Industrial robot and brake state monitoring method thereof

Abstract

The present invention relates to an industrial robot and a brake state monitoring method thereof, wherein the industrial robot comprises a connecting rod and a joint, wherein the joint comprises a driving motor and a brake, wherein the brake comprises: an annular brake element, a stop pin, and an electromagnet, wherein the annular brake element is sleeved on the motor shaft of the driving motor and rotates with it, wherein the electromagnet comprises an iron core and a coil, wherein the iron core is in different positions when the coil is energized and de-energized, and wherein the stop pin limits the rotation of the annular brake element to brake the joint when the coil is in an extended state; wherein the joint comprises: an information acquisition module for applying pulse excitation to the electromagnet, detecting the voltage and / or current of the electromagnet, and obtaining the inductance of the electromagnet; and a signal processing module for judging the position of the iron core according to the inductance of the electromagnet, and determining whether the electromagnet is working normally. The beneficial effects of the present invention are: the industrial robot has good safety and accurate fault judgment.

Description

Technical Field

[0001] The present invention relates to the field of industrial robots, and in particular to an industrial robot and a brake state monitoring method thereof. Background Art

[0002] Industrial robots are a type of robot widely used in industrial environments. The joints of the robot are one of its core components. The joints include drive motors and brakes. The drive motors are the power source of the joints, and the brakes can brake the joints to stop the movement of the robot.

[0003] The joints of industrial robots need to be in a braking state or a released braking state according to work requirements. That is, when the robot needs to perform work, the joints are in a released braking state, and when the robot does not perform work and needs to shut down, the joints are in a braking state. If the brake fails to work properly due to an abnormality, and the industrial robot fails to handle the abnormality, the industrial robot may have safety risks. For example, when the brake fails to brake successfully and the robot shuts down and powers off directly, the robot may fall on its arm, which will directly damage the robot.

[0004] Therefore, it is necessary to design a method for monitoring the status of industrial robots and their brakes that is simple to implement and safe. Summary of the invention

[0005] In view of this, an object of the present invention is to provide an industrial robot and a brake monitoring method thereof which is simple to implement and has good safety.

[0006] The present invention can adopt the following technical scheme: an industrial robot includes a connecting rod and a joint, the joint includes a driving motor and a brake, the brake includes: an annular brake element, a stop pin, and an electromagnet, the annular brake element is sleeved on the motor shaft of the driving motor and rotates with it, the electromagnet includes an iron core and a coil, the iron core is in different positions when the coil is energized and de-energized, the stop pin is in an extended state or a retracted state according to different positions of the iron core, and when the stop pin is in an extended state, it limits the rotation of the annular brake element to brake the joint, and the joint includes: a signal acquisition module, which is used to apply pulse excitation to the electromagnet, detect the voltage and / or current of the electromagnet, and obtain the inductance of the electromagnet; a signal processing module, which is used to judge the position of the iron core according to the inductance of the electromagnet and determine whether the electromagnet is working normally.

[0007] Furthermore, the joint has a braking state and a releasing state. When the joint should be in the braking state, the signal acquisition module applies a positive excitation pulse to the electromagnet to obtain the inductance of the electromagnet; when the joint should be in the releasing state, the signal acquisition module applies a negative excitation pulse to the electromagnet to obtain the inductance of the electromagnet.

[0008] Furthermore, the signal acquisition module is used to apply pulse excitation to the electromagnet before the robot is powered on to perform work and before the robot finishes performing work and powers off to obtain the inductance of the electromagnet.

[0009] Furthermore, the signal processing module is used to set a preset inductance, compare the inductance of the electromagnet with the preset inductance, and determine that the electromagnet is working normally when a condition is met.

[0010] Furthermore, the signal processing module is used to confirm that the electromagnet is not working properly when the inductance of the electromagnet does not meet the condition at least three times in a row.

[0011] Furthermore, the signal processing module is used to control the robot to maintain motor excitation and / or control the robot to send out an alarm signal when it is determined that the electromagnet is not working properly.

[0012] The present invention can also adopt the following technical scheme: a method for monitoring the brake status of an industrial robot, the industrial robot includes a connecting rod and a joint, the joint includes a driving motor and a brake, the brake includes: an annular brake element, a stop pin, and an electromagnet, the annular brake element is sleeved on the motor shaft of the driving motor and rotates with it, the electromagnet includes an iron core and a coil, the iron core is in different positions when the coil is energized and de-energized, and the stop pin limits the rotation of the annular brake element to brake the joint when it is in an extended state, and the monitoring method includes: an acquisition step: applying a pulse excitation to the electromagnet, monitoring the voltage and / or current of the electromagnet, and obtaining the inductance of the electromagnet; a processing step: further, the joint has a braking state and a brake release state, and the acquisition step includes: when the joint should be in a braking state, applying a positive pulse excitation to the electromagnet; when the joint should be in a brake release state, applying a negative pulse excitation to the electromagnet.

[0013] Furthermore, the acquisition step includes: applying pulse excitation to the electromagnet before the robot is powered on to perform work and before the robot is powered off after completing the work, so as to obtain the inductance of the electromagnet.

[0014] Furthermore, the processing step includes: when it is determined that the electromagnet is not working properly, controlling the robot to maintain motor excitation, and / or controlling the robot to send out an alarm signal.

[0015] Compared with the prior art, the beneficial effects of the specific implementation methods of the present invention are as follows: the industrial robot obtains inductance by applying pulse excitation to the electromagnet, confirms the core position to determine whether the electromagnet is working normally, thereby avoiding unsafe factors in the robot caused by electromagnet failure, and can accurately lock the cause of the robot's braking failure, which is conducive to troubleshooting and safe operation of the robot. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The above-mentioned objectives, technical solutions and beneficial effects of the present invention can be achieved through the following drawings:

[0017] Figure 1 Schematic diagram of an industrial robot according to an embodiment of the present invention

[0018] Figure 2 Schematic diagram of the joint decomposition of an industrial robot according to an embodiment of the present invention

[0019] Figure 3 Schematic diagram of an iron core in a release position and an adsorption position according to an embodiment of the present invention

[0020] Figure 4 Schematic diagram of an industrial robot joint in a braking state according to an embodiment of the present invention

[0021] Figure 5 Schematic diagram of an industrial robot joint in a brake-released state according to an embodiment of the present invention

[0022] Figure 6 Schematic diagram of the change of the voltage of the electromagnet according to an embodiment of the present invention

[0023] Figure 7 This is a time domain current waveform diagram of an electromagnet according to an embodiment of the present invention.

[0024] Figure 8 Schematic diagram of a brake state monitoring method according to an embodiment of the present invention DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the present invention clearer, the scheme in the embodiment of the present invention will be described clearly and completely in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention but not all of the embodiments. Based on the embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] The present invention protects an industrial robot, Figure 1-Figure 2 , Figure 1 is a schematic diagram of an industrial robot 10 according to an embodiment of the present invention, Figure 21 is a schematic diagram of the joint decomposition of an industrial robot 10 according to an embodiment of the present invention. The industrial robot 10 includes a connecting rod 1 and a joint 2, wherein the joint 2 includes a driving motor 21 and a brake, wherein the brake includes: an annular brake element 24, a stop pin 22, and an electromagnet 23. The driving motor 21 provides a power source for the joint 2, wherein the annular brake element 24 is sleeved on the motor shaft 25 of the driving motor 21 and rotates with the motor, wherein the electromagnet 23 includes an iron core 231 and a coil, wherein the iron core 231 is in different positions when the coil is energized or de-energized, wherein the stop pin 22 is in an extended state or a retracted state according to different positions of the iron core 231, and wherein the stop pin 22 is in an extended state and in contact with the annular brake element 24 to brake the joint 2 when in an extended state. The joint 2 includes: an information acquisition module for applying pulse excitation to the electromagnet 23, detecting the voltage and / or current of the electromagnet 23, and obtaining the inductance of the electromagnet 23; a signal processing module for judging the position of the iron core 231 according to the inductance of the electromagnet 23, and determining whether the electromagnet 23 is working properly. Figure 3 , Figure 3 a and Figure 3 b shows schematic diagrams of the iron core 231 in the release position and the adsorption position, respectively. The iron core 231 has a release position and an adsorption position. When the coil is energized, the iron core 231 is adsorbed and is in the adsorption position, and the stop pin 22 contacts the iron core 231. The stop pin 22 is in a retracted state according to the iron core 231 being in the adsorption position; when the coil is de-energized, the iron core 231 is released and is in the release position, and the stop pin 22 contacts the iron core 231. The stop pin 22 is in an extended state according to the iron core 231 being in the release position, thereby limiting the rotation of the annular brake element 24 to brake the joint. When the coil is energized, the iron core 231 is adsorbed, the stop pin 22 is in a retracted state, the annular brake element 24 can rotate freely, and the joint is in a released braking state; when the coil is de-energized, the iron core 231 is released, the stop pin 22 is in an extended state, which can limit the rotation of the annular brake element 24, and the joint is in a braking state. When the iron core 231 is in different positions, the inductance obtained by the signal acquisition module is different. Specifically, when the iron core is in the adsorption position, the inductance is relatively small, and when the iron core is in the release position, the inductance is relatively large, so that the position of the iron core 231 can be judged according to the different inductances, and whether the electromagnet 23 is working normally can be determined, thereby determining whether the brake is braking normally. Specifically, the industrial robot 10 provided by the present invention detects whether the brake is working normally, avoids safety risks such as arm smashing caused by robot abnormalities, and has good robot safety. At the same time, the hardware design is simple and easy to implement.

[0027] Ginseng Figure 4-Figure 5, the joint 2 of the industrial robot 10 has a braking state and a releasing braking state, Figure 4 and Figure 5 Schematic diagrams showing the joint 2 in a braking state and a released braking state respectively. When the joint 2 is in a braking state, the stop pin 22 is in an extended state and the iron core is in a released position; when the joint 2 is in a released braking state, the stop pin 22 is in a retracted state and the iron core is in an adsorbed position.

[0028] When the joint 2 should be in a braking state, the signal acquisition module applies a positive pulse excitation to the electromagnet 23 to obtain the inductance; when the joint 2 should be in a brake release state, the signal acquisition module applies a negative pulse excitation to the electromagnet 23 to obtain the inductance. Specifically, when the joint 2 should be in a braking state, the stop pin 22 should be in an extended state, the iron core 231 should be in a released position, and the coil is in a de-energized state. At this time, the signal acquisition module applies a positive pulse excitation to the electromagnet 23, detects the voltage and / or current of the electromagnet 23, and obtains the inductance of the electromagnet 23 to determine whether the iron core 231 is in a released position and whether the stop pin 22 is in an extended state, so as to determine whether the electromagnet 23 is working normally, and then determine whether the brake is working normally. When the joint 2 should be in the brake release state, the stop pin 22 should be in the retracted state, the iron core 231 is in the adsorbed position, and the coil is in the energized state. At this time, the signal acquisition module applies a negative pulse excitation to the electromagnet 23, detects the voltage and / or current of the electromagnet 23, and obtains the inductance of the electromagnet 23 to determine whether the iron core 231 is in the adsorbed position and whether the stop pin 22 is in the retracted state. Further, the positive pulse represents a high voltage pulse in a low level state, and the negative pulse represents a low voltage pulse in a high level state. For example, when the joint should be in the brake state, the coil of the electromagnet is in the de-energized state, the electromagnet is in the low level state, and a positive pulse excitation is applied to it, that is, a high voltage pulse is applied to it; and when the joint should be in the brake release state, the coil of the electromagnet is in the energized state, the electromagnet is in the high level state, and a negative pulse excitation is applied to the electromagnet, that is, a low voltage pulse is applied to it. Furthermore, the pulse excitation is a short-time pulse excitation, which only changes the voltage and current of the electromagnet 23 to obtain the inductance change, and does not substantially change the state of the electromagnet 23 due to the pulse excitation. Further, when the joint 2 should be in a brake release state, the signal acquisition module applies a negative pulse excitation to the electromagnet 23, while maintaining the energized state of the electromagnet 23 to avoid the state of the iron core 231 switching to the release position. By applying pulse excitations of different directions to the electromagnet 23 in different states, the changes in the voltage and current of the electromagnet 23 are more obvious, and the inductance change can be obtained based on this to know the position of the iron core 231 and then determine whether the electromagnet 23 is working normally.

[0029] The joint 2 of the robot has a braking state and a brake release state. Before the robot 10 is powered on to perform work, the brake needs to be released before the work can be performed; when the robot 10 finishes the work and powers off, it must brake before it can power off to ensure the safety of the robot. The signal acquisition module is used to apply pulse excitation to the electromagnet 23 before the robot is powered on to perform work and before the robot finishes the work and powers off to obtain the inductance. Before the robot 10 is powered on to perform work, a pulse excitation is applied to detect whether the brake is working properly, and the work is started only when the brake is working properly, so as to avoid the uncontrollable results that may be caused by the robot 10 starting to work under a braking failure; before the robot 10 finishes the work and powers off, a pulse excitation is applied to detect whether the brake is working properly, and the power is turned off only when the brake is working properly, so as to avoid the danger of the robot 10 breaking the arm when the brake fails to work properly. Further, the signal acquisition module is used to apply positive pulse excitation to the robot before it is powered on to perform work, obtain the inductance, and the signal processing module determines whether the iron core 231 is in the release position, and then determines whether the brake is braking normally; and when it is determined that the brake is braking normally, the brake is controlled to release the brake, and the signal acquisition module applies negative pulse excitation to the robot to determine whether the electromagnet 23 is working normally, that is, to determine whether the brake is released. Further, when the signal processing module determines that the electromagnet 23 is not working normally, an alarm signal is issued.

[0030] Figure 6It is a schematic diagram of the voltage change of the electromagnet of an embodiment of the present invention. In the figure, the T1 stage is before the industrial robot releases the brake, that is, the stage before the robot is powered on to perform work. At this time, the robot joint is in a braking state. The T2 stage in the figure is the state after the industrial robot releases the brake, that is, the robot is in the working state. In the figure, T3 is the braking state of the robot joint. The information acquisition module applies pulse excitation to the electromagnet at different stages. Specifically, in the T1 stage, the robot should be in a braking state before releasing the brake, that is, the joint state output by the control circuit of the joint is a braking state. At this time, a positive pulse excitation with a duration of T11 is applied to the electromagnet, and the voltage and / or current changes are detected to obtain the inductance to confirm the core position to determine whether the electromagnet is abnormal, thereby further confirming whether the brake is abnormal. In the T2 stage, the robot releases the brake and starts working. At this time, the robot joint should be in a brake-released state. A negative pulse excitation with a duration of T21 is applied to the electromagnet. Similar to the above, the inductance change is obtained to confirm the core position to determine whether the electromagnet is working normally. In the T3 stage, the robot joint should be in a braking state. At this time, a positive pulse excitation of T31 is applied to the electromagnet to obtain the inductance to determine whether the electromagnet is working normally. Specifically, the T1 stage corresponds to the stage before the robot is powered on and works, the T2 stage corresponds to the stage when the robot is working, and the T3 stage corresponds to the stage before the robot is powered off after finishing working.

[0031] The signal processing module is used to judge the position of the iron core 231 according to the inductance of the electromagnet 23, so as to determine whether the iron core 231 is working normally, and then determine whether the brake is working normally. The signal processing module is used to preset the inductance, compare the inductance of the electromagnet 23 with the preset inductance, and determine that the electromagnet 23 is working normally when the conditions are met. Specifically, the iron core 231 has an adsorption position and a release position. When the brake is in a braking state, the iron core 231 is in the release position, and when the brake is in a brake release state, the iron core 231 is in the adsorption position. The signal processing module is used to preset the inductance, and the preset inductance includes a preset first inductance and a preset second inductance. When the inductance of the electromagnet 23 meets the preset first inductance, it is judged that the iron core 231 is in the release position, and when the inductance of the electromagnet 23 meets the preset second inductance, it is judged that the iron core 231 is in the adsorption position. When the joint 2 should be in a braking state, if the inductance of the electromagnet 23 satisfies the preset first inductance, that is, the iron core 231 is in the release position, it is determined that the electromagnet 23 is working normally; when the joint 2 should be in a brake release state, if the inductance of the electromagnet 23 satisfies the preset second inductance, that is, the iron core 231 is in the adsorption position, it is determined that the electromagnet 23 is working normally, otherwise, it is determined that the electromagnet 23 is not working normally. Specifically, the preset first inductance and the preset second inductance are interval thresholds. When the inductance of the electromagnet 23 is in the interval, it can be determined that the iron core 231 is in the adsorption position or the release position. When the inductance of the electromagnet 23 is not in the interval, or the inductance of the electromagnet 23 is in the interval but the joint 2 is still not working normally, it can be determined that other faults have occurred in the joint 2. Accurately determining the state of the iron core 231 is conducive to the cause of the fault of the locking brake.

[0032] In some embodiments of the present invention, the position of the core of the electromagnet is determined by acquiring the inductance of the electromagnet. When the core position of the electromagnet is not consistent with the expectation, it is determined that the electromagnet is not working properly, and then it is determined that the brake is abnormal. The brake has a braking state and a brake release state. When the brake is in the braking state, the stop pin should be in an extended state, that is, the core should be in a released state. When the brake is in the brake release state, the stop pin should be in a retracted state, that is, the core should be in an adsorption state. When the core is in the adsorption state, the inductance of the electromagnet is relatively large, and when the core is in the release state, the inductance of the electromagnet is relatively small. Further, the signal acquisition module detects the voltage and / or current of the electromagnet to acquire the inductance of the electromagnet. In one embodiment of the present invention, the inductance of the electromagnet is acquired by acquiring the current of the electromagnet. Figure 7 1 is a time domain current waveform diagram of an electromagnet according to an embodiment of the present invention. Figure 7 a shows the time domain current waveform when the joint should be in the braking state and the electromagnet detection is working normally. At this time, the joint should be in the braking state, and the actual detection iron core is in the release position, and the inductance of the electromagnet is small; Figure 7 b shows the time domain current waveform when the joint should be in the braking state and the electromagnet is detected as not working properly. At this time, the joint should be in the braking state, but the actual detection iron core is in the adsorption position, and the inductance of the electromagnet is large. At this time, the electromagnet is not working properly to meet the requirement that the joint should be in the braking state; Figure 7 c shows the time domain current waveform of the electromagnet when the joint should be in the released braking state and the electromagnet is in normal working state. At this time, the joint should be in the released braking state, and the actual detection iron core is in the adsorption position, and the inductance of the electromagnet is relatively large; Figure 7 d shows the time domain current waveform when the joint should be in the released braking state, but the electromagnet is not working properly. At this time, the joint should be in the released braking state. The actual detection shows that the electromagnet is in the adsorption position and the inductance of the electromagnet is small, that is, the electromagnet is not working properly to meet the requirement that the joint should be in the released braking state.

[0033] The signal processing module is used to determine whether the electromagnet 23 is working normally. When it is determined that the electromagnet 23 is in a normal working state, that is, when the joint 2 should be in a braking state, the iron core 231 is in a released position, and when the joint 2 should be in a brake release state, the iron core 231 is in an adsorption position, and the robot is controlled to work normally. When it is determined that the electromagnet 23 is not working properly, the robot 10 is controlled to maintain motor excitation to prevent the robot joint 2 from suddenly losing power and causing the connecting rod 1 to suddenly fall, and the robot 10 is controlled to send an alarm signal to remind the user to handle it. Further, the signal processing module is used to determine that the electromagnet 23 is not working properly when the inductance of the electromagnet 23 does not meet the conditions for at least three consecutive times. Further, the industrial robot 10 includes a collaborative robot that can perform work in collaboration with humans.

[0034] The beneficial effects of the above preferred embodiments are: the industrial robot determines whether the electromagnet is working properly by obtaining the inductance of the electromagnet to detect the position of the iron core 231, and then determines whether the brake of the robot joint is working properly, and makes corresponding instructions based on the working state of the robot, thereby avoiding the risk of the robot smashing its arm and improving the safety of the robot. At the same time, determining the electromagnet failure by means of inductance is conducive to accurately locking the cause of the robot failure.

[0035] The present invention also provides a method for monitoring the brake state of an industrial robot. Figure 8The industrial robot includes a connecting rod 1 and a joint, and the joint includes a driving motor 21 and a brake. The brake includes: an annular brake element 24, a stop pin 22, and an electromagnet. The annular brake element 24 is sleeved on the motor shaft 25 of the driving motor 21 and rotates with it. The electromagnet includes an iron core 231 and a coil. The iron core 231 is in different positions when the coil is energized and de-energized. The stop pin 22 is in an extended state or a retracted state according to the position of the iron core 231. When the stop pin 22 is in an extended state, it contacts the annular brake element 24 to limit its rotation. The monitoring method includes: an acquisition step S1: applying a pulse excitation to the electromagnet, detecting the voltage and / or current of the electromagnet, and obtaining the inductance of the electromagnet; a processing step S2: judging the position of the iron core 231 according to the inductance of the electromagnet, and determining whether the electromagnet 23 is working normally.

[0036] In one embodiment of the present invention, the processing step includes: setting a preset inductance, comparing the inductance of the electromagnet 23 with the preset inductance, judging the position of the iron core 231, and determining whether the electromagnet 23 is working normally. The brake has a braking state and a brake release state. When the brake is in the braking state, the stop pin 22 is in an extended state and contacts the annular brake element 24 to limit the rotation of the annular brake element 24. Further, the setting of the preset inductance includes: setting a preset first inductance and a preset second inductance. The first inductance is used to represent the inductance of the iron core 231 in the release position, and the second inductance is used to represent the inductance of the iron core 231 in the adsorption position. When the brake is in the braking state, the iron core 231 is in the release position, and when the brake is in the brake release state, the iron core 231 is in the adsorption position. When the brake should be in a braking state, if the inductance of the electromagnet 23 satisfies the preset first inductance, it is determined that the electromagnet 23 is in a normal working state; when the brake should be in a braking release state, if the inductance of the electromagnet 23 satisfies the preset second inductance, it is determined that the electromagnet 23 is in a normal working state.

[0037] In one embodiment of the present invention, the acquisition step includes: applying pulse excitation to the electromagnet before the robot is powered on to perform work and before the robot is powered off after completing the work to obtain the inductance. The specific implementation content is consistent with the above and will not be repeated here.

[0038] In one embodiment of the present invention, the acquisition step includes: when the joint should be in a braking state, applying a positive pulse excitation to the electromagnet 23; when the joint 2 should be in a brake-released state, applying a negative pulse excitation to the electromagnet 23. When the joint should be in a braking state, the coil loses power, the iron core 231 is in a released position, a positive pulse excitation is applied to the electromagnet 23, and its voltage and / or current changes are detected, and the inductance of the electromagnet 23 is obtained accordingly, so as to determine whether the electromagnet 23 is working normally. Conversely, when the joint should be in a brake-released state, the coil is energized, and the iron core 231 is in an adsorption position. At this time, a negative pulse excitation is applied to the electromagnet 23, and its voltage and / or current changes are detected, and the inductance of the electromagnet 23 is obtained accordingly, so as to determine whether the electromagnet 23 is working normally. The specific implementation content in this embodiment is generally consistent with the above text, and will not be repeated here.

[0039] Further, when it is determined that the electromagnet is not working properly, the drive motor is kept excited and an alarm signal is issued. The drive motor 21 is kept excited to prevent the robot from suddenly losing power and causing the connecting rod 1 to fall, and an alarm signal is issued to remind the user to handle it in time.

[0040] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An industrial robot, characterized in that: The invention comprises a connecting rod and a joint, wherein the joint comprises a driving motor and a brake, wherein the brake comprises: an annular brake element, a stop pin, and an electromagnet, wherein the annular brake element is sleeved on the motor shaft of the driving motor and rotates with the motor, wherein the electromagnet comprises an iron core and a coil, wherein the iron core is in different positions when the coil is energized and de-energized, wherein the stop pin is in an extended state or a retracted state according to different positions of the iron core, wherein when the stop pin is in an extended state, the rotation of the annular brake element is limited to brake the joint, wherein the joint comprises: A signal acquisition module, used for applying pulse excitation to the electromagnet, detecting the voltage and / or current of the electromagnet, and obtaining the inductance of the electromagnet; A signal processing module, used to judge the position of the iron core according to the inductance of the electromagnet, and determine whether the electromagnet is working normally; The joint has a braking state and a release state. When the joint should be in the braking state, the signal acquisition module applies a positive excitation pulse to the electromagnet to obtain the inductance of the electromagnet; when the joint should be in the release state, the signal acquisition module applies a negative excitation pulse to the electromagnet to obtain the inductance of the electromagnet; The signal acquisition module is used to apply pulse excitation to the electromagnet before the robot is powered on to perform work and before the robot is powered off after completing the work, so as to obtain the inductance of the electromagnet; The signal processing module is used to set a preset inductance, compare the inductance of the electromagnet with the preset inductance, and determine that the electromagnet is working normally when a condition is met; The signal processing module is used to confirm that the electromagnet is not working properly when the inductance of the electromagnet fails to meet a condition at least three times in a row.

2. The industrial robot according to claim 1, characterized in that: The signal processing module is used to control the robot to maintain motor excitation and / or control the robot to send out an alarm signal when it is determined that the electromagnet is not working properly.

3. A method for monitoring the brake status of an industrial robot, characterized in that: The industrial robot comprises a connecting rod and a joint, the joint comprises a driving motor and a brake, the brake comprises: an annular brake element, a stop pin, and an electromagnet, the annular brake element is sleeved on the motor shaft of the driving motor and rotates with it, the electromagnet comprises an iron core and a coil, the iron core is in different positions when the coil is energized and de-energized, the stop pin limits the rotation of the annular brake element to brake the joint when it is in an extended state, and the monitoring method comprises: Acquisition step: applying pulse excitation to the electromagnet, monitoring the voltage and / or current of the electromagnet, and acquiring the inductance of the electromagnet; Processing steps: judging the core position according to the inductance of the electromagnet and determining whether the electromagnet works normally; The joint has a braking state and a release state, and the acquisition step includes: applying a positive pulse excitation to the electromagnet when the joint should be in the braking state; applying a negative pulse excitation to the electromagnet when the joint should be in the release state; The acquisition step includes: applying pulse excitation to the electromagnet before the robot is powered on to perform work and before the robot is powered off after completing the work to obtain the inductance of the electromagnet; When the inductance of the electromagnet fails to meet the condition at least three times in a row, it is confirmed that the electromagnet is not working normally.

4. The monitoring method according to claim 3, characterized in that: The processing step includes: when it is determined that the electromagnet is not working properly, controlling the robot to maintain motor excitation, and / or controlling the robot to send out an alarm signal.

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