Robot safety emergency stop method, device, computer device, readable storage medium and program product

Abstract

The present application relates to a robot safety emergency stop method, device, computer device, computer-readable storage medium, and computer program product. The method includes: when receiving an emergency stop signal for a robot, determining a preset spline curve of the robot and a spatio-temporal mapping expression for describing the mapping relationship between the arc length and time during the emergency stop of the robot; the unknown coefficients in the spatio-temporal mapping expression are functions of the emergency stop time and the emergency stop arc length; based on the preset spline curve and the spatio-temporal mapping expression, determining the trajectory constraint conditions of the robot; based on the inherent constraint conditions and the trajectory constraint conditions of the robot, determining the expected emergency stop time and the expected emergency stop arc length during the emergency stop of the robot; substituting the expected emergency stop time and the expected emergency stop arc length into the spatio-temporal mapping expression to determine the running trajectory during the emergency stop. Using this method can improve the safety of emergency stops.

Description

Technical Field

[0001] The present application relates to the technical field of robot control, and in particular, to a robot safety emergency stop method, device, computer device, computer-readable storage medium, and computer program product. Background Art

[0002] With the development of robot control technology, robot emergency stop technology has emerged. When an unexpected situation occurs during the operation of a robot, such as someone entering the working area or an abnormal action executed by the robot, it can ensure that the operation of the robot can be quickly stopped in an emergency, thereby protecting the safety of personnel, equipment, and the environment.

[0003] In traditional technologies, the emergency stop process generally relies on the method of motor braking. However, since a large current peak will be generated due to sudden stop of motion, the huge impact force may cause damage to the robot or its mechanical components, resulting in collisions with other equipment or people, and there is a problem of unsafe emergency stop. Summary of the Invention

[0004] Based on this, in view of the above technical problems, it is necessary to provide a robot safety emergency stop method, device, computer device, computer-readable storage medium, and computer program product that can improve the safety of emergency stop.

[0005] In a first aspect, the present application provides a robot safety emergency stop method, including:

[0006] When receiving an emergency stop signal for the robot, determining a preset spline curve of the robot and a spatio-temporal mapping expression for describing the mapping relationship between the arc length and time of the robot during the emergency stop process; the unknown coefficients in the spatio-temporal mapping expression are functions of the emergency stop time and the emergency stop arc length;

[0007] Based on the preset spline curve and the spatio-temporal mapping expression, determining the trajectory constraint conditions of the robot;

[0008] Based on the inherent constraint conditions and the trajectory constraint conditions of the robot, determining the expected emergency stop time and the expected emergency stop arc length of the robot during the emergency stop process;

[0009] Substituting the expected emergency stop time and the expected emergency stop arc length into the spatio-temporal mapping expression to determine the running trajectory during the emergency stop process.

[0010] In one embodiment, the determining the preset spline curve of the robot includes:

[0011] Obtaining the trajectory information of the robot; the trajectory information is used to characterize the initial trajectory corresponding to the robot under normal operation;

[0012] Based on the trajectory information, a preset spline curve of the robot is constructed.

[0013] In one embodiment, determining a spatiotemporal mapping expression for describing a mapping relationship between arc length and time during an emergency stop of the robot comprises:

[0014] Obtaining an initial mapping expression and an operating boundary condition corresponding to the robot during an emergency stop process; the initial mapping expression includes unknown coefficients; the operating boundary condition is characterized by an emergency stop time and an emergency stop arc length;

[0015] The unknown coefficient is solved based on the operation boundary condition, and the unknown coefficient is expressed as a function of the emergency stop time and the emergency stop arc length, so as to obtain a space-time mapping expression for describing the mapping relationship between the arc length and time during the emergency stop process of the robot.

[0016] In one embodiment, obtaining the operating boundary conditions corresponding to the robot during the emergency stop process includes:

[0017] Obtaining emergency stop status information corresponding to the robot during the emergency stop process;

[0018] Based on the emergency stop state information, a boundary condition analysis is performed on the initial mapping expression to determine the operating boundary conditions of the emergency stop process.

[0019] In one embodiment, solving the unknown coefficient based on the operating boundary conditions and expressing the unknown coefficient as a function of the emergency stop time and the emergency stop arc length includes:

[0020] Converting the initial mapping expression into a converted mapping expression that matches the functional form of the operating boundary condition;

[0021] The conversion mapping expression and the operation boundary condition are combined to express the unknown coefficient as a function of the emergency stop time and the emergency stop arc length.

[0022] In one embodiment, determining the expected emergency stop time and expected emergency stop arc length of the robot during the emergency stop process based on the inherent constraints of the robot and the trajectory constraints includes:

[0023] Obtaining a constraint set based on the inherent constraint conditions of the robot and the trajectory constraint conditions;

[0024] The constraint set is input into an optimal solver, and the output of the optimal solver is used as the expected emergency stop time and expected emergency stop arc length of the robot during the emergency stop process.

[0025] In a second aspect, the present application further provides a robot safety emergency stop device, including:

[0026] An expression acquisition module, configured to determine a preset spline curve of the robot and a spatio-temporal mapping expression for describing the mapping relationship between the arc length and time of the robot during the emergency stop when receiving an emergency stop signal for the robot; the unknown coefficients in the spatio-temporal mapping expression are functions of the emergency stop time and the emergency stop arc length;

[0027] A constraint condition calculation module, configured to determine the trajectory constraint conditions of the robot based on the preset spline curve and the spatio-temporal mapping expression;

[0028] An emergency stop data determination module, configured to determine the expected emergency stop time and the expected emergency stop arc length of the robot during the emergency stop based on the inherent constraint conditions of the robot and the trajectory constraint conditions;

[0029] An operating trajectory determination module, configured to substitute the expected emergency stop time and the expected emergency stop arc length into the spatio-temporal mapping expression to determine the operating trajectory during the emergency stop.

[0030] In a third aspect, the present application further provides a computer device. The computer device includes a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the steps of the method described above are implemented.

[0031] In a fourth aspect, the present application further provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method described above are implemented.

[0032] In a fifth aspect, the present application further provides a computer program product. The computer program product includes a computer program, and when the computer program is executed by a processor, the steps of the method described above are implemented.

[0033] The above-mentioned robot safety emergency stop method, device, computer equipment, computer-readable storage medium and computer program product, when receiving an emergency stop signal for the robot, determine the preset spline curve of the robot and the spatio-temporal mapping expression for describing the mapping relationship between the arc length and time during the emergency stop process of the robot. Among them, the unknown coefficients in the spatio-temporal mapping expression are functions of the emergency stop time and the emergency stop arc length. By taking the emergency stop time and the emergency stop arc length as functions of the unknown coefficients, this expression can accurately reflect the dynamic behavior of the robot during the emergency stop process. Based on the preset spline curve and the spatio-temporal mapping expression, determine the trajectory constraint conditions of the robot. These conditions ensure that the robot will not exceed the predetermined motion range or generate excessive acceleration during the emergency stop process, thereby ensuring the safety and stability of the emergency stop process. Finally, based on the inherent constraint conditions and trajectory constraint conditions of the robot, determine the expected emergency stop time and the expected emergency stop arc length during the emergency stop process, which helps to more accurately predict and control the emergency stop behavior of the robot. Substitute the expected emergency stop time and the expected emergency stop arc length into the spatio-temporal mapping expression to determine the running trajectory during the emergency stop process. The above method can significantly reduce the risk of the robot colliding with obstacles or personnel during the emergency stop process by precisely controlling the emergency stop trajectory and the expected emergency stop time / arc length. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments of the present application or related technologies. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0035] Figure 1 It is an application environment diagram of the robot safety emergency stop method in an embodiment;

[0036] Figure 2 It is a flowchart of the robot safety emergency stop method in an embodiment;

[0037] Figure 3 It is a flowchart of the robot safety emergency stop method in another embodiment;

[0038] Figure 4 It is a structural block diagram of the robot safety emergency stop device in an embodiment;

[0039] Figure 5 It is an internal structure diagram of the computer equipment in an embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] In order to make the objectives, technical solutions and advantages of the present application more clear and understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0041] The robot safety emergency stop method provided by the embodiment of the present application can be applied to an application environment as Figure 1 shown. Among them, the terminal 102 communicates with the server 104 through a network. The data storage system can store the data that the server 104 needs to process. The data storage system can be integrated on the server 104, or can be placed in the cloud or other network servers. Among them, the terminal 102 can be, but is not limited to, various personal computers, laptop computers, smart phones, tablet computers, Internet of Things devices and portable wearable devices. The Internet of Things devices can be smart speakers, smart TVs, smart air conditioners, smart vehicle-mounted devices, projection devices, etc. The portable wearable devices can be smart watches, smart bracelets, head-mounted devices, etc. The head-mounted device can be a virtual reality (VR) device, an augmented reality (AR) device, smart glasses, etc. The server 104 can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server providing cloud computing services. Specifically, during the process of the server 104 performing robot safety emergency stop, when receiving an emergency stop signal for the robot from the terminal 102, determine the preset spline curve of the robot and the spatio-temporal mapping expression for describing the mapping relationship between the arc length and time during the emergency stop process of the robot; the unknown coefficients in the spatio-temporal mapping expression are functions of the emergency stop time and the emergency stop arc length; based on the preset spline curve and the spatio-temporal mapping expression, determine the trajectory constraint conditions of the robot; based on the inherent constraint conditions and the trajectory constraint conditions of the robot, determine the expected emergency stop time and the expected emergency stop arc length during the emergency stop process of the robot; substitute the expected emergency stop time and the expected emergency stop arc length into the spatio-temporal mapping expression to determine the running trajectory during the emergency stop process.

[0042] In an exemplary embodiment, as Figure 2 shown, a robot safety emergency stop method is provided. Taking the method applied to the Figure 1 server 104 as an example for description, it includes the following steps S202 to step S208. Among them:

[0043] Step S202, when receiving an emergency stop signal for the robot, determine the preset spline curve of the robot and the spatio-temporal mapping expression for describing the mapping relationship between the arc length and time during the emergency stop process of the robot.

[0044] Among them, the emergency stop signal is a signal used to immediately stop the movement of the robot in case of an emergency. When this signal is triggered, the robot will quickly stop all movements and enter a safe state. A spline curve is obtained by giving a set of control points and then generating a smooth curve through these points. In this embodiment, the preset spline curve can be used to represent the pre-set running trajectory curve of the robot. The arc length of the robot generally refers to the length of the arc formed by the driving path of the robot during the movement process. The space-time mapping expression is a mapping form that mainly expresses time and space to convey a certain concept or information. In this embodiment, the space-time mapping expression refers to an expression that smoothly maps the change in time to the change in arc length. The unknown coefficient in the space-time mapping expression is a function of the emergency stop time and the emergency stop arc length. Among them, the emergency stop time is the time required for the emergency stop process, and the emergency stop arc length refers to the length of the emergency stop running trajectory corresponding to the emergency stop process.

[0045] Specifically, in the case of receiving an emergency stop signal for the robot, it indicates that an unexpected situation has occurred during the operation of the robot or someone has entered the working area. Therefore, in order to ensure the safety of the robot during the operation process, the preset spline curve of the robot can be determined first to determine the original operation situation of the robot, and the space-time mapping expression for describing the mapping relationship between the arc length and time during the emergency stop process of the robot can be determined, which is convenient for subsequent determination of the trajectory constraint conditions of the robot. Exemplarily, the process of determining the preset spline curve of the robot can be to first obtain the trajectory information of the robot and construct the preset spline curve based on this trajectory information, or directly obtain the preset spline curve of the robot.

[0046] Optionally, the process of determining the space-time mapping expression for describing the mapping relationship between the arc length and time during the emergency stop process of the robot can be to directly obtain the space-time mapping expression of the mapping relationship between the arc length and time during the emergency stop process of the robot that has been pre-set, or to obtain the initial mapping expression and the corresponding running boundary conditions of the robot during the emergency stop process, solve the unknown coefficients based on the running boundary conditions, express the unknown coefficients as a function of the emergency stop time and the emergency stop arc length, and obtain the space-time mapping expression for describing the mapping relationship between the arc length and time during the emergency stop process of the robot.

[0047] Step S204, based on the preset spline curve and the space-time mapping expression, determine the trajectory constraint conditions of the robot.

[0048] Among them, the trajectory constraint conditions are important factors that need to be considered during trajectory planning, ensuring that the trajectory can meet specific requirements or restrictions.

[0049] Specifically, the trajectory constraint conditions of the robot can be expressed by the following formula, the preset spline curve and the space-time mapping expression Substituting into the following formula, the trajectory constraint conditions of the robot can be obtained .

[0050]

[0051] where is the control point, describes the spline curve of the motion. In each time interval , describes the spatio-temporal mapping expression, describes that the two are an independent combination relationship.

[0052] Step S206: Based on the inherent constraint conditions and trajectory constraint conditions of the robot, determine the expected emergency stop time and expected emergency stop arc length of the robot during the emergency stop process.

[0053] Among them, the inherent constraint conditions, also known as performance constraints, are a kind of constraint conditions formulated according to the design performance or index requirements. In this embodiment, the inherent constraint conditions refer to the dynamic constraints of the robot and the smoothness constraints of the trajectory. The expected emergency stop time and expected emergency stop arc length refer to the time and arc length required for the emergency stop process predicted according to the above constraint conditions.

[0054] Specifically, after determining the inherent constraint conditions and trajectory constraint conditions of the robot, the emergency stop process of the robot can be predicted to determine the expected emergency stop time and expected emergency stop arc length of the robot during the emergency stop process. In some specific embodiments, the server can obtain a constraint set based on the inherent constraint conditions and trajectory constraint conditions of the robot, input the constraint set into an optimal solver, and use the output of the optimal solver as the expected emergency stop time and expected emergency stop arc length of the robot during the emergency stop process.

[0055] In some other specific embodiments, the server can also establish the dynamic equation of the robot according to the structural characteristics and motor performance of the robot, and establish the kinematic equation of the robot according to the joint configuration and transmission system characteristics of the robot. These equations describe the position and posture of the robot in the joint space and the workspace. Combining the dynamic and kinematic models, a mathematical model of the robot during the emergency stop process is established. Then, by numerically solving the dynamic equation or using an analytical method, the deceleration process of the robot under a given emergency stop torque is calculated, and according to the speed and acceleration changes during the deceleration process, the time required for the robot to decelerate from the current speed to zero is determined. According to the speed and acceleration changes of the robot during the emergency stop process and the limitations of the workspace, the arc length that the robot may travel during the emergency stop process is calculated.

[0056] Step S208: Substitute the expected emergency stop time and expected emergency stop arc length into the spatio-temporal mapping expression to determine the running trajectory during the emergency stop process.

[0057] Specifically, since the unknown coefficients in the spatio-temporal mapping expression are functions of the emergency stop time and the emergency stop arc length, substituting the specific values corresponding to the functions of the emergency stop time and the emergency stop arc length into the spatio-temporal mapping expression can determine the running trajectory during the emergency stop process.

[0058] For the above robot safety emergency stop method, when receiving an emergency stop signal for the robot, determine the preset spline curve of the robot and the spatio-temporal mapping expression used to describe the mapping relationship between the arc length and time during the emergency stop process of the robot. Among them, the unknown coefficients in the spatio-temporal mapping expression are functions of the emergency stop time and the emergency stop arc length. By taking the emergency stop time and the emergency stop arc length as functions of the unknown coefficients, this expression can accurately reflect the dynamic behavior of the robot during the emergency stop process. Based on the preset spline curve and the spatio-temporal mapping expression, determine the trajectory constraint conditions of the robot. These conditions ensure that the robot will not exceed the predetermined motion range or generate excessive acceleration during the emergency stop process, thus ensuring the safety and stability of the emergency stop process. Finally, based on the inherent constraint conditions and trajectory constraint conditions of the robot, determine the expected emergency stop time and the expected emergency stop arc length during the emergency stop process, which helps to more accurately predict and control the emergency stop behavior of the robot. Substitute the expected emergency stop time and the expected emergency stop arc length into the spatio-temporal mapping expression to determine the running trajectory during the emergency stop process. The above method can significantly reduce the risk of the robot colliding with obstacles or personnel during the emergency stop process by precisely controlling the emergency stop trajectory and the expected emergency stop time / arc length.

[0059] In an exemplary embodiment, determining the preset spline curve of the robot includes: obtaining the trajectory information of the robot; constructing the preset spline curve of the robot based on the trajectory information.

[0060] Among them, the trajectory information is used to characterize the initial trajectory corresponding to the robot under normal operating conditions.

[0061] Specifically, the server can first record the trajectory information such as the position, speed, and acceleration of the robot when performing tasks through sensors (such as position sensors, speed sensors, etc.) or the control system. Then, clean and organize the collected trajectory data, remove noise and outliers, and convert the data into a format suitable for subsequent processing and analysis. Then, according to the task requirements and the motion characteristics of the robot, select an appropriate type of spline curve, determine the parameters of the spline curve based on the collected trajectory data, and use the determined parameters to construct the equation of the spline curve.

[0062] In this embodiment, constructing the preset spline curve through the trajectory information of the robot can ensure the accuracy of determining the preset spline curve.

[0063] In an exemplary embodiment, determining a spatio-temporal mapping expression for describing the mapping relationship between arc length and time during an emergency stop of a robot includes: obtaining an initial mapping expression and the corresponding operating boundary conditions of the robot during the emergency stop; the initial mapping expression includes unknown coefficients; solving for the unknown coefficients based on the operating boundary conditions and expressing the unknown coefficients as functions of the emergency stop time and the emergency stop arc length to obtain a spatio-temporal mapping expression for describing the mapping relationship between arc length and time during the emergency stop of the robot.

[0064] Among them, the initial mapping expression refers to the spatio-temporal mapping expression in the initial state that includes unknown coefficients. The operating boundary conditions, characterized by the emergency stop time and the emergency stop arc length, refer to the operating boundary conditions that the robot needs to satisfy during the emergency stop, mainly involving how the robot system safely and effectively responds to the emergency stop instruction and ensures that it will not cause harm to the surrounding environment or personnel during the stopping process.

[0065] Specifically, as shown in the following formula, the initial mapping expression can be obtained first:

[0066]

[0067]

[0068] Among them, the parameter is the normalized time, and a, b, c, d, and e are the unknown coefficients. is the time when the emergency stop starts, is the emergency stop time.

[0069] The operating boundary conditions are as follows:

[0070]

[0071] Among them, is the emergency stop arc length. The speed of s relative to the planned trajectory will be equal to the speed of the trajectory at at the moment when the emergency stop is triggered. Therefore, to match the initial speed of the trajectory:

[0072]

[0073] So, by transposing the last two terms, we get:

[0074]

[0075] The other terms are relatively easy to understand, indicating that the acceleration condition at the initial moment is 0, and the speed acceleration at the final moment is 0. Since the amplitude of the polynomial is scaled according to the speed magnitude during the calculation, we default during the calculation, so .

[0076] Based on the The operating boundary conditions can be expressed as a, b, c, d, e as the emergency stop time. and emergency stop arc length This ensures a smooth transition from the nominal trajectory to the stop trajectory and the stop condition. This is the core of the entire construction. After sorting, we can get a polynomial like this:

[0077]

[0078] In this embodiment, the unknown coefficients in the initial mapping expression are solved according to the operating boundary conditions, and finally a space-time mapping expression is obtained to describe the mapping relationship between the arc length and time of the robot during the emergency stop process, which can ensure the accuracy of the space-time mapping expression.

[0079] In an exemplary embodiment, obtaining the operating boundary conditions corresponding to the robot during the emergency stop process includes: obtaining the emergency stop state information corresponding to the robot during the emergency stop process; performing boundary condition analysis on the initial mapping expression based on the emergency stop state information to determine the operating boundary conditions of the emergency stop process.

[0080] Among them, the emergency stop state information refers to the corresponding operation information of the robot in the emergency stop state. For example, when the robot starts to stop, the acceleration is zero, and when the emergency stop ends, the acceleration is zero; for example, when the robot ends the emergency stop, the emergency stop trajectory is the emergency stop arc length, that is, .

[0081] Specifically, in order to determine the operating boundary conditions corresponding to the robot during the emergency stop process, the emergency stop state information corresponding to the robot during the emergency stop process can be determined first, and the operating information corresponding to the robot in the emergency stop state can be determined. Then, the boundary condition analysis of the initial mapping expression is performed based on the emergency stop state information to determine the operating boundary conditions of the emergency stop process. Among them, the operating boundary conditions are as follows:

[0082]

[0083] In this example, the operating boundary conditions of the robot during the emergency stop process are determined according to the corresponding operating information when the robot is in the emergency stop state, so as to ensure the accuracy of the determination of the operating boundary conditions.

[0084] In an exemplary embodiment, the unknown coefficients are solved based on the operating boundary conditions, and the unknown coefficients are expressed as functions of the emergency stop time and the emergency stop arc length, including: converting the initial mapping expression into a conversion mapping expression that matches the functional form of the operating boundary conditions; combining the conversion mapping expression and the operating boundary conditions to express the unknown coefficients as functions of the emergency stop time and the emergency stop arc length.

[0085] The conversion mapping expression refers to the space-time mapping expression after the form conversion.

[0086] Specifically, the process of obtaining the space-time mapping expression according to the operating boundary conditions is as follows:

[0087] According to the operating boundary conditions "initial position The initial mapping expression is transformed, and the resulting transformed mapping expression is as follows (the following are all transformed mapping expressions obtained by transformation according to other operating boundary conditions, which will not be repeated):

[0088]

[0089] Initial Speed :

[0090]

[0091] Initial acceleration :

[0092]

[0093] End position :

[0094]

[0095] Substituting in the known values:

[0096]

[0097] End speed :

[0098]

[0099] Substituting in the known values:

[0100]

[0101] End acceleration :

[0102]

[0103] Substituting in the known values:

[0104]

[0105] Based on the above equations, the following simultaneous equations are solved:

[0106]

[0107] These equations can be solved by substitution or elimination to obtain the coefficients and Since we have already found , , we can finally construct the final polynomial .

[0108] In this embodiment, the initial mapping expression is first converted into a conversion mapping expression that matches the functional form of the operating boundary conditions, and then the conversion mapping expression and the operating boundary conditions are combined to express the unknown coefficients as functions of the emergency stop time and the emergency stop arc length, which can ensure the accuracy of the determination of the unknown coefficients.

[0109] In an exemplary embodiment, based on the inherent constraints and trajectory constraints of the robot, the expected emergency stop time and the expected emergency stop arc length of the robot during the emergency stop process are determined, including: obtaining a constraint set based on the inherent constraints and trajectory constraints of the robot; inputting the constraint set into an optimal solver, and using the output of the optimal solver as the expected emergency stop time and the expected emergency stop arc length of the robot during the emergency stop process.

[0110] The constraint set refers to a set of multiple constraint conditions. An optimal solver is a software tool or library used to solve mathematical optimization problems. The goal of a mathematical optimization problem is to find the optimal solution (maximum or minimum value) of an objective function under given constraints.

[0111] Specifically, through the optimal solver, the expected emergency stop time and expected emergency stop arc length of the robot during the emergency stop process can be solved based on the above constraints.

[0112] Among them, the dynamic constraints of the robot are:

[0113]

[0114] Meaning: This constraint ensures that the robot's motion follows the laws of physics. is the joint torque applied by the robot. The expression on the right describes the dynamic equation of the robot, including:

[0115] Inertia term: From the mass matrix It is formed by multiplying the acceleration term (the second derivative of the joint angle).

[0116] Coriolis and centrifugal terms: Calculations that describe the forces at a joint during movement.

[0117] Gravity term: Gravity vector describe.

[0118] Constraint Type: This constraint requires the calculated moment Must be in a valid range to ensure the physical rationality of the robot operation.

[0119] Smoothing constraint of the trajectory:

[0120] Used to evaluate the smoothness of the stopping trajectory. By restricting the L2 norm of the jerk, it ensures that the smoothness of the stopping trajectory is not lower than that of the nominal trajectory.

[0121]

[0122] Meaning: This constraint is used to ensure the smoothness of the robot's stopping trajectory. By comparing the jerk (third derivative) of the stopping trajectory with that of the nominal trajectory, the smoothness of the trajectory is controlled. Parameter: The parameter is the smoothness adjustment parameter, which affects the smoothness of the stopping trajectory relative to the nominal trajectory. A larger value means that a larger deviation is allowed, thus achieving a balance between smoothness and time efficiency. Constraint type: This constraint requires that the jerk of the stopping trajectory as a whole should not exceed a certain proportion of the jerk of the nominal trajectory, ensuring that there will be no overly drastic changes in the trajectory when stopping.

[0123] Constructing the optimization problem by integrating the objective and constraints, a set of constraints can be obtained:

[0124]

[0125] Finally, using an optimization solver to solve, the expected emergency stop time and the expected emergency stop arc length .

[0126] In this embodiment, based on the optimal solver, the set of constraints is solved to obtain the expected emergency stop time and the expected emergency stop arc length , which can ensure the minimization of the expected emergency stop time and the smoothness of the expected emergency stop arc length.

[0127] In a specific embodiment, a robot safety emergency stop method in an actual application scenario is also provided:

[0128] Specifically, the trajectory point is given by the user, and the robot usually obtains the trajectory analysis path based on a certain geometric algorithm . The goal of the algorithm is to construct the path . Among them is the time parameter, corresponding to the arc at a specific moment , corresponding to the trajectory position point at a specific moment .

[0129] At a specific moment Received an emergency stop signal. We need to determine the formula corresponding to the arc length and time such that the trajectory has the minimum motion time while satisfying the constraints .

[0130] Specific implementation process of the method:

[0131] 1. Determine the path based on the generalized spline:

[0132] Definition of the spline curve: For linearly independent spline functions . It means that the spline function is a mapping from an interval to real numbers. Here is a vector constructed by stacking the basis functions by column vectors.

[0133]

[0134] Where are the control points. Describes the preset spline curve of the motion. Within each time interval , the spline function defines the motion path on . Describes the space-time mapping expression, describes that the two are an independent combination relationship. Among them, corresponds to in the following formula.

[0135] Let be the mapping function of an arc of a certain section on the path from the motion time. Its role is to map each section of the parameter from to the interval.

[0136] 2. Define the mapping based on time and arc length :

[0137] It is necessary to construct a differential mapping to smoothly map the change in time to the change in arc length s. Since the end time and the stopping position are unknown, we need to transform the function into a function controlled by boundary conditions , and then further optimize the boundary conditions to make the overall time optimal under the constraints. This is our overall idea.

[0138] First, obtain the initial mapping expression:

[0139]

[0140]

[0141] Among them, the parameter is the time after normalization, and a, b, c, d, and e are unknown coefficients. is the time when the emergency stop starts, is the emergency stop time.

[0142] The operating boundary conditions are as follows:

[0143]

[0144] Among them, is the emergency stop arc length. The speed of s relative to the planned trajectory will be equal to the speed of the trajectory at at the moment when the emergency stop is triggered , so, to match the initial speed of the trajectory:

[0145]

[0146] So, by transposing the last two terms, we get:

[0147]

[0148] The other terms are easier to understand. It means that the acceleration condition at the initial moment is 0, and the speed and acceleration at the final moment are 0. Since the amplitude of the polynomial is scaled according to the speed magnitude during the calculation, in the calculation formula, we default to make , so there is .

[0149] Based on the obtained operating boundary conditions regarding , a, b, c, d, and e can be expressed as functions of the emergency stop time and the emergency stop arc length , which ensures the smooth transition from the nominal trajectory to the stop trajectory and the stop condition. This is the core part of the entire construction. After sorting, a polynomial like this can be obtained:

[0150]

[0151] The process of obtaining the spatio-temporal mapping expression according to the operating boundary conditions is as follows:

[0152] According to the operating boundary condition "initial position ", the initial mapping expression is transformed, and the obtained transformed mapping expression is as follows (the following are all transformed mapping expressions obtained according to other operating boundary conditions and will not be elaborated):

[0153]

[0154] Initial velocity :

[0155]

[0156] Initial acceleration :

[0157]

[0158] End position :

[0159]

[0160] Substitute the known values:

[0161]

[0162] End velocity :

[0163]

[0164] Substitute the known values:

[0165]

[0166] End acceleration :

[0167]

[0168] Substitute the known values:

[0169]

[0170] Simultaneous equations Based on the above equations, the following simultaneous equations are obtained and solved:

[0171]

[0172] These equations can be solved by the substitution method or the elimination method to obtain the coefficients and values. Since , , the final polynomial can ultimately be constructed .

[0173] 3. Determine the specific emergency stop time and the emergency stop arc length :

[0174] Dynamic constraints of the robot:

[0175]

[0176] Meaning: This constraint ensures that the movement of the robot follows the laws of physics. The left side is the joint torque exerted by the robot, and the right side expression describes the dynamic equation of the robot, including:

[0177] Inertia term: It is composed of the mass matrix multiplied by the acceleration term (the second derivative of the joint angle).

[0178] Coriolis and centrifugal terms: Calculated by and describe the forces during joint movement.

[0179] Gravity term: Described by the gravity vector

[0180] Constraint type: This constraint requires that the calculated torque must be within a certain valid range to ensure the physical rationality of the robot operation.

[0181] Smoothing constraint of the trajectory:

[0182] Used to evaluate the smoothness of the stopping trajectory. By restricting the L2 norm of the jerk, it ensures that the smoothness of the stopping trajectory is not lower than that of the nominal trajectory.

[0183]

[0184] Meaning: This constraint is used to ensure the smoothness of the robot stopping trajectory. By comparing the jerk (third derivative) of the stopping trajectory with that of the nominal trajectory, the smoothness of the trajectory is controlled. Parameter: The parameter is the smoothness adjustment parameter, which affects the smoothness of the stopping trajectory relative to the nominal trajectory. A larger value means that a larger deviation is allowed, thus achieving a balance between smoothness and time efficiency. Constraint type: This constraint requires that the jerk of the stopping trajectory as a whole should not exceed a certain proportion of the jerk of the nominal trajectory, ensuring that there will be no overly drastic changes in the trajectory when stopping.

[0185] Constructing the optimization problem by integrating the objective and constraints, a set of constraints can be obtained:

[0186]

[0187] Among them, P corresponds to in the above formula.

[0188] Finally, using the optimization solver to solve, the expected emergency stop time and the expected emergency stop arc length can be obtained.​

[0189] In a specific embodiment, Figure 3 As shown, a robot safety emergency stop method is also provided, including:

[0190] Step S301, when an emergency stop signal for the robot is received, obtaining trajectory information of the robot;

[0191] Among them, the trajectory information is used to characterize the initial trajectory corresponding to the robot under normal operation;

[0192] Step S302, constructing a preset spline curve of the robot based on the trajectory information;

[0193] Step S303, obtaining an initial mapping expression and the emergency stop state information corresponding to the robot during the emergency stop process;

[0194] Step S304, performing boundary condition analysis on the initial mapping expression based on the emergency stop state information to determine the operating boundary conditions of the emergency stop process;

[0195] Among them, the initial mapping expression includes unknown coefficients; the operating boundary conditions are characterized by the emergency stop time and emergency stop arc length;

[0196] Step S305, converting the initial mapping expression into a conversion mapping expression that matches the functional form of the operating boundary condition;

[0197] Step S306, jointly transform the mapping expression and the operating boundary conditions, express the unknown coefficient as a function of the emergency stop time and the emergency stop arc length, and obtain a spatiotemporal mapping expression for describing the mapping relationship between the arc length and time of the robot during the emergency stop process;

[0198] Among them, the unknown coefficients in the time-space mapping expression are functions of the emergency stop time and the emergency stop arc length;

[0199] Step S307, determining the trajectory constraint conditions of the robot based on the preset spline curve and the space-time mapping expression;

[0200] Step S308, obtaining a constraint set based on the inherent constraint conditions and trajectory constraint conditions of the robot;

[0201] Step S309, inputting the constraint set into the optimal solver, and using the output of the optimal solver as the expected emergency stop time and expected emergency stop arc length of the robot during the emergency stop process;

[0202] Step S310, substituting the expected emergency stop time and the expected emergency stop arc length into the time-space mapping expression to determine the running trajectory during the emergency stop process.

[0203] It should be understood that although the steps in the flowcharts involved in the above embodiments are sequentially shown according to the indications of the arrows, these steps are not necessarily executed sequentially in the order indicated by the arrows. Unless there is a clear indication in this document, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same moment, but can be executed at different moments. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or steps or stages in other steps.

[0204] Based on the same inventive concept, an embodiment of the present application further provides a robot safety emergency stop device for implementing the robot safety emergency stop method involved above. The solution provided by this device to solve the problem is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the robot safety emergency stop device provided below can refer to the limitations on the robot safety emergency stop method in the above text, and will not be repeated here.

[0205] In an exemplary embodiment, as Figure 4 shown, a robot safety emergency stop device 400 is provided, including: an expression acquisition module 402, a constraint condition calculation module 404, an emergency stop data determination module 406, and a running trajectory determination module 408, where:

[0206] The expression acquisition module 402 is configured to, when receiving an emergency stop signal for the robot, determine a preset spline curve of the robot and a spatio-temporal mapping expression for describing the mapping relationship between the arc length and time during the emergency stop process of the robot; the unknown coefficients in the spatio-temporal mapping expression are functions of the emergency stop time and the emergency stop arc length;

[0207] The constraint condition calculation module 404 is configured to determine the trajectory constraint conditions of the robot based on the preset spline curve and the spatio-temporal mapping expression;

[0208] The emergency stop data determination module 406 is configured to determine the expected emergency stop time and the expected emergency stop arc length of the robot during the emergency stop process based on the inherent constraint conditions and the trajectory constraint conditions of the robot;

[0209] The running trajectory determination module 408 is configured to substitute the expected emergency stop time and the expected emergency stop arc length into the spatio-temporal mapping expression to determine the running trajectory during the emergency stop process.

[0210] In an exemplary embodiment, the expression acquisition module 402 is configured to:

[0211] Obtaining the trajectory information of the robot; the trajectory information is used to characterize the initial trajectory corresponding to the robot under normal operation;

[0212] Based on the trajectory information, the preset spline curve of the robot is constructed.

[0213] In an exemplary embodiment, the expression acquisition module 402 includes:

[0214] The boundary condition acquisition unit is used to obtain the initial mapping expression and the corresponding operating boundary conditions of the robot during the emergency stop process; the initial mapping expression includes unknown coefficients; the operating boundary conditions are characterized by the emergency stop time and the emergency stop arc length;

[0215] The solving unit is used to solve the unknown coefficients based on the operating boundary conditions, express the unknown coefficients as functions of the emergency stop time and the emergency stop arc length, and obtain a space-time mapping expression for describing the mapping relationship between the arc length and time during the emergency stop process of the robot.

[0216] In an exemplary embodiment, the boundary condition acquisition unit is specifically used to:

[0217] Get the emergency stop status information corresponding to the robot during the emergency stop process;

[0218] Based on the emergency stop state information, the boundary condition analysis of the initial mapping expression is performed to determine the operating boundary conditions of the emergency stop process.

[0219] In an exemplary embodiment, the solving unit is specifically configured to:

[0220] Converting the initial mapping expression into a transformed mapping expression matching the functional form of the operating boundary condition;

[0221] The transformation mapping expressions and operating boundary conditions are combined to express the unknown coefficients as functions of the emergency stop time and emergency stop arc length.

[0222] In an exemplary embodiment, the emergency stop data determination module 406 is specifically configured to:

[0223] Based on the inherent constraints and trajectory constraints of the robot, a constraint set is obtained;

[0224] The constraint set is input into the optimal solver, and the output of the optimal solver is used as the expected emergency stop time and expected emergency stop arc length of the robot during the emergency stop process.

[0225] Each module in the above robot safety emergency stop device can be implemented in whole or in part by software, hardware and their combination. Each module can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to each module above.

[0226] In an exemplary embodiment, a computer device is provided. The computer device may be a terminal, and its internal structure diagram may be as shown in Figure 5 . The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit, and an input device. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface, the display unit, and the input device are connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals in a wired or wireless manner. The wireless manner can be achieved through WIFI, a mobile cellular network, near field communication (NFC), or other technologies. When the computer program is executed by the processor, it implements a robot safety emergency stop method. The display unit of the computer device is used to form a visually visible picture, which can be a display screen, a projection device, or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer covered on the display screen, or a button, a trackball, or a touchpad provided on the computer device housing, or an external keyboard, touchpad, or mouse, etc.

[0227] Those skilled in the art can understand that Figure 5 the structure shown in merely represents a block diagram of some structures related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0228] In an embodiment, a computer device is provided, including a memory and a processor. A computer program is stored in the memory, and when the processor executes the computer program, the steps of the above method are implemented.

[0229] In an embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by the processor, the steps of the above method are implemented.

[0230] In an embodiment, a computer program product is provided, including a computer program. When the computer program is executed by the processor, the steps of the above method are implemented.

[0231] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data that have been authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0232] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in this application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in this application can be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, data processing logics based on quantum computing, artificial intelligence (AI) processors, etc., without limitation.

[0233] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this application.

[0234] The above embodiments only express several implementation manners of this application. The description is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of this application. It should be noted that for those of ordinary skill in the art, without departing from the concept of this application, several deformations and improvements can still be made, and these all belong to the protection scope of this application. Therefore, the protection scope of this application should be subject to the appended claims.

Claims

1. A robot safety emergency stop method, characterized in that, The method comprises: In case of receiving an emergency stop signal for the robot, determining a preset spline curve of the robot; Obtaining an initial mapping expression and an operating boundary condition corresponding to the robot during an emergency stop process; the initial mapping expression includes unknown coefficients; the operating boundary condition is characterized by an emergency stop time and an emergency stop arc length; Solve the unknown coefficients based on the operating boundary conditions, and express the unknown coefficients as a function of the emergency stop time and the emergency stop arc length to obtain a spatio-temporal mapping expression that describes the mapping relationship between the arc length and time during the emergency stop of the robot; the unknown coefficients in the spatio-temporal mapping expression are functions of the emergency stop time and the emergency stop arc length; the spatio-temporal mapping expression is ; where is the time when the emergency stop starts; is the normalized time; Determining the trajectory constraint condition of the robot based on the preset spline curve and the space-time mapping expression; Based on the inherent constraints of the robot and the trajectory constraints, determining the expected emergency stop time and expected emergency stop arc length of the robot during the emergency stop process; the inherent constraints refer to the dynamic constraints of the robot and the smoothness constraints of the trajectory; The expected emergency stop time and the expected emergency stop arc length are substituted into the time-space mapping expression to determine the running trajectory during the emergency stop process.

2. The method according to claim 1, characterized in that Determining a preset spline curve of the robot comprises: Acquiring trajectory information of the robot; the trajectory information is used to characterize the initial trajectory corresponding to the robot under normal operation; Based on the trajectory information, a preset spline curve of the robot is constructed.

3. The method according to claim 1, characterized in that, Obtaining the operating boundary conditions corresponding to the robot during the emergency stop process, including: Obtaining emergency stop status information corresponding to the robot during the emergency stop process; Based on the emergency stop state information, a boundary condition analysis is performed on the initial mapping expression to determine the operating boundary conditions of the emergency stop process.

4. The method according to claim 1, wherein The step of solving the unknown coefficient based on the operating boundary condition and expressing the unknown coefficient as a function of the emergency stop time and the emergency stop arc length comprises: Converting the initial mapping expression into a converted mapping expression that matches the functional form of the operating boundary condition; The conversion mapping expression and the operation boundary condition are combined to express the unknown coefficient as a function of the emergency stop time and the emergency stop arc length.

5. The method according to any one of claims 1 to 4, characterized in that, The determining, based on the inherent constraints of the robot and the trajectory constraints, the expected emergency stop time and the expected emergency stop arc length of the robot during the emergency stop process comprises: Obtaining a constraint set based on the inherent constraint conditions of the robot and the trajectory constraint conditions; The constraint set is input into an optimal solver, and the output of the optimal solver is used as the expected emergency stop time and expected emergency stop arc length of the robot during the emergency stop process.

6. A robot safety emergency stop device, characterized in that, The device comprises: An expression acquisition module, used for determining a preset spline curve of the robot when an emergency stop signal for the robot is received; Obtaining an initial mapping expression and an operating boundary condition corresponding to the robot during an emergency stop process; the initial mapping expression includes unknown coefficients; the operating boundary condition is characterized by an emergency stop time and an emergency stop arc length; Solve the unknown coefficients based on the operating boundary conditions, and express the unknown coefficients as a function of the emergency stop time and the emergency stop arc length to obtain a spatio-temporal mapping expression that describes the mapping relationship between the arc length and time during the emergency stop of the robot; the unknown coefficients in the spatio-temporal mapping expression are functions of the emergency stop time and the emergency stop arc length; the spatio-temporal mapping expression is ; where is the time when the emergency stop starts; is the normalized time; A constraint condition calculation module, used for determining the trajectory constraint condition of the robot based on the preset spline curve and the space-time mapping expression; An emergency stop data determination module, configured to determine an expected emergency stop time and an expected emergency stop arc length of the robot during the emergency stop process based on the inherent constraint conditions of the robot and the trajectory constraint conditions; the inherent constraint conditions refer to the dynamic constraints of the robot and the smoothness constraints of the trajectory. A running trajectory determination module, configured to substitute the expected emergency stop time and the expected emergency stop arc length into the spatio-temporal mapping expression to determine the running trajectory during the emergency stop process.

7. The device according to claim 6, characterized in that, The expression acquisition module is configured to: Acquire the trajectory information of the robot; the trajectory information is used to characterize the initial trajectory corresponding to the robot under normal operation conditions. Construct a preset spline curve of the robot based on the trajectory information.

8. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, the steps of the method according to any one of claims 1 to 5 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, the steps of the method according to any one of claims 1 to 5 are implemented.

10. A computer program product comprising a computer program, characterized in that, When the computer program is executed by the processor, the steps of the method according to any one of claims 1 to 5 are implemented.

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