial motor equivalent output torque of each target joint meets a preset condition, calculating the maximum allowable load mass of the end of the robot under a fixed load center of gravity offset;

[0014] A load curve is constructed based on the fixed load center of gravity offset and the maximum allowable load mass corresponding to the fixed load center of gravity offset.

[0015] In an optional embodiment, the method further comprises:

[0016] For each target joint, the initial motor equivalent output torque of the target joint is compared with the maximum torque allowed by the start-stop of the joint harmonic reducer corresponding to the target joint;

[0017] When the initial motor equivalent output torque of each target joint is less than the corresponding joint harmonic reducer start-stop allowable maximum torque, it is determined that the initial motor equivalent output torque of each target joint meets the preset conditions.

[0018] In an optional embodiment, when the initial motor equivalent output torque of each target joint satisfies a preset condition, the step of calculating the maximum allowable load mass of the end of the robot under a fixed load center of gravity offset includes:

[0019] When the initial motor equivalent output torque of each target joint meets a preset condition, the variable i is used to traverse the fixed load center of gravity offset table, wherein the fixed load center of gravity offset table includes each fixed load center of gravity offset in an increasing relationship;

[0020] Determine the maximum allowable load mass under the i-th fixed load center of gravity offset, and use the variable j to traverse the end load mass table to determine the maximum allowable load mass under the i-th fixed load center of gravity offset, wherein the end load mass table includes each end load mass in an increasing relationship.

[0021] In an optional embodiment, the step of determining the maximum allowable load mass under the i-th fixed load center of gravity offset by traversing the end load mass table using the variable j to determine the i-th fixed load center of gravity offset comprises:

[0022] Determine the equivalent output torque of the first motor corresponding to the j-1th end load mass of each target joint under the i-th fixed load center of gravity offset;

[0023] Determine the equivalent output torque of the second motor corresponding to the j-th end load mass of each target joint under the i-th fixed load center of gravity offset;

[0024] Calculating a first difference between the equivalent output torque of the first motor and the maximum torque;

[0025] Calculating a second difference between the equivalent output torque of the second motor and the maximum torque;

[0026] Determining a maximum allowable load mass at an i-th fixed load center of gravity offset based on the equivalent output torque of the second motor and the maximum torque corresponding to the target joint;

[0027] or;

[0028] Based on any one of the second motor's equivalent output torque, the maximum torque, and the first difference and the second difference corresponding to the second motor's equivalent output torque, the maximum allowable load mass at the i-th fixed load center of gravity offset is determined.

[0029] In an optional embodiment, the target joint includes a first target joint and a second target joint, the first target joint is arranged in front of the second target joint, and the step of determining the maximum allowable load mass under the i-th fixed load center of gravity offset based on the equivalent output torque of the second motor and the maximum torque corresponding to the target joint includes:

[0030] comparing the equivalent output torque of the second motor corresponding to the second target joint with the maximum torque corresponding to the second target joint;

[0031] When the second motor equivalent output torque corresponding to the second target joint is less than the maximum torque corresponding to the second target joint, calculating an absolute value of a third difference between the second motor equivalent output torque corresponding to the first target joint and the maximum torque corresponding to the first target joint;

[0032] comparing the absolute value of the third difference with a termination threshold;

[0033] When the absolute value of the third difference is less than or equal to the termination threshold, the j-th end load mass is used as the maximum allowable load mass under the i-th fixed load center of gravity offset.

[0034] In an optional embodiment, the step of determining the maximum allowable load mass at the i-th fixed load center of gravity offset based on any one of the second motor's equivalent output torque, the maximum torque, and the first difference and the second difference corresponding to the second motor's equivalent output torque includes:

[0035] Calculating an absolute value of a fourth difference between an equivalent output torque of the second motor corresponding to the first target joint and a maximum torque corresponding to the first target joint;

[0036] comparing the absolute value of the fourth difference with the termination threshold;

[0037] When the absolute value of the fourth difference is greater than the termination threshold, calculating a first product of the first difference of the first target joint and the second difference of the first target joint;

[0038] When the first product is zero or -1, the j-th end load mass is used as the maximum allowable load mass under the i-th fixed load center of gravity offset.

[0039] In an optional embodiment, the step of determining the maximum allowable load mass at the i-th fixed load center of gravity offset based on the equivalent output torque of the second motor and the maximum torque corresponding to the target joint includes:

[0040] Calculating a fifth difference between the second motor equivalent output torque of the second target joint and the maximum torque corresponding to the second target joint;

[0041] comparing the fifth difference value with the termination threshold;

[0042] When the fifth difference is less than or equal to the termination threshold, the j-th end load mass is used as the maximum allowable load mass under the i-th fixed load center of gravity offset.

[0043] In an optional embodiment, the step of determining the maximum allowable load mass at the i-th fixed load center of gravity offset based on any one of the second motor's equivalent output torque, the maximum torque, and the first difference and the second difference corresponding to the second motor's equivalent output torque includes:

[0044] Calculating an absolute value of a sixth difference between the second motor equivalent output torque of the second target joint and the maximum torque corresponding to the second target joint;

[0045] comparing the absolute value of the sixth difference with the termination threshold;

[0046] When the absolute value of the sixth difference is greater than the termination threshold, calculating a second product of the first difference of the second target joint and the second difference of the second target joint;

[0047] When the second product is zero or -1, the j-th end load mass is used as the maximum allowable load mass under the i-th fixed load center of gravity offset.

[0048] In a second aspect, an embodiment of the present application provides a load curve determination device, the device comprising:

[0049] Building module, used to construct the robot inverse dynamics theory model;

[0050] a determination module, configured to determine initial state parameters of each joint angle of the robot in a stationary extended state; determine target joints in the robot; and determine an initial motor equivalent output torque of each target joint based on the initial state parameters and the inverse dynamics theoretical model;

[0051] a calculation module, configured to calculate the maximum allowable load mass of the end of the robot under a fixed load center of gravity offset when the initial motor equivalent output torque of each target joint meets a preset condition;

[0052] The construction module is further configured to construct a load curve based on the fixed load center of gravity offset and a maximum allowable load mass corresponding to the fixed load center of gravity offset.

[0053] In a third aspect, an embodiment of the present application provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the load curve determination method when executing the computer program.

[0054] In a fourth aspect, an embodiment of the present application provides a readable storage medium having a computer program stored thereon, which implements the steps of the load curve determination method when executed by a processor.

[0055] This application has the following beneficial effects:

[0056] This application constructs a robot inverse dynamics theoretical model, determines the initial state parameters of each joint angle of the robot in a static extended state, determines the target joints in the robot, and determines the initial motor equivalent output torque of each target joint based on the initial state parameters and the inverse dynamics theoretical model. When the initial motor equivalent output torque of each target joint meets the preset conditions, the maximum allowable load mass of the robot's end under a fixed load center of gravity offset is calculated. Based on the fixed load center of gravity offset and the maximum allowable load mass corresponding to the fixed load center of gravity offset, a load curve is constructed, which can quickly generate a relatively accurate load curve to provide effective reference value for user selection. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0058] Figure 1 Determine a schematic diagram for a load curve in the prior art;

[0059] Figure 2 A block diagram of an electronic device provided by an embodiment of the present invention;

[0060] Figure 3 One of the flow charts of a load curve determination method provided by an embodiment of the present invention;

[0061] Figure 4 A second flow chart of a method for determining a load curve provided in an embodiment of the present invention;

[0062] Figure 5 A third flow chart of a method for determining a load curve provided by an embodiment of the present invention;

[0063] Figure 6 A fourth flow chart of a method for determining a load curve provided in an embodiment of the present invention;

[0064] Figure 7 A fifth flow chart of a method for determining a load curve provided in an embodiment of the present invention;

[0065] Figure 8 A sixth flow chart of a method for determining a load curve provided in an embodiment of the present invention;

[0066] Figure 9 FIG7 is a flow chart of a method for determining a load curve provided by an embodiment of the present invention;

[0067] Figure 10 A schematic diagram of a load curve provided by an embodiment of the present invention;

[0068] Figure 11 A schematic diagram of a load curve determination device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0069] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0070] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0071] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0072] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the product of the invention is usually placed when in use. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the present invention.

[0073] In addition, the terms "first", "second", etc., if used, are merely used to distinguish and describe, and should not be understood as indicating or implying relative importance.

[0074] It should also be noted that, in the description of this application, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0075] After extensive research, the inventors found that the current implementation process of obtaining the load curve of the collaborative robot based on the actual measurement method is very cumbersome, and it is necessary to continuously try to determine the allowable center of gravity offset under the same mass. At the same time, if the interval of the linear division of mass is large, there will be a problem of large error, which will mislead the user in selecting the model. The load curve of the collaborative robot obtained based on the theoretical calculation method presents multiple results, and the overall display effect is not intuitive enough. When calculating the lateral critical value of the load center of mass, the existing method relies on the empirical calculation formula of the maximum allowable torque and moment of inertia of the load. There is uncertainty in its accuracy and it is difficult to meet high-precision requirements. When determining the longitudinal critical value of the load center of mass, the method of trying different load center of mass positions, calculating the torque generated by each joint and comparing it with the maximum allowable torque, although it can capture the load characteristics more accurately, when the number of robot joints is large, the required iterative calculation amount increases significantly, resulting in a decrease in overall calculation efficiency.

[0076] In view of the discovery of the above problems, the present embodiment provides a load curve determination method, device and electronic equipment, which can determine the initial state parameters of each joint angle of the robot in a static extended state by constructing an inverse dynamics theoretical model of the robot, determine the target joints in the robot, and determine the initial motor equivalent output torque of each target joint based on the initial state parameters and the inverse dynamics theoretical model. When the initial motor equivalent output torque of each target joint meets the preset conditions, the maximum allowable load mass of the end of the robot under a fixed load center of gravity offset is calculated. Based on the fixed load center of gravity offset and the maximum allowable load mass corresponding to the fixed load center of gravity offset, a load curve is constructed. A relatively accurate load curve can be quickly generated to provide effective reference value for user selection. The solution provided in this embodiment is elaborated in detail below.

[0077] This embodiment provides an electronic device capable of determining a load curve. In one possible implementation, the electronic device may be a user terminal, such as, but not limited to, a server, a smartphone, a personal computer (PC), a tablet computer, a personal digital assistant (PDA), a mobile internet device (MID), etc.

[0078] Please refer to Figure 2 , Figure 2 The electronic device 100 provided in the embodiment of the present application is shown in FIG. Figure 2 More or fewer components than shown, or with Figure 1 Different configurations shown. Figure 2Each component shown in the figure can be implemented by hardware, software or a combination thereof.

[0079] The electronic device 100 includes a load curve determining device 110 , a memory 120 , and a processor 130 .

[0080] The memory 120 and the processor 130 are electrically connected to each other directly or indirectly to enable data transmission or interaction. For example, these components can be electrically connected to each other via one or more communication buses or signal lines. The load curve determination device 110 includes at least one software function module that can be stored in the memory 120 in the form of software or firmware or embedded in the operating system (OS) of the electronic device 100. The processor 130 is used to execute the executable modules stored in the memory 120, such as the software function modules and computer programs included in the load curve determination device 110.

[0081] The memory 120 may be, but is not limited to, a random access memory (RAM), a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), etc. The memory 120 is used to store a program, and the processor 130 executes the program after receiving an execution instruction.

[0082] Please refer to Figure 3 , Figure 3 For application Figure 2 FIG. 1 is a flow chart of a method for determining a load curve of an electronic device 100 . The method including each step is described in detail below.

[0083] S201: Construct a theoretical model of robot inverse dynamics.

[0084] S202: Determine the initial state parameters of each joint angle of the robot in a stationary extended state.

[0085] S203: Determine the target joint in the robot.

[0086] S204: Determine the initial motor equivalent output torque of each target joint based on the initial state parameters and the inverse dynamics theoretical model.

[0087] S205: When the initial motor equivalent output torque of each target joint meets the preset conditions, the maximum allowable load mass of the end of the robot under the fixed load center of gravity offset is calculated.

[0088] S206: Constructing a load curve based on the fixed load gravity center offset and the maximum allowable load mass corresponding to the fixed load gravity center offset.

[0089] The present application embodiment is explained using a six-degree-of-freedom collaborative robot as an example:

[0090] The inverse dynamics theoretical model of the collaborative robot is established based on the Newton-Euler method, as shown in formula (1):

[0091]

[0092] Where, is the joint angular position, angular velocity and angular acceleration; M∈R 6×6 is the inertia matrix; C∈R 6 ×6 is the centripetal and Coriolis force matrix; g∈R 6 is the gravity torque; f∈R is the friction torque; τ m ∈R 6 is the initial motor equivalent output torque; τ load ∈R 6 is the external moment of the joint caused by the end load.

[0093] Taking into account the configuration and application scenarios of the collaborative robot, the present invention uses the initial state parameters of each joint angle of the robot when the robot is in a stationary extended state, and the specific expression is shown in formula (2):

[0094]

[0095] Where q sim is the angular position of each joint, in degrees, when the robot is in the extended state; is the angular velocity of each joint, in degrees / s; is the angular acceleration of each joint, in degrees / s 2 , where A max is the maximum joint acceleration.

[0096] Determine the target joint in the robot. It should be noted that the target joint is the joint that is easy to exceed the constraint among the joints of the robot.

[0097] The initial motor equivalent output torque of each target joint is determined based on the robot inverse dynamics theoretical model and initial state parameters. The maximum torque τ allowed by the joint harmonic reducer is used for starting and stopping. gearThe target joint torques calculated by the robot's inverse dynamics theory model are compared with the constraints to obtain the maximum allowable load mass under a fixed center of gravity offset. A load curve is constructed based on the fixed load center of gravity offset and the maximum allowable load mass corresponding to the fixed load center of gravity offset.

[0098] There are many ways to determine whether the initial motor equivalent output torque of each target joint meets the preset conditions. In one implementation, Figure 4 As shown, the following steps are included:

[0099] S301: For each target joint, the initial motor equivalent output torque of the target joint is compared with the maximum torque allowed by the start and stop of the joint harmonic reducer corresponding to the target joint.

[0100] S302: When the initial motor equivalent output torque of each target joint is less than the corresponding joint harmonic reducer start-stop allowable maximum torque, determine that the initial motor equivalent output torque of each target joint meets the preset conditions.

[0101] In one example, the target joints include a first target joint, namely joint 2, and a second target joint, namely joint 4. The initial motor equivalent output torque corresponding to the first target joint is: The initial motor equivalent output torque corresponding to the second target joint is: The maximum torque allowed by the start and stop of the joint harmonic reducer corresponding to the first target joint is The maximum torque allowed by the start and stop of the joint harmonic reducer corresponding to the second target joint is

[0102] The initial motor equivalent output torque corresponding to the first target joint Does not meet the maximum torque allowed for the start and stop of the corresponding joint harmonic reducer And the initial motor equivalent output torque corresponding to the second target joint is Does not meet the maximum torque allowed for the start and stop of the corresponding joint harmonic reducer You need to check whether the dynamic parameters and constraints correspond to the current model robot.

[0103] The initial motor equivalent output torque corresponding to the first target joint Less than the maximum torque allowed for the start and stop of the corresponding joint harmonic reducer And the initial motor equivalent output torque corresponding to the second target joint is Less than the maximum torque allowed for the start and stop of the corresponding joint harmonic reducer It is determined that the initial motor equivalent output torque of each target joint meets the preset conditions.

[0104] When the initial motor equivalent output torque of each target joint meets the preset conditions, there are many ways to calculate the maximum allowable load mass of the robot end under the fixed load center of gravity offset. In one implementation, for example, Figure 5 As shown, the following steps are included:

[0105] S401: When the initial motor equivalent output torque of each target joint meets the preset conditions, the fixed load center of gravity offset table is traversed using the variable i.

[0106] The fixed load gravity center offset table includes the gravity center offsets of the fixed loads in an increasing relationship.

[0107] S402: Determine the maximum allowable load mass under the i-th fixed load center of gravity offset, use the variable j to traverse the end load mass table, and determine the maximum allowable load mass under the i-th fixed load center of gravity offset.

[0108] The terminal load mass table includes the terminal load masses in an increasing relationship.

[0109] There are many ways to determine the maximum allowable load mass under the i-th fixed load center of gravity offset, using variable j to traverse the end load mass table, and determine the maximum allowable load mass under the i-th fixed load center of gravity offset. In one implementation, for example Figure 6 As shown, the following steps are included:

[0110] S501: Determine the equivalent output torque of the first motor corresponding to the j-1th end load mass of each target joint under the i-th fixed load center of gravity offset.

[0111] S502: Determine the equivalent output torque of the second motor corresponding to the j-th end load mass of each target joint under the i-th fixed load center of gravity offset.

[0112] S503: Calculate a first difference between the equivalent output torque of the first motor and the maximum torque.

[0113] S504: Calculate a second difference between the equivalent output torque of the second motor and the maximum torque.

[0114] S505: Determine the maximum allowable load mass at the i-th fixed load center of gravity offset based on the equivalent output torque of the second motor and the maximum torque corresponding to the target joint.

[0115] S506: Determine the maximum allowable load mass under the center of gravity offset in the i-th fixed load based on the equivalent output torque of any second motor, the maximum torque, and the first difference and the second difference corresponding to the equivalent output torque of the second motor.

[0116] The process corresponding to the fixed load center of gravity offset and the end load mass increase can be expressed as:

[0117]

[0118] r offsetCOG (i) is the center of gravity offset of the i-th fixed load; m load (j|i) is the mass of the jth end load under the i-th fixed load center of gravity offset.

[0119] The terminal load mass in the terminal load mass table starts at 0 and increases by Δm. The fixed load center of gravity offset in the fixed load center of gravity offset table starts at 0 and increases by Δl.

[0120] Exemplarily, when the target joints include a first target joint, i.e., joint 2, and a second target joint, i.e., joint 4, and the i-th fixed load center of gravity offset is Δl, the variable j is used to traverse the end load mass table, starting from the first end load mass in the end load mass table. When the end load mass includes 0, Δm, 2Δm, and 3Δm, the equivalent output torque of the motor of the first target joint and the equivalent output torque of the motor of the second target joint are determined based on the robot inverse dynamics theoretical model when the end load mass is 0. When the end load mass is Δm, the equivalent output torque of the motor of the first target joint and the equivalent output torque of the motor of the second target joint are determined based on the robot inverse dynamics theoretical model when the end load is Δm. When the j-th end load mass is Δm, the j-1-th end load mass is 0. For the first target joint, under the i-th fixed load center of gravity offset, the first motor equivalent output torque corresponding to the j-1-th end load mass of the first target joint is calculated. Under the i-th fixed load center of gravity offset, the second motor equivalent output torque corresponding to the j-th end load mass of the first target joint is calculated. For the second target joint, under the i-th fixed load center of gravity offset, the first motor equivalent output torque corresponding to the j-1-th end load mass of the second target joint is calculated. Under the i-th fixed load center of gravity offset, the second motor equivalent output torque corresponding to the j-th end load mass of the second target joint is calculated.

[0121] For each target joint, the first difference between the equivalent output torque of the first motor of the first target joint and the maximum torque is calculated, the second difference between the equivalent output torque of the second motor and the maximum torque is calculated, the first difference between the equivalent output torque of the first motor of the second target joint and the maximum torque is calculated, and the second difference between the equivalent output torque of the second motor and the maximum torque is calculated.

[0122] Based on the equivalent output torque of the second motor of the first target joint, the maximum torque corresponding to the first target joint, the equivalent output torque of the second motor of the second target joint, and the maximum torque corresponding to the second target joint, the maximum allowable load mass under the i-th fixed load center of gravity offset is determined.

[0123] Or based on the equivalent output torque of the second motor of any target joint, the maximum torque of the target joint, and the first difference and second difference corresponding to the equivalent output torque of the second motor corresponding to the target joint, the maximum allowable load mass under the i-th fixed load center of gravity offset is determined.

[0124] There are many ways to determine the maximum allowable load mass under the i-th fixed load center of gravity offset based on the equivalent output torque of the second motor and the maximum torque corresponding to the target joint. In one implementation, Figure 7 As shown, the following steps are included:

[0125] S601: Compare the equivalent output torque of the second motor corresponding to the second target joint with the maximum torque corresponding to the second target joint.

[0126] S602: When the second motor equivalent output torque corresponding to the second target joint is less than the maximum torque corresponding to the second target joint, calculate the absolute value of the third difference between the second motor equivalent output torque corresponding to the first target joint and the maximum torque corresponding to the first target joint.

[0127] S603: Compare the absolute value of the third difference with the termination threshold.

[0128] S604: If the absolute value of the third difference is less than or equal to the termination threshold, the j-th end load mass is used as the maximum allowable load mass under the i-th fixed load center of gravity offset.

[0129] Exemplarily, the target joints include a first target joint, ie, joint 2, and a second target joint, ie, joint 4. The first target joint is arranged before the second target joint. 4 τ is the equivalent output torque of the second motor corresponding to the jth end load mass at the second target joint under the i-th fixed load center of gravity offset. 2 is the equivalent output torque of the second motor corresponding to the jth end load mass of the first target joint under the i-th fixed load center of gravity offset. is the maximum torque corresponding to the second target joint, is the maximum torque corresponding to the first target joint.

[0130] like when When ε is the termination threshold, the maximum allowable load mass is output.

[0131] There are multiple implementations for determining the maximum allowable load mass under the i-th fixed load center of gravity offset based on the equivalent output torque of any second motor, the maximum torque, the first difference and the second difference corresponding to the equivalent output torque of the second motor. In one implementation, Figure 8 As shown, the following steps are included:

[0132] S701: Calculate the absolute value of the fourth difference between the equivalent output torque of the second motor corresponding to the first target joint and the maximum torque corresponding to the first target joint.

[0133] S702: Compare the absolute value of the fourth difference with the termination threshold.

[0134] S703: When the absolute value of the fourth difference is greater than the termination threshold, calculate a first product of the first motor equivalent output torque of the first target joint and the second motor equivalent output torque of the first target joint.

[0135] S704: When the first product is zero or -1, the j-th end load mass is used as the maximum allowable load mass under the i-th fixed load center of gravity offset.

[0136] Δτ 2 (j-1|i) is the first difference between the first motor equivalent output torque corresponding to the first target joint under the i-th fixed load center of gravity offset and the first target joint under the j-1th end load mass and the maximum torque corresponding to the first target joint. Δτ 2 (j|i) is the first difference and the second difference between the equivalent output torque of the first motor corresponding to the first target joint under the i-th fixed load center of gravity offset and the j-th end load mass and the maximum torque corresponding to the first target joint.

[0137] like when And sign(Δτ 2 (j-1|i)×Δτ 2 When (j|i))≤0, the maximum allowable load mass is output.

[0138] There are many ways to determine the maximum allowable load mass under the i-th fixed load center of gravity offset based on the equivalent output torque of the second motor and the maximum torque corresponding to the target joint. In one implementation, Figure 9 As shown, the following steps are included:

[0139] S801: Calculate the fifth difference between the equivalent output torque of the second motor of the second target joint and the maximum torque corresponding to the second target joint.

[0140] S802: Compare the fifth difference value with the termination threshold.

[0141] S803: When the fifth difference is less than or equal to the termination threshold, the j-th end load mass is used as the maximum allowable load mass under the i-th fixed load center of gravity offset.

[0142] like Outputs the maximum permissible load mass.

[0143] Based on any second motor equivalent output torque, maximum torque, and the first difference and second difference corresponding to the second motor equivalent output torque, the implementation method for determining the maximum allowable load mass under the i-th fixed load center of gravity offset can also be: calculating the absolute value of the sixth difference between the second motor equivalent output torque of the second target joint and the maximum torque corresponding to the second target joint; comparing the absolute value of the sixth difference with the termination threshold; when the absolute value of the sixth difference is greater than the termination threshold, calculating the second product of the first difference of the second target joint and the second difference of the second target joint; when the second product is zero or the second product is -1, taking the j-th end load mass as the maximum allowable load mass under the i-th fixed load center of gravity offset.

[0144] like And sign(Δτ 4 (j-1|i)×Δτ 4 (j|i))≤0, output the maximum allowable load mass.

[0145] Δτ 4 (j-1|i) is the first difference between the equivalent output torque of the first motor corresponding to the second target joint under the i-th fixed load center of gravity offset and the maximum torque corresponding to the first target joint under the j-1th end load mass. Δτ 4 (j|i) is the first difference between the equivalent output torque of the first motor corresponding to the second target joint under the i-th fixed load center of gravity offset and the j-th end load mass and the maximum torque corresponding to the first target joint.

[0146] After determining the maximum allowable load mass corresponding to each fixed load center of gravity offset, the load curve is drawn, such as Figure 10 The figure shows a load curve diagram.

[0147] In order to make Figure 10 The load curve is relatively smooth, and the cubic Hermite polynomial interpolation method can be used to smooth it.

[0148] Second aspect: The present invention provides a method for curve correction based on load curve simulation results and combined with an actual robot, which is specifically implemented as follows:

[0149] Step 1: Based on the load curve simulation results and the actual robot, perform curve correction. Based on the load curve simulation results obtained in the first step, the load curve is corrected by attaching a corresponding load to the robot end and performing actual measurements, using the corresponding maximum allowable center of gravity offset in the simulation results as a reference based on the fixed end load mass. The fixed end load mass can be selected based on linear partitioning.

[0150] Step 2: Interpolate the load curve measured results obtained in step 1 to smooth the curve. Similarly, use the cubic Hermite polynomial interpolation method to smooth the load curve measured results.

[0151] The load curve determination method proposed by the present invention can be combined with a dynamic model to provide simulation results with physical significance, and can be corrected based on actual measurements. It is easier to implement than the existing technology of obtaining load curves based on actual measurements.

[0152] This method simulates a specific motion state and only considers the influence of two joints. Therefore, compared with other existing simulation solutions, the computational complexity is smaller and the overall algorithm logic is simpler. Furthermore, actual measurement corrections based on the simulation further ensure the accuracy of the load curve.

[0153] Please refer to Figure 11 The embodiment of the present application also provides an application Figure 2 The load curve determining device 110 of the electronic device 100 includes:

[0154] A construction module 111 is used to construct a robot inverse dynamics theoretical model;

[0155] The determination module 112 is configured to determine initial state parameters of each joint angle of the robot in a stationary extended state; determine target joints in the robot; and determine initial motor equivalent output torques of each target joint based on the initial state parameters and the inverse dynamics theoretical model.

[0156] A calculation module 113 is configured to calculate the maximum allowable load mass of the end of the robot under a fixed load center of gravity offset when the initial motor equivalent output torque of each target joint meets a preset condition;

[0157] The constructing module 111 is further configured to construct a load curve based on the fixed load gravity center offset and the maximum allowable load mass corresponding to the fixed load gravity center offset.

[0158] The present application further provides an electronic device 100, which includes a processor 130 and a memory 120. The memory 120 stores computer-executable instructions, which, when executed by the processor 130, implement the load curve determination method.

[0159] The embodiment of the present application further provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by the processor 130, the load curve determination method is implemented.

[0160] In the embodiments provided in this application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architectures, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and the module, program segment or a part of the code contains one or more executable instructions for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or can be implemented using a combination of dedicated hardware and computer instructions.

[0161] In addition, the functional modules in each embodiment of the present application can be integrated together to form an independent part, or each module can exist separately, or two or more modules can be integrated to form an independent part. If the function is implemented in the form of a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0162] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0163] The above descriptions are merely examples of various embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any modifications or substitutions that can be readily conceived by a person skilled in the art within the technical scope disclosed in the present application should be included within the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for determining a load curve, characterized in that: The method comprises: Construct a theoretical model of robot inverse dynamics; Determining initial state parameters of each joint angle of the robot when the robot is in a stationary extended state; determining a target joint in the robot; Determine the initial motor equivalent output torque of each target joint based on the initial state parameters and the inverse dynamics theoretical model; When the initial motor equivalent output torque of each target joint meets a preset condition, calculating the maximum allowable load mass of the end of the robot under a fixed load center of gravity offset; A load curve is constructed based on the fixed load center of gravity offset and the maximum allowable load mass corresponding to the fixed load center of gravity offset.

2. The method according to claim 1, characterized in that The method further comprises: For each target joint, the initial motor equivalent output torque of the target joint is compared with the maximum torque allowed by the start-stop of the joint harmonic reducer corresponding to the target joint; When the initial motor equivalent output torque of each target joint is less than the corresponding joint harmonic reducer start-stop allowable maximum torque, it is determined that the initial motor equivalent output torque of each target joint meets the preset conditions.

3. The method according to claim 1, characterized in that The step of calculating the maximum allowable load mass of the end of the robot under a fixed load center of gravity offset when the initial motor equivalent output torque of each target joint meets a preset condition comprises: When the initial motor equivalent output torque of each target joint meets a preset condition, the variable i is used to traverse the fixed load center of gravity offset table, wherein the fixed load center of gravity offset table includes each fixed load center of gravity offset in an increasing relationship; Determine the maximum allowable load mass under the i-th fixed load center of gravity offset, and use the variable j to traverse the end load mass table to determine the maximum allowable load mass under the i-th fixed load center of gravity offset, wherein the end load mass table includes each end load mass in an increasing relationship.

4. The method according to claim 3, characterized in that The step of determining the maximum allowable load mass under the i-th fixed load center of gravity offset by traversing the end load mass table using the variable j to determine the maximum allowable load mass under the i-th fixed load center of gravity offset includes: Determine the equivalent output torque of the first motor corresponding to the j-1th end load mass of each target joint under the i-th fixed load center of gravity offset; Determine the equivalent output torque of the second motor corresponding to the j-th end load mass of each target joint under the i-th fixed load center of gravity offset; Calculating a first difference between the equivalent output torque of the first motor and the maximum torque; Calculating a second difference between the equivalent output torque of the second motor and the maximum torque; Determining a maximum allowable load mass at an i-th fixed load center of gravity offset based on the equivalent output torque of the second motor and the maximum torque corresponding to the target joint; or; Based on any one of the second motor's equivalent output torque, the maximum torque, and the first difference and the second difference corresponding to the second motor's equivalent output torque, the maximum allowable load mass at the i-th fixed load center of gravity offset is determined.

5. The method according to claim 4, characterized in that The target joint includes a first target joint and a second target joint, the first target joint is arranged in front of the second target joint, and the step of determining the maximum allowable load mass under the i-th fixed load center of gravity offset based on the equivalent output torque of the second motor and the maximum torque corresponding to the target joint includes: comparing the equivalent output torque of the second motor corresponding to the second target joint with the maximum torque corresponding to the second target joint; When the second motor equivalent output torque corresponding to the second target joint is less than the maximum torque corresponding to the second target joint, calculating an absolute value of a third difference between the second motor equivalent output torque corresponding to the first target joint and the maximum torque corresponding to the first target joint; comparing the absolute value of the third difference with a termination threshold; When the absolute value of the third difference is less than or equal to the termination threshold, the j-th end load mass is used as the maximum allowable load mass under the i-th fixed load center of gravity offset.

6. The method according to claim 5, characterized in that The step of determining the maximum allowable load mass at the i-th fixed load center of gravity offset based on any one of the second motor's equivalent output torque, the maximum torque, and the first difference and the second difference corresponding to the second motor's equivalent output torque includes: Calculating an absolute value of a fourth difference between an equivalent output torque of the second motor corresponding to the first target joint and a maximum torque corresponding to the first target joint; comparing the absolute value of the fourth difference with the termination threshold; When the absolute value of the fourth difference is greater than the termination threshold, calculating a first product of the first difference of the first target joint and the second difference of the first target joint; When the first product is zero or -1, the j-th end load mass is used as the maximum allowable load mass under the i-th fixed load center of gravity offset.

7. The method according to claim 5, characterized in that The step of determining the maximum allowable load mass at the i-th fixed load center of gravity offset based on the equivalent output torque of the second motor and the maximum torque corresponding to the target joint includes: Calculating a fifth difference between the second motor equivalent output torque of the second target joint and the maximum torque corresponding to the second target joint; comparing the fifth difference value with the termination threshold; When the fifth difference is less than or equal to the termination threshold, the j-th end load mass is used as the maximum allowable load mass under the i-th fixed load center of gravity offset.

8. The method according to claim 5, characterized in that The step of determining the maximum allowable load mass at the i-th fixed load center of gravity offset based on any one of the second motor's equivalent output torque, the maximum torque, and the first difference and the second difference corresponding to the second motor's equivalent output torque includes: Calculating an absolute value of a sixth difference between the second motor equivalent output torque of the second target joint and the maximum torque corresponding to the second target joint; comparing the absolute value of the sixth difference with the termination threshold; When the absolute value of the sixth difference is greater than the termination threshold, calculating a second product of the first difference of the second target joint and the second difference of the second target joint; When the second product is zero or -1, the j-th end load mass is used as the maximum allowable load mass under the i-th fixed load center of gravity offset.

9. A load curve determination device, characterized in that: The device comprises: Building module, used to construct the theoretical model of robot inverse dynamics; a determination module, configured to determine initial state parameters of each joint angle of the robot in a stationary extended state; determine target joints in the robot; and determine an initial motor equivalent output torque of each target joint based on the initial state parameters and the inverse dynamics theoretical model; a calculation module, configured to calculate the maximum allowable load mass of the end of the robot under a fixed load center of gravity offset when the initial motor equivalent output torque of each target joint meets a preset condition; The construction module is further configured to construct a load curve based on the fixed load center of gravity offset and a maximum allowable load mass corresponding to the fixed load center of gravity offset.

10. An electronic device, characterized in that: The method comprises a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the method according to any one of claims 1 to 8 when executing the computer program.

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