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

Abstract

The invention relates to a robot safety sudden stop method and device, computer equipment, a computer readable storage medium and a computer program product. The method comprises the steps of determining a preset spline curve of the robot and a space-time mapping expression used for describing a mapping relation between arc length and time in the sudden stop process of the robot under the condition that a sudden stop signal for the robot is received; an unknown coefficient in the space-time mapping expression is a function of sudden stop time and sudden stop arc length; determining a trajectory constraint condition of the robot based on a preset spline curve and the space-time mapping expression; based on the inherent constraint condition and the trajectory constraint condition of the robot, the expected sudden stop time and the expected sudden stop arc length of the robot in the sudden stop process are determined; and the expected sudden stop time and the expected sudden stop arc length are substituted into the space-time mapping expression, and the moving trajectory in the sudden stop process is determined. By adopting the method, the emergency stop safety can be improved.

Description

Technical Field

[0001] The present application relates to the field of robot control technology, and in particular to a robot safety emergency stop method, device, computer equipment, 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 the robot, such as someone entering the working area or an abnormal action performed by the robot, it can ensure that the robot can be stopped quickly in an emergency, thereby protecting the safety of personnel, equipment and the environment.

[0003] In traditional technology, the emergency stop process is generally based on the motor brake method. However, since the sudden stop of movement will generate a large current peak, the huge impact force caused may cause damage to the robot or the robot's mechanical parts, 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, it is necessary to provide a robot safe emergency stop method, device, computer equipment, computer readable storage medium and computer program product that can improve the safety of emergency stop in response to the above technical problems.

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

[0006] In the case of receiving an emergency stop signal for the robot, determining a preset spline curve of the robot and a space-time 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 space-time mapping expression are functions of the emergency stop time and the emergency stop arc length;

[0007] Determining the trajectory constraint condition of the robot based on the preset spline curve and the space-time mapping expression;

[0008] Determining an expected emergency stop time and an 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;

[0009] 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.

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

[0011] Acquiring 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 also provides a robot safety emergency stop device, comprising:

[0026] An expression acquisition module is used to determine a preset spline curve of the robot and a space-time mapping expression for describing the mapping relationship between the arc length and time of the robot during an emergency stop process when an emergency stop signal is received; the unknown coefficients in the space-time mapping expression are functions of the emergency stop time and the emergency stop arc length;

[0027] 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;

[0028] An emergency stop data determination module, used to determine 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;

[0029] The running trajectory determination module is used to substitute 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.

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

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

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

[0033] The above-mentioned robot safe 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 space-time mapping expression for describing the mapping relationship between the arc length and time of the robot during the emergency stop process, wherein the unknown coefficients in the space-time 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, the expression can accurately reflect the dynamic behavior of the robot during the emergency stop process. Based on the preset spline curve and the space-time mapping expression, the trajectory constraints of the robot are determined. These conditions ensure that the robot will not exceed the predetermined range of motion 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 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, which helps to more accurately predict and control the emergency stop behavior of the robot. The expected emergency stop time and the expected emergency stop arc length are substituted into the space-time 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 accurately 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 drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 A diagram showing an application environment of a robot safety emergency stop method in one embodiment;

[0036] Figure 2 A schematic diagram of a flow chart of a robot safety emergency stop method in one embodiment;

[0037] Figure 3 A schematic diagram of a flow chart of a robot safety emergency stop method in another embodiment;

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

[0039] Figure 5 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with 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 in the embodiment of the present application can be applied to Figure 1 In the application environment shown. Among them, the terminal 102 communicates with the server 104 through the 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 it can be placed on the cloud or other network servers. Among them, the terminal 102 can be, but is not limited to, various personal computers, laptops, smart phones, tablets, Internet of Things devices and portable wearable devices. The Internet of Things devices can be smart speakers, smart TVs, smart air conditioners, smart car devices, projection devices, etc. 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, a server cluster or distributed system composed of multiple physical servers, or a cloud server that provides cloud computing services. Specifically, during the process of the robot's safe emergency stop being performed by the server 104, when an emergency stop signal for the robot is received from the terminal 102, a preset spline curve of the robot and a space-time mapping expression for describing the mapping relationship between the arc length and time of the robot during the emergency stop process are determined; the unknown coefficients in the space-time mapping expression are functions of the emergency stop time and the emergency stop arc length; based on the preset spline curve and the space-time mapping expression, the trajectory constraints of the robot are determined; 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 are determined; the expected emergency stop time and the expected emergency stop arc length are substituted into the space-time mapping expression to determine the running trajectory during the emergency stop process.

[0042] In an exemplary embodiment, Figure 2 As shown, a robot safety emergency stop method is provided, which is applied to Figure 1 The server 104 in the example is used as an example to illustrate the method, which includes the following steps S202 to S208. Among them:

[0043] Step S202, when an emergency stop signal for the robot is received, determining a preset spline curve of the robot and a space-time mapping expression for describing a mapping relationship between arc length and time during an emergency stop of the robot.

[0044] Among them, the emergency stop signal is a signal used to immediately stop the movement of the robot in an emergency. When the signal is triggered, the robot will quickly stop all movements and enter a safe state. A spline curve is a given set of control points, and then a smooth curve is generated through these points. In this embodiment, the preset spline curve can be used to represent the running trajectory curve pre-set for the robot. The arc length of the robot usually refers to the length of the arc formed by the robot's driving path during the movement. 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 of time to the change of arc length. The unknown coefficients in the space-time mapping expression are functions 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, when an emergency stop signal is received for the robot, it indicates that an unexpected situation occurs during the operation of the robot, or someone enters the working area. Therefore, in order to ensure the safety of the robot's operation process, the preset spline curve of the robot can be determined first to determine the original operation of the robot, and to determine the time-space mapping expression used to describe the mapping relationship between the arc length and time of the robot during the emergency stop process, so as to facilitate the subsequent determination of the robot's trajectory constraint conditions. Exemplarily, the process of determining the preset spline curve of the robot can be to first obtain the robot's trajectory information, and construct the preset spline curve based on the trajectory information, or to 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 of the robot during an emergency stop can be to directly obtain a pre-set space-time mapping expression for the mapping relationship between the arc length and time of the robot during an emergency stop, or to obtain an initial mapping expression and the corresponding operating boundary conditions of the robot during the emergency stop, solve the unknown coefficients based on the operating 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 of the robot during the emergency stop.

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

[0048] Among them, trajectory constraints are important factors that need to be considered when planning trajectories, ensuring that the trajectories meet specific requirements or restrictions.

[0049] Specifically, the robot's trajectory constraint can be expressed by the following formula: and the space-time mapping expression Substituting into the following formula, we can get the robot's trajectory constraint conditions .

[0050]

[0051] in is the control point, It describes the spline curve of motion, in each time interval Inside, describes the space-time mapping expression, It describes that the two are an independent combination.

[0052] Step S206, 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 and trajectory constraints of the robot.

[0053] Among them, the inherent constraint condition, also known as the performance constraint, is a constraint condition formulated based on the design performance or index requirements. In this embodiment, the inherent constraint condition refers to the robot's dynamic constraint and the trajectory smoothness constraint. The expected emergency stop time and the expected emergency stop arc length refer to the time and arc length required for the emergency stop process predicted based on the above constraints.

[0054] Specifically, after determining the inherent constraints and trajectory constraints 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 constraints and trajectory constraints 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 other specific embodiments, the server can also establish the robot's dynamic equations based on the robot's structural characteristics and motor performance, and establish the robot's kinematic equations based on the robot's joint configuration and transmission system characteristics. These equations describe the robot's position and posture in the joint space and workspace, and combine the dynamic and kinematic models to establish a mathematical model of the robot during the emergency stop process. Afterwards, the robot's deceleration process under a given emergency stop torque is calculated by numerically solving the dynamic equations or using analytical methods, and the time required for the robot to decelerate from the current speed to zero is determined based on the changes in speed and acceleration during the deceleration process. The arc length that the robot may travel during the emergency stop process is calculated based on the changes in speed and acceleration of the robot during the emergency stop process and the limitations of the workspace.

[0056] Step S208, 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.

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

[0058] The above-mentioned robot safe emergency stop method, when receiving an emergency stop signal for the robot, determines the preset spline curve of the robot and the space-time mapping expression for describing the mapping relationship between the arc length and time of the robot during the emergency stop process, wherein the unknown coefficients in the space-time 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, the expression can accurately reflect the dynamic behavior of the robot during the emergency stop process. Based on the preset spline curve and the space-time mapping expression, the trajectory constraints of the robot are determined. These conditions ensure that the robot will not exceed the predetermined range of motion 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 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, which helps to more accurately predict and control the emergency stop behavior of the robot. The expected emergency stop time and the expected emergency stop arc length are substituted into the space-time 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 accurately controlling the emergency stop trajectory and the expected emergency stop time / arc length.

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

[0060] The trajectory information is used to characterize the initial trajectory of the robot under normal operation.

[0061] Specifically, the server can first record the robot's position, speed, acceleration and other trajectory information when performing a task through sensors (such as position sensors, speed sensors, etc.) or a control system, and 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 robot's motion characteristics, select the appropriate spline curve type, 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, the preset spline curve is constructed by using the trajectory information of the robot, so that the accuracy of the preset spline curve can be ensured.

[0063] In an exemplary embodiment, a space-time mapping expression for describing the mapping relationship between the arc length and time of the robot during an emergency stop is determined, including: 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 the unknown coefficients based on the operating boundary conditions, expressing the unknown coefficients as a function of the emergency stop time and the emergency stop arc length, and obtaining a space-time mapping expression for describing the mapping relationship between the arc length and time of the robot during the emergency stop.

[0064] The initial mapping expression refers to the space-time mapping expression under the initial state, including unknown coefficients. The operating boundary conditions, represented by the emergency stop time and the emergency stop arc length, refer to the operating boundary conditions that the robot must meet during the emergency stop process. They mainly involve how the robot system responds to the emergency stop command safely and effectively, and ensures that no harm is caused to the surrounding environment or personnel during the stop process.

[0065] Specifically, as shown below, you can first obtain the initial mapping expression:

[0066]

[0067]

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

[0069] The operating boundary conditions are as follows:

[0070]

[0071] in, is the arc length of the emergency stop. The velocity of s relative to the planned trajectory will be equal to the trajectory at the time of triggering the emergency stop. Speed , so, to match the initial velocity of the trajectory:

[0072]

[0073] So the last two terms are transposed to get:

[0074]

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

[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] Smoothness constraints on trajectories:

[0120] It is used to evaluate the smoothness of the stop trajectory and ensure that the smoothness of the stop trajectory is not less than the smoothness of the nominal trajectory by limiting the L2 norm of the jerk.

[0121]

[0122] Significance: This constraint is used to ensure the smoothness of the robot's stopping trajectory. The smoothness of the trajectory is controlled by comparing the jerk (third-order derivative) of the stopping trajectory with the jerk of the nominal trajectory. Parameters: Parameters is a smoothness adjustment parameter that affects the smoothness of the stop trajectory relative to the nominal trajectory. A value of 0 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 stop trajectory should not exceed a certain proportion of the jerk of the nominal trajectory as a whole, ensuring that the trajectory does not change too drastically when stopping.

[0123] Constructing an optimization problem and integrating the objective and constraints can result in a constraint set:

[0124]

[0125] Finally, the optimization solver is used to solve the expected emergency stop time that meets the constraints. and expected emergency stop arc length .

[0126] In this embodiment, the constraint set is solved based on the optimal solver to obtain the expected emergency stop time that satisfies the constraints. and 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 It is given by the user. The robot usually obtains the trajectory analysis path based on a certain geometric algorithm. The goal of the algorithm is to construct a path .in is the time parameter, corresponding to the arc at a specific time , corresponding to the trajectory position point at a specific time .

[0129] At a specific moment An emergency stop signal is received. We need to determine the formula corresponding to arc length and time , so that the trajectory has the minimum movement time while satisfying the constraints .

[0130] The specific implementation process of the method:

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

[0132] Spline definition: for Linearly independent spline functions . It means that the spline function is a mapping from an interval to real numbers. Here is by taking the basis function A vector constructed by stacking column vectors.

[0133]

[0134] in It is the control point. It describes the preset spline curve of the motion, in each time interval Internal spline function Defined in The motion path on the describes the space-time mapping expression, It describes that the two are an independent combination. With the following formula correspond.

[0135] set up A segment on the path from The mapping function of the arc of motion time is to transform each parameter from Map to In the interval.

[0136] 2. Time-based and arc length Defining the Mapping :

[0137] We need 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, get the initial mapping expression:

[0139]

[0140]

[0141] Among them, the parameters is the normalized time, and a, b, c, d, and e are the unknown coefficients. is the time when the emergency stop starts, The emergency stop time.

[0142] The operating boundary conditions are as follows:

[0143]

[0144] in, is the arc length of the emergency stop. The velocity of s relative to the planned trajectory will be equal to the trajectory at the time of triggering the emergency stop. Speed , so, to match the initial velocity of the trajectory:

[0145]

[0146] So the last two terms are transposed to get:

[0147]

[0148] The other items are easy to understand, indicating that the acceleration condition at the initial moment is 0. The velocity acceleration at the final moment is 0. Since the amplitude of the polynomial is scaled according to the velocity during calculation, we default to , so there is .

[0149] 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:

[0150]

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

[0152] 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):

[0153]

[0154] Initial Speed :

[0155]

[0156] Initial acceleration :

[0157]

[0158] End position :

[0159]

[0160] Substituting in the known values:

[0161]

[0162] End speed :

[0163]

[0164] Substituting in the known values:

[0165]

[0166] End acceleration :

[0167]

[0168] Substituting in the known values:

[0169]

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

[0171]

[0172] 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 .

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

[0174] Dynamic constraints of the robot:

[0175]

[0176] 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:

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

[0178] Coriolis and centrifugal terms: Calculations that describe the forces at a joint during movement.

[0179] Gravity term: Gravity vector describe.

[0180] Constraint Type: This constraint requires the calculated moment Must be in a valid range to ensure the physical rationality of the robot's operation.

[0181] Smoothness constraints on trajectories:

[0182] It is used to evaluate the smoothness of the stop trajectory and ensure that the smoothness of the stop trajectory is not less than the smoothness of the nominal trajectory by limiting the L2 norm of the jerk.

[0183]

[0184] Significance: This constraint is used to ensure the smoothness of the robot's stopping trajectory. The smoothness of the trajectory is controlled by comparing the jerk (third-order derivative) of the stopping trajectory with the jerk of the nominal trajectory. Parameters: Parameters is a smoothness adjustment parameter that affects the smoothness of the stop trajectory relative to the nominal trajectory. A value of 0 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 stop trajectory should not exceed a certain proportion of the jerk of the nominal trajectory as a whole, ensuring that the trajectory does not change too drastically when stopping.

[0185] Constructing an optimization problem and integrating the objective and constraints can result in a constraint set:

[0186]

[0187] Among them, P corresponds to the .

[0188] Finally, the optimization solver is used to solve the expected emergency stop time that meets the constraints. and expected emergency stop arc length .

[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 displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps is not strictly limited in order, 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, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0204] Based on the same inventive concept, the embodiment of the present application also provides a robot safety emergency stop device for implementing the robot safety emergency stop method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more robot safety emergency stop device embodiments provided below can refer to the limitations of the robot safety emergency stop method above, and will not be repeated here.

[0205] In an exemplary embodiment, Figure 4 As shown, a robot safety emergency stop device 400 is provided, comprising: 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, wherein:

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

[0207] The constraint condition calculation module 404 is used to determine the trajectory constraint condition of the robot based on the preset spline curve and the time-space mapping expression;

[0208] An emergency stop data determination module 406, for determining an expected emergency stop time and an expected emergency stop arc length of the robot during an emergency stop process based on inherent constraints and trajectory constraints of the robot;

[0209] The running trajectory determination module 408 is used to substitute 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.

[0210] In an exemplary embodiment, the expression acquisition module 402 is used 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 FIG. Figure 5 As shown. The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit and an input device. 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. 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 the external device. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be realized through WIFI, a mobile cellular network, near field communication (NFC) or other technologies. When the computer program is executed by the processor, a robot safety emergency stop method is realized. 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, and the input device of the computer device can be a touch layer covering the display screen, or a button, trackball or touchpad set on the computer device shell, or an external keyboard, touchpad or mouse.

[0227] Those skilled in the art will understand that Figure 5 The structure shown in the figure is only a block diagram of a part of the structure 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 certain components, or have a different arrangement of components.

[0228] In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps of the above method when executing the computer program.

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

[0230] In one embodiment, a computer program product is provided, comprising a computer program, which implements the steps of the above method when executed by a processor.

[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 used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0232] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be completed by instructing the relevant hardware through a computer program, and 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-mentioned methods. Among them, any reference to the 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), magnetic 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. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0233] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, 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, they should be considered to be within the scope of this application.

[0234] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A robot safety emergency stop method, characterized in that: The method comprises: In the case of receiving an emergency stop signal for the robot, determining a preset spline curve of the robot and a space-time 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 space-time mapping expression are functions of the emergency stop time and the emergency stop arc length; Determining the trajectory constraint condition of the robot based on the preset spline curve and the space-time mapping expression; Determining an expected emergency stop time and an 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; 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 the preset spline curve of the robot includes: 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 The determining of a spatiotemporal mapping expression for describing a mapping relationship between arc length and time during an emergency stop of the robot comprises: 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; 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.

4. The method according to claim 3, 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.

5. The method according to claim 3, characterized in that: 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.

6. The method according to any one of claims 1 to 5, 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.

7. A robot safety emergency stop device, characterized in that: The device comprises: An expression acquisition module is used to determine a preset spline curve of the robot and a space-time mapping expression for describing the mapping relationship between the arc length and time of the robot during an emergency stop process when an emergency stop signal is received; the unknown coefficients in the space-time mapping expression are functions of the emergency stop time and the emergency stop arc length; 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, used to determine 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; The running trajectory determination module is used to substitute 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.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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