Torque cut-off module, torque cut-off method, safety control module, and robot

Abstract

The present application relates to the technical field of safety control. Disclosed are a torque cut-off module, an electric motor torque cut-off method, a safety control module, and a robot. The torque cut-off module comprises: a deceleration monitoring module, which receives the actual speed of a moving member in a deceleration stage, wherein the deceleration monitoring module outputs a cut-off signal when the actual speed is greater than a safety speed, and the deceleration monitoring module outputs the cut-off signal when the actual speed is less than or equal to the safety speed and a deceleration duration reaches a safety deceleration duration; and an output module, which is connected to the deceleration monitoring module, and outputs the cut-off signal output by the deceleration monitoring module. In this way, the reliability of control over torque cut-off can be improved, and the damage to an electric motor caused by an emergency stop of the electric motor can be reduced.

Description

Torque-off module, torque-off method, safety control module and robot

[0001] This application claims priority to the Chinese patent application No. 2024108324623, filed on June 26, 2024, and entitled "Torque-off module, torque-off method, safety control module and robot", which is incorporated by reference in its entirety.

TECHNICAL FIELD

[0002] The present application relates to the technical field of safety control, in particular to a torque-off module, a motor torque-off method, a safety control module and a robot.

BACKGROUND

[0003] With the rapid development of robot technology, more and more robots are applied and popularized in the industrial field and service field, and the opportunities for robots to coexist with humans in the same work environment and interact with humans are increasing. In certain situations, in order to avoid the danger of the robot itself, such as colliding with obstacles, or the danger of the robot to humans, such as colliding with the human body, after the robot detects a dangerous situation through contact and non-contact detection, or after the human presses the emergency stop button, the safety controller can cut off the power supply of the motor of the robot, or even trigger the motor brake action, so as to make the robot stop urgently.

[0004] Although the above braking method can improve the safety of the robot, frequent power cut-off and brake action triggering in the motion state of the robot can cause damage to the robot components. Therefore, a method of braking and decelerating first and then stopping and braking can be used. However, during the braking and deceleration process of the robot, if the drive circuit of the motor or the like is abnormal, it will often lead to the danger of the motor braking not in time or the braking distance being too long.

SUMMARY

[0005] The present application provides a torque-off module, a motor torque-off method, a safety control module and a robot to solve the above problems in the prior art.

[0006] The first aspect of the present application provides a torque-off module, which comprises: a deceleration monitoring module receiving an actual speed of a moving part in a deceleration stage; the deceleration monitoring module outputs a shutdown signal when the actual speed is greater than a safety speed; the deceleration monitoring module outputs the shutdown signal when the actual speed is less than or equal to the safety speed and the deceleration time reaches a safety deceleration time; and an output module connected with the deceleration monitoring module, which outputs the shutdown signal output by the deceleration monitoring module.

[0007] In some embodiments, the deceleration monitoring module generates a safe deceleration curve based on the first starting speed of the deceleration stage and the safe deceleration time length, and obtains the safe speed based on the safe deceleration curve; wherein the safe speed of the safe deceleration curve decreases linearly with a preset slope, and the second starting speed of the safe deceleration curve is greater than the first starting speed.

[0008] In some embodiments, the deceleration monitoring module comprises: a safe speed generation module that receives the deceleration signal and starts timing, and obtains and outputs the safe speed; a comparison module connected with the safe speed generation module and the output module respectively, the comparison module outputs the shutdown signal when the actual speed is greater than the safe speed; the comparison module outputs the shutdown signal when the actual speed is less than or equal to the safe speed and the deceleration time length reaches the safe deceleration time length.

[0009] In some embodiments, the torque shutdown module further comprises: a latch module connected with the deceleration monitoring module and the output module respectively, the latch module receives the shutdown signal from the deceleration monitoring module and latches the shutdown signal, so that the output module continuously outputs the shutdown signal.

[0010] In some embodiments, the torque shutdown module comprises: two deceleration monitoring modules and two output modules, each deceleration monitoring module is connected with the two output modules; each output module outputs the shutdown signals output by the two deceleration monitoring modules, so that the motor of the moving part executes torque shutdown based on any shutdown signal.

[0011] In some embodiments, the output module comprises: a logic gate circuit or a buffer.

[0012] In some embodiments, the torque shutdown module further comprises: a signal acquisition module connected with the deceleration monitoring module, for acquiring the actual speed of the moving part.

[0013] The second aspect of the present application provides a motor torque shutdown method, comprising: receiving the actual speed of the moving part in the deceleration stage; outputting the shutdown signal in response to the actual speed being greater than the safe speed; obtaining the deceleration time length of the moving part in response to the actual speed being less than or equal to the safe speed, and outputting the shutdown signal when the deceleration time length reaches the safe deceleration time length.

[0014] The third aspect of the present application provides a safety control module, the safety control module comprises an instruction generation module and the above-mentioned torque shutdown module, the instruction generation module is connected with the torque shutdown module, and is used for outputting the deceleration signal to the torque shutdown module; the output end of the torque shutdown module is connected with the motor, and is used for outputting the shutdown signal to the motor.

[0015] The fourth aspect of the application provides a robot, comprising: a main body; a motor arranged on the main body; and a safety control module arranged on the main body and connected to the motor, wherein the safety control module controls torque shutdown of the motor by outputting a shutdown signal.

[0016] Compared with the prior art, the torque shutdown module provided by the application is provided with a deceleration monitoring module, which can monitor the actual speed of the moving part in the deceleration stage and output a shutdown signal when the actual speed is greater than the safety speed, so that the moving part outputs a shutdown signal when the actual speed in the deceleration stage exceeds the safety speed, controls the motor of the moving part to perform torque shutdown, and prevents the actual speed of the moving part from exceeding the safety speed, thereby improving the problem of brake delay or excessive brake distance caused by abnormal deceleration in the deceleration process, and thus improving the reliability of torque shutdown control. Furthermore, the torque shutdown signal is output when the actual speed is less than or equal to the safety speed and the deceleration time in the deceleration stage reaches the safety deceleration time, so that the moving part can decelerate within the safety speed range and the deceleration time is within the safety deceleration time, and the damage caused by the motor emergency stop to the motor can be reduced.

[0017] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory, rather than limiting the application. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort.

[0019] FIG. 1 is a structural schematic diagram of an embodiment of the torque shutdown module of the application;

[0020] FIG. 2 is a schematic diagram of the safety deceleration curve of the deceleration monitoring module of the application and the speed change curve of normal deceleration of the robot;

[0021] FIG. 3 is a schematic diagram of the safety deceleration curve of the deceleration monitoring module and the speed change curve of abnormal deceleration of the robot;

[0022] FIG. 4 is a schematic diagram of the safety deceleration curve and the speed change curve of the robot in the case of SS1-t;

[0023] FIG. 5 is another schematic diagram of the safety deceleration curve and the speed change curve of the robot in the case of SS1-t;

[0024] FIG. 6 is a schematic diagram of the safety deceleration curve of the deceleration monitoring module, the speed change curve of abnormal deceleration of the robot, and the timing of the shutdown signal.

[0025] Fig. 7 is a schematic diagram of a safety deceleration curve of the deceleration monitoring module, a speed change curve of normal deceleration of the robot, and a timing of the shutdown signal of the robot;

[0026] Fig. 8 is a schematic diagram of a circuit structure of an embodiment of the safety speed generation module;

[0027] Fig. 9 is a schematic diagram of another embodiment of the torque shutdown module;

[0028] Fig. 10 is a schematic diagram of still another embodiment of the torque shutdown module;

[0029] Fig. 11 is a schematic diagram of an embodiment of the motor torque shutdown method;

[0030] Fig. 12 is a schematic diagram of an embodiment of the safety control module;

[0031] Fig. 13 is a schematic diagram of an embodiment of the robot.

DETAILED DESCRIPTION

[0032] To make the skilled in the art better understand the technical solutions of the present application, the torque shutdown module, method, safety control module, and robot provided by the present application are described in further detail below in conjunction with the accompanying drawings and specific embodiments. It can be understood that the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by the skilled in the art without making creative efforts fall within the scope of protection of the present application.

[0033] The terms "first", "second", and the like in the present application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but can optionally include steps or units not listed, or can optionally include other steps or units inherent to the process, method, product, or device.

[0034] The present application provides a torque shutdown module, which can be used for a moving part such as a robot. The robot will be taken as an example for introduction. The robot can include a mobile robot, a mechanical arm, etc.

[0035] The torque-off module provided in the application can solve the problem that the drive circuit of the motor and the like of the robot in the braking deceleration process of the robot abnormally occurs to cause the motor to brake not timely or the braking distance to be too long. In particular, the motor referred to herein can be a motor that drives the whole robot to move, rotate and the like, or a motor that drives one or some components of the robot to move, rotate and the like; the safety torque-off control of the robot is realized through the torque-off module.

[0036] The output end of the torque-off module of the application is connected to the motor (the drive circuit of the motor) of the robot, and the torque-off signal output by the torque-off module controls the motor to perform torque-off. Specifically, please refer to FIG. 1, which is a structural schematic diagram of an embodiment of the torque-off module of the application. As shown in FIG. 1, the torque-off module of the embodiment includes a deceleration monitoring module 10 and an output module 20; wherein the deceleration monitoring module 10 receives the actual speed of the moving part in the deceleration stage; the deceleration monitoring module 10 outputs the shutdown signal when the actual speed is greater than the safety speed; the deceleration monitoring module 10 outputs the shutdown signal when the actual speed is less than or equal to the safety speed and the deceleration time length reaches the safety deceleration time length; the output module 20 is connected with the deceleration monitoring module 10 to output the shutdown signal output by the deceleration monitoring module 10.

[0037] Wherein, the controller or safety peripheral of the robot and the like controls the motor to decelerate when the robot needs to be stopped safely, so that the robot enters the deceleration stage, and a deceleration signal is also generated to the deceleration monitoring module 10, for example, the deceleration signal can include the enable signal (or stop signal) SFO of the controller to the motor. The deceleration monitoring module 10 receives the deceleration signal and starts timing, that is, the deceleration monitoring module 10 starts timing when the robot enters the deceleration stage to obtain the deceleration time length, and obtains the actual speed of the robot in the deceleration stage to monitor the speed of the robot in the deceleration stage, and outputs the shutdown signal when the actual speed of the robot exceeds the safety speed, and outputs the shutdown signal when the actual speed does not exceed the safety speed and the deceleration time length, that is, the deceleration timing time length, reaches the safety deceleration time length, to realize the safety deceleration and safety shutdown of the robot.

[0038] Wherein, the output module 20 is also connected with the motor of the robot to output the shutdown signal to the motor to make the motor perform torque-off. It can be understood that the output module 20 can output the shutdown signal to the motor in almost no delay, and make the motor perform torque-off in time to improve the safety.

[0039] Wherein, the speed of the moving part can include the rotating speed of the motor, the movement speed of the moving part or the movement speed of part of the components of the moving part. The following embodiments of the application will be introduced by taking the rotating speed of the motor as an example.

[0040] The torque off module of the embodiment is provided with a deceleration monitoring module 10, which can monitor the actual speed of the moving part in the deceleration stage and output a shutdown signal when the actual speed is greater than the safe speed, so that the moving part outputs a shutdown signal when the actual speed in the deceleration stage exceeds the safe speed, to control the motor of the moving part to execute torque off, so that the actual speed of the moving part will not exceed the safe speed, thereby improving the problem of brake not timely or brake distance too long caused by abnormal deceleration in the deceleration process, and thus improving the reliability of torque off control. Further, the torque off signal is output when the actual speed is less than or equal to the safe speed and the deceleration time in the deceleration stage reaches the safe deceleration time, which not only enables the moving part to decelerate within the safe speed range and enables the deceleration time to be within the safe deceleration time, but also reduces the damage caused by the motor emergency stop to the motor.

[0041] The shutdown signal includes a safe torque off (STO) signal.

[0042] In the motor control of the robot, in order to realize the safe stop of the robot, it is necessary to brake, decelerate, stop and engage the brake. In some embodiments, in order to improve the stability of the robot in the deceleration stage, the robot can be controlled to uniformly decelerate.

[0043] Optionally, the deceleration monitoring module 10 of the embodiment can also generate a safe deceleration curve based on the first starting speed of the deceleration stage and the safe deceleration time, and obtain the safe speed based on the safe deceleration curve; wherein the safe speed of the safe deceleration curve decreases linearly with a preset slope, and the second starting speed of the safe deceleration curve is greater than the first starting speed.

[0044] Wherein, the preset slope is the speed change rate of the first starting speed within the safe deceleration time, that is, the speed change rate of the first starting speed decreasing to zero within the safe deceleration time.

[0045] In the embodiment, the safe speed uniformly decreases in the uniform deceleration stage of the robot, which can make the safe speed and the actual speed more matched, and facilitate better overspeed monitoring of the actual speed; and the second starting speed of the safe speed is greater than the first starting speed, which can facilitate normal deceleration of the robot.

[0046] For example, as shown in FIG. 2, FIG. 2 is a schematic diagram of the safe deceleration curve of the deceleration monitoring module of the application and the speed change curve of the normal deceleration of the robot. Wherein, the actual speed curve Speed (which can be understood as the voltage curve corresponding to the actual speed) of the robot is the solid line shown in FIG. 2, and the safe speed curve Ramp (which can be understood as the voltage curve corresponding to the safe speed) is the dashed line shown in FIG. 2; the robot enters the deceleration stage at t0, uniformly decelerates, and then enters the safe deceleration stage at t norThe displacement of the robot in the deceleration phase is the integral of the speed, that is, the area S of the shaded part in the figure nor The starting speed of the safety speed curve Ramp in the deceleration phase, that is, the second starting speed, is slightly greater than the speed of the robot at t0, that is, the first starting speed. The safety speed is decelerated to 0 at t1 corresponding to the safety deceleration time.

[0047] The deceleration monitoring module 10 obtains the actual speed of the robot in real time or periodically, and the safety speed corresponding to the actual speed acquisition time. In the application scenario shown in FIG. 2, the robot normally decelerates, and the actual speed is always less than the safety speed. The deceleration monitoring module 10 outputs the shutdown signal at t1 corresponding to the safety deceleration time.

[0048] Optionally, the safety speed curve of the present application not only includes the safety deceleration curve, but also includes a first safety speed curve and an actual speed curve corresponding to at least part of the motion period before the deceleration phase. The first safety speed curve can constrain the safety motion of the robot before entering the deceleration phase, and the deceleration monitoring module 10 can also monitor the motion before the deceleration phase.

[0049] In another application scenario, as shown in FIG. 3, FIG. 3 is a schematic diagram of the safety deceleration curve of the deceleration monitoring module and the speed change curve of the abnormal deceleration of the robot. Abnormal deceleration means that the robot does not timely decelerate as expected. The robot starts to decelerate at t fail The robot is decelerated to 0 at t fail t1>t nor The displacement of the robot in the deceleration phase is the integral of the speed, that is, the area S of the shaded part in the figure fail , and S fail >S nor , that is, the braking distance is too long, which is prone to danger.

[0050] To solve the problems in the embodiment of FIG. 3, in the related art, a safety stop standard is set, for example, a safety stop condition SS1-tcase. SS1 is Safe Stop 1, that is, safety stop 1, which is specified in IEC 61800-5-2. SS1-t is a kind of SS1, that is, the deceleration time of the deceleration phase reaches a preset time t1, that is, the safety deceleration time, and the STO function is immediately started, and the torque output of the motor is forcibly cut off to make the motor stop as soon as possible.

[0051] As shown in FIG. 4, FIG. 4 is a schematic diagram of the safety deceleration curve and the speed change curve of the robot in the SS1-t condition. The robot starts to decelerate at t SS1-tThe time to decelerate to 0, since SS1-t monitors the braking time, to some extent solves the above abnormal deceleration problem, and improves the safety of the robot. However, the inventors of the present application found that SS1-t is powerless to abnormality in the deceleration phase (for example, insufficient deceleration), that is, the speed between t0 time and t1 time in FIG. 4 is not monitored, which can cause the braking distance (i.e., the shaded area S SS1-t ) to be too long.

[0052] For example, as shown in FIG. 5, which is another schematic diagram of the safety deceleration curve and the speed change curve of the robot in the case of SS1-t. FIG. 5 shows an extreme case in which SS1-t is powerless to abnormality in the deceleration phase. After t0 time, the motor should decelerate, but (due to fault abnormality, etc.) does not decelerate and still runs at the original speed; after t1 time, SS1-t immediately starts the STO function to make the motor stop as soon as possible, but the braking distance (i.e., the shaded area S SS1-t ) at this time is obviously much higher than the normal braking distance, that is, the shaded area S nor , resulting in too long braking distance of the robot and lower safety of the robot.

[0053] Therefore, the deceleration monitoring module 10 of the present embodiment outputs a shutdown signal to control the motor to perform torque shutdown at t1 time, that is, when the actual speed is greater than the safety speed at the corresponding time.

[0054] As shown in FIG. 6, which is a schematic diagram of the safety deceleration curve, the speed change curve of the robot abnormal deceleration, and the timing of the shutdown signal of the deceleration monitoring module of the present application. The present embodiment proposes another deceleration Safe Stop 1, that is, SS1-r. In the deceleration phase, if the actual speed of the robot exceeds the safety speed, such as at t trigger time, the actual speed corresponding to the actual speed curve Speed > the safety speed corresponding to the safety speed curve Ramp, SS1-r starts the STO function to forcibly cut off the torque output of the motor. After that, the STO function is always kept to make the motor decelerate as soon as possible until the motor decelerates to 0 at t SS1-r time.

[0055] Therefore, SS1-r of the present embodiment can effectively monitor the speed abnormality (for example, insufficient deceleration) in the deceleration phase of the robot, that is, the actual speed between t0 time and t1 time in FIG. 6 is monitored, and the braking distance (i.e., the shaded area S SS1-r ) is obviously shorter than the braking distance (i.e., the shaded area S SS1-t ) in FIGS. 4 and 5.

[0056] Further, as shown in FIG. 7, FIG. 7 is a schematic diagram of a safety deceleration curve of the deceleration monitoring module of the application, a speed change curve of normal deceleration of the robot, and a timing of the shutdown signal. If the robot decelerates normally, the actual speed is always less than the safety speed, and the SS1-r starts the STO function at the t1 moment corresponding to the safety deceleration time length, so as to keep the motor in the torque output cut-off state.

[0057] Optionally, the deceleration monitoring module 10 of the embodiment comprises a safety speed generation module 11 and a comparison module 12; the safety speed generation module 11 receives a deceleration signal and starts timing, and acquires and outputs a safety speed; the comparison module 12 is connected with the safety speed generation module 11 and the output module 20 respectively, and outputs a shutdown signal when the actual speed is greater than the safety speed; the comparison module 12 outputs a shutdown signal when the actual speed is less than or equal to the safety speed and the timing time length reaches the safety deceleration time length.

[0058] Optionally, the comparison module 12 can receive the actual speed of the moving part from a speed detection part, such as an encoder, and compare the actual speed with the safety speed.

[0059] Optionally, the comparison module 12 outputs a shutdown signal, which includes that the comparison module 12 outputs the deceleration signal received by the safety speed generation module 11 as a shutdown signal, or generates and outputs a shutdown signal.

[0060] The embodiment utilizes the safety speed generation module 11 to receive a shutdown signal, an actual speed, timing, and output a safety speed, and compares the actual speed with the safety speed through the comparison module 12 and outputs a shutdown signal based on the comparison result, which not only has a simple structure, but also can separate the comparison processing from other processing, and can improve the accuracy of deceleration monitoring.

[0061] Optionally, the safety speed generation module 11 can generate a safety deceleration curve based on the first starting speed of the deceleration stage and the safety deceleration time length, and acquire the safety speed corresponding to the actual speed from the safety deceleration curve.

[0062] In other embodiments, the deceleration monitoring module can also be implemented by other circuit structures, modules or integrated chips which can realize the above-mentioned speed monitoring.

[0063] Optionally, the deceleration signal of the embodiment comprises a low-level signal, the shutdown signal comprises a low-level signal, and the comparison module 12 comprises a comparator, the comparator is connected with the safety speed generation module 11 and is used for receiving an actual speed, the comparator outputs a low-level signal when the actual speed is greater than the safety speed, and outputs a low-level signal when the actual speed is less than or equal to the safety speed and the timing time length reaches the safety deceleration time length.

[0064] The embodiment realizes the comparison circuit through the comparator, the circuit structure is simple, and the deceleration monitoring module 10 can be realized through the design mode of pure hardware and simple logic circuit, and does not depend on the participation of software; further, the off signal and the deceleration signal are set as low levels, so that the deceleration signal and the off signal are logically the same, the convenience of safety control can be improved, the recognizability is high, and the operator can easily identify.

[0065] Of course, in other embodiments, the deceleration signal and the off signal can also adopt high-level signals, and the related driving circuit of the motor can be adaptively adjusted.

[0066] Of course, the comparison module 12 also includes the peripheral circuit of the comparator, for example, a reference voltage providing circuit and / or a voltage dividing circuit and the like.

[0067] Optionally, the safety speed generation module 11 of the embodiment can include a timing and slope signal generation circuit, and the specific circuit structure of the circuit can be referred to FIG. 8. The safety speed generation module 11 includes an amplification circuit, a first resistor R1, a capacitor C1 and a switch S1. The first input end of the amplification circuit is used to access a first power supply signal. One end of the first resistor R1 accesses a second power supply signal, and the other end of the first resistor R1 is connected with the second input end of the amplification circuit. One end of the capacitor C1 is connected with the other end of the first resistor R1 and the second input end of the amplification circuit, and the other end of the capacitor C1 is connected with the output end of the amplification circuit. The switch S1 is connected with the second input end of the amplification circuit and the output end of the amplification circuit respectively.

[0068] When the switch S1 is closed, the capacitor C1 is in a non-charging state, so that the voltage of the input end of the comparison module 12 and the slope output voltage are constant, so that the comparison module 12 has no off signal output. When the switch S1 is opened, that is, the timing starts, the capacitor C1 is in a constant current charging state, so as to linearly adjust the voltage of the input end of the comparison module 12 to a preset voltage, that is, a voltage corresponding to an actual speed (the voltage can be obtained by an encoder or the like speed detection piece). At this time, the comparison module 12 outputs the off signal.

[0069] Optionally, the safety speed generation module 11 further includes a second resistor R2 and a third resistor R3. The second power supply signal is divided by the second resistor R2 to be the first power supply signal, so as to be provided to the amplification circuit.

[0070] Optionally, the amplification circuit includes a comparator U1, and the comparison module 12 includes a comparator W1.

[0071] When the switch S1 is opened, the robot enters the deceleration stage, and the first starting speed of the robot in the deceleration stage is processed and converted into a second power supply signal V. The safety speed generation module 11 generates a slope signal based on the second power supply signal V and a safety deceleration time length, that is, a safety speed signal.

[0072] In this embodiment, the charging time of the capacitor C1 is linearly related to the charging voltage; and R3 and R2 can be selected so that R2 << R3, so that the charging current of the capacitor C1 is very small, thereby making the charging time of the capacitor C1, i.e., the timing duration, very long; compared with the prior art RC circuit which prolongs the timing by taking a larger resistance and capacitor, the RC element of this embodiment is small in size, low in cost and small in error.

[0073] Of course, in other embodiments, other conventional circuits capable of realizing timing and slope signals can be used instead of the embodiment of FIG. 8.

[0074] Optionally, the embodiment can also acquire the speeds of multiple motors through multiple comparators W1 to realize the monitoring of the same safety speed on multiple speeds.

[0075] Optionally, the output module 20 in the embodiment includes a buffer, and an enable pin of the buffer is connected with an output end of the deceleration monitoring module 10.

[0076] The enable pin of the buffer can be connected with an output end of the comparator in the deceleration monitoring module 10.

[0077] The shutdown signal can include a low-level signal, and the enable pin of the buffer is high-level effective, so when the comparator outputs a low-level signal to the buffer, the buffer is disabled, and then the buffer cannot work, at this time, the drive control instruction transmitted by the controller to the buffer cannot be further transmitted to the motor (or the drive circuit of the motor), and the motor stops working, thereby realizing torque shutdown.

[0078] In other embodiments, the shutdown signal can include a high-level signal, and the embodiment needs to select a buffer with a low-level effective enable pin, so when the comparator outputs a high-level signal to the buffer, the buffer is disabled, and then the buffer cannot work, at this time, the drive control instruction transmitted by the controller to the buffer cannot be further transmitted to the motor (or the drive circuit of the motor), and the motor stops working, thereby realizing torque shutdown.

[0079] Optionally, in other embodiments, the output module can also include a logic device, or be formed by the combination of a buffer and a logic device.

[0080] It should be noted that the above speed and the like exist in the form of voltage, which is convenient for the above circuit to process.

[0081] The application further provides another embodiment of the torque-off module, as shown in Figure 9, which is a structural schematic diagram of another embodiment of the torque-off module of the application. The torque-off module of the embodiment further comprises a latch module 30 connected with the speed reduction monitoring module 10 and the output module 20, the latch module 30 receives the off signal from the speed reduction monitoring module 10 and latches the off signal to make the output module 20 continuously output the off signal.

[0082] Specifically, the latch module 30 is connected with the comparison module 12 in the speed reduction monitoring module 10.

[0083] Optionally, the latch module 30 can comprise an RS flip-flop or the like, once the off signal output by the comparison module 12 at any time is low, the low level is latched and kept by the RS flip-flop, even if the off signal is flipped to high level afterwards, the RS flip-flop still keeps low level output, thereby ensuring continuous cut-off of the motor torque output.

[0084] The embodiment can make the output module 20 continuously output the off signal by latching the off signal output by the speed reduction monitoring module 10 through the latch module 30, thereby making the motor torque-off continuously maintain in the torque-off state, and avoiding the problem of abnormal motor speed reduction and excessive braking distance caused by the motor re-outputting torque when the actual speed of the motor is less than the safe speed after torque-off.

[0085] However, the speed reduction monitoring module 10, the output module 20 and the like of the torque-off module of the above-mentioned embodiment are single-loop architectures, when at least one of the speed reduction monitoring module 10, the output module 20 and the like is abnormal, the power supply of the motor cannot be cut off to control the robot to stop moving, and the safety reliability is low.

[0086] On the basis of the above-mentioned embodiment, the application further provides another torque-off module to improve the safety reliability of the torque-off module. As shown in Figure 10, which is a structural schematic diagram of another embodiment of the torque-off module of the application. The torque-off module of the embodiment differs from the embodiment of Figure 9 in that the torque-off module of the embodiment comprises two speed reduction monitoring modules 10 and two output modules 20, each speed reduction monitoring module 10 is connected with the two output modules 20, and each output module 20 outputs the off signals output by the two speed reduction monitoring modules 10, so that the motor of the moving part performs torque-off based on any off signal.

[0087] The embodiment adopts a double-loop architecture, which can avoid the problem of abnormal output of the off signal caused by abnormality of a certain loop, thereby further improving the safety of the speed reduction control of the robot, meeting the Cat3 architecture requirement of the international standard ISO-13849, thereby reaching the PLd, SIL2 safety level requirement, and improving the safety reliability of the torque-off module.

[0088] Optionally, the output module 20 can also include an AND gate circuit.

[0089] As shown in FIG. 6 and FIG. 7, before t0, the motor is in normal operation, the enable signals (or stop signals) SFO_A and SFO_B are both high signals, the safe speed of the deceleration monitoring module 10 always follows the change of the actual speed Speed_A and Speed_B of the motor, and is slightly greater than the actual speed signal of the motor (for example, safe speed = actual speed * 1.05, wherein the coefficient 1.05 can be determined according to actual needs), so that the safe speed > actual speed, and the output signals Comp_A and Comp_B of the comparator thereafter are high, and after passing through the AND gate circuit, the generated STO_A and STO_B are also high signals, so that the motor can continue to work normally and generate torque output.

[0090] When the motor needs to decelerate and stop (at t0), SFO_A and SFO_B change from high to low, and the motor starts to decelerate (controlled by the motor drive circuit), at which time the deceleration monitoring module 10 starts timing, and its output signal is a ramp signal that linearly decreases with time according to a preset slope until the ramp signal decreases to 0 at t1.

[0091] Optionally, the preset slope of the ramp signal is the speed change rate of the normal deceleration of the motor.

[0092] Because the actual speed at t0 is still lower than the safe speed, the output of the comparator maintains high, so the motor can still decelerate under the control of the motor drive circuit. If the motor does not have an abnormality during the deceleration phase (from t0 to t1), as shown in FIG. 7, the actual speed is always lower than the safe speed, the output of the comparator maintains high, and the STO output maintains high, that is, the deceleration monitoring module 10 does not interfere with the control of the motor. After t1, when the safe speed decreases to 0, the output of the comparator is low. After passing through the two AND gates, the generated STO is also a low signal, which is sent to the drive circuit of the motor to cut off the torque output of the motor.

[0093] If the motor has an abnormality during the deceleration phase, as shown in FIG. 6, t triggerAt the moment, the actual speed exceeds the safe speed, the comparator outputs a low-level signal. After passing through two AND logic gates, the STO generated is also a low-level signal, which is sent to the motor drive circuit to cut off the motor output torque. The latch module 30 after the comparator is used to latch the output of the comparator. That is, once the comparator outputs a low level, the latch module 30 can ensure that the STO is low level in the following time, even if the comparator output flips to high level, the output of the latch module 30 remains low level, and the motor output torque is reliably cut off. The above logic function is realized by two identical circuits, and the output of the latch module 30 of any one of the two paths is a low-level signal. The STO output by the AND logic gate of the two paths is a low-level signal. The architecture is a dual-channel redundant architecture, which meets the Cat3 architecture requirement of ISO13849.

[0094] In this application, the STO is a delayed output of the SFO. During the delay period, the speed of the motor is also monitored in a ramp manner, and the SS1-r function is realized.

[0095] The output module of the embodiment can also be realized by a buffer or the like.

[0096] Similar improvements can be made to the above other embodiments.

[0097] All circuit elements in the torque shutdown module of the embodiment are simple logic elements, and the formed circuit is a simple logic circuit of pure hardware, which has the advantages of simple circuit structure, small size, low production cost and short certification period.

[0098] In some embodiments, the torque shutdown module can further include a signal acquisition module connected to the speed monitoring module, configured to acquire the actual speed of the moving part and transmit the actual speed to the speed monitoring module.

[0099] For example, in the embodiment of FIG. 10, two speeds Speed_A and Speed_B are obtained by a double encoder. The double encoder can be replaced by a single output safety encoder, and Speed_A and Speed_B can share the same speed signal.

[0100] The application also provides a motor torque shutdown method. The execution subject of the motor torque shutdown method can be the torque shutdown module described in any of the above embodiments. Please refer to FIG. 11, which is a flowchart of an embodiment of the motor torque shutdown method of the application. Specifically, as shown in FIG. 11, the specific steps of the motor torque shutdown method of the embodiment include:

[0101] Step S31: receiving the actual speed of the moving part in the deceleration stage.

[0102] The embodiment receives the shutdown signal through the deceleration monitoring module shown in the above embodiment, starts timing at the moment of receiving the shutdown signal, obtains the deceleration duration, and obtains the actual speed of the moving part in the deceleration stage.

[0103] Optionally, the shutdown signal can be received through the safe speed generation module, timing is started at the moment of receiving the shutdown signal, and the actual speed of the moving part in the deceleration stage is obtained.

[0104] Step S32: In response to the actual speed being greater than the safe speed, outputting the shutdown signal.

[0105] The embodiment compares the actual speed with the safe speed through the comparison module shown in the above embodiment, outputs the shutdown signal when the actual speed is greater than the safe speed, and the output module receives the shutdown signal and further outputs the motor connected thereto, so as to control the motor of the mobile robot to perform torque shutdown based on the shutdown signal.

[0106] Step S33: In response to the actual speed being less than or equal to the safe speed, obtaining the deceleration duration of the moving part, and outputting the shutdown signal through the output module when the deceleration duration reaches the safe deceleration duration.

[0107] The embodiment compares the actual speed with the safe speed through the comparison module shown in the above embodiment, continues timing when the actual speed is less than or equal to the safe speed, outputs the shutdown signal when the timing duration, i.e., the deceleration duration, reaches the safe deceleration duration, and the output module receives the shutdown signal and further outputs the motor connected thereto, so as to control the motor of the mobile robot to perform torque shutdown based on the shutdown signal.

[0108] The embodiment can monitor the actual speed of the moving part in the deceleration stage, and output the shutdown signal when the actual speed is greater than the safe speed, so as to control the motor of the moving part to perform torque shutdown when the actual speed of the moving part in the deceleration stage exceeds the safe speed, so that the actual speed of the moving part will not exceed the safe speed, and the problem of brake not timely or brake distance being too long caused by abnormal deceleration in the deceleration process can be improved, thereby improving the reliability of torque shutdown control. Further, the torque shutdown signal is outputted when the actual speed is less than or equal to the safe speed, and the deceleration duration in the deceleration stage reaches the safe deceleration duration, so as to not only make the moving part decelerate in the safe speed range and make the deceleration duration in the safe deceleration duration, but also reduce the damage to the motor caused by the control motor emergency stop.

[0109] Some other expansion schemes of the motor torque shutdown can refer to the above embodiments, which will not be described here.

[0110] The application further provides a safety control module. Please refer to FIG. 12, which is a structural schematic diagram of an embodiment of the safety control module of the application. As shown in FIG. 12, the safety control module 40 of the embodiment comprises an instruction generation module 41 and a torque shutdown module 42. The torque shutdown module 42 is the torque shutdown module described in any of the above embodiments, and will not be described herein.

[0111] Specifically, the instruction generation module 41 is connected to the torque shutdown module 42, for outputting a deceleration signal to the torque shutdown module 42. The output end of the torque shutdown module 42 is connected to the motor of the robot, for outputting a shutdown signal to the motor. The instruction generation module can be an external safety input device, such as an emergency stop button, a safety door lock, a safety optical grating, a laser radar, a hand pressure switch, a latch switch, a safety tension switch, a cable interlock switch, a safety enable switch, a safety limit switch, a safety carpet switch, etc.

[0112] The application further provides a robot. Please refer to FIG. 13, which is a structural schematic diagram of an embodiment of the robot of the application. As shown in FIG. 13, the robot 50 of the embodiment comprises a main body 51, a motor 52 and a safety control module 40.

[0113] Specifically, the motor 52 and the safety control module 40 are both arranged on the main body 51, and the safety control module 40 is connected to the motor 52, for controlling the torque shutdown of the motor 52 by outputting a shutdown signal.

[0114] The torque shutdown module provided by the application is provided with a deceleration monitoring module, which can monitor the actual speed of the moving member in the deceleration stage, and output a shutdown signal when the actual speed is greater than the safety speed. Thus, the moving member can output a shutdown signal when the actual speed in the deceleration stage exceeds the safety speed, so as to control the motor of the moving member to perform torque shutdown, so that the actual speed of the moving member will not exceed the safety speed, and the problem of untimely braking or excessively long braking distance caused by abnormal deceleration in the deceleration process can be improved, thus the reliability of torque shutdown control can be improved. Further, the torque shutdown signal is outputted when the actual speed is less than or equal to the safety speed, and the deceleration time length in the deceleration stage reaches the safety deceleration time length. Thus, the moving member can be decelerated within the safety speed range and the deceleration time length can be within the safety deceleration time length, and the damage caused by the control of the motor emergency stop to the motor can be reduced.

[0115] The above is only an embodiment of the application, and does not limit the patent scope of the application. Any equivalent structure or equivalent process transformation based on the content of the specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the application.

Claims

1. A torque shutdown module, wherein, The torque shutdown module includes: The deceleration monitoring module receives the actual speed of the moving part during the deceleration phase; the deceleration monitoring module outputs a shutdown signal when the actual speed is greater than the safe speed; the deceleration monitoring module outputs a shutdown signal when the actual speed is less than or equal to the safe speed and the deceleration time reaches the safe deceleration time. The output module is connected to the deceleration monitoring module and outputs the shutdown signal output by the deceleration monitoring module.

2. The torque shut-off module according to claim 1, wherein, The deceleration monitoring module generates a safe deceleration curve based on the first starting speed of the deceleration phase and the safe deceleration duration, and obtains the safe speed based on the safe deceleration curve. The safe speed of the safe deceleration curve decreases linearly with a preset slope, and the second starting speed of the safe deceleration curve is greater than the first starting speed.

3. The torque shut-off module according to claim 1 or 2, wherein, The deceleration monitoring module includes: The safe speed generation module receives the deceleration signal and starts timing, and acquires and outputs the safe speed; The comparison module is connected to the safe speed generation module and the output module respectively. The comparison module outputs the shutdown signal when the actual speed is greater than the safe speed; the comparison module outputs the shutdown signal when the actual speed is less than or equal to the safe speed and the deceleration time reaches the safe deceleration time.

4. The torque shut-off module according to claim 1, wherein, The torque shutdown module also includes: A latching module is connected to both the deceleration monitoring module and the output module. The latching module receives the shutdown signal from the deceleration monitoring module and latches the shutdown signal so that the output module continuously outputs the shutdown signal.

5. The torque shutdown module according to claim 1, wherein, The torque shutdown module includes: two deceleration monitoring modules and two output modules, with each deceleration monitoring module connected to the two output modules; Each of the output modules outputs the shutdown signal from the two deceleration monitoring modules, so that the motor of the moving part performs torque shutdown based on any of the shutdown signals.

6. The torque shutdown module according to claim 5, wherein, The output module includes: logic gates or buffers.

7. The torque shutdown module according to claim 1, wherein, The torque shutdown module also includes: The signal acquisition module is connected to the deceleration monitoring module and is used to acquire the actual speed of the moving part.

8. A method for cutting off motor torque, wherein, include: Receive the actual speed of the moving part during the deceleration phase; In response to the actual speed being greater than the safe speed, a shutdown signal is output; In response to the actual speed being less than or equal to the safe speed, the deceleration duration of the moving part is obtained, and a shutdown signal is output when the deceleration duration reaches the safe deceleration duration.

9. A safety control module, wherein, The safety control module includes an instruction generation module and a torque shutdown module as described in any one of claims 1-7. The instruction generation module is connected to the torque shutdown module and is used to output the deceleration signal to the torque shutdown module. The output terminal of the torque shutdown module is connected to a motor and is used to output the shutdown signal to the motor.

10. A robot, wherein, include: main body; The motor is mounted on the main body; A safety control module is installed in the main body and connected to the motor. The safety control module controls the motor torque to shut off by outputting a shutdown signal. The security control module is the security control module described in claim 9.

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