Robot safety emergency stop circuit and system

Abstract

The application relates to a robot safety emergency stop circuit and system, which comprises an emergency stop switch, at least two relays and at least two emergency stop branches, the first end of each emergency stop branch is connected with the emergency stop switch, the second end of each emergency stop branch is connected with different relays respectively, the relays are connected in series, one end after the series connection is used for connecting a power supply, and the other end after the series connection is used for connecting a robot body. The emergency stop branch is used for obtaining the on-off state of the emergency stop switch, and the on-off state is used for controlling the on-off of the relay. The on-off state of the emergency stop switch is analyzed through the multiple emergency stop branches, the relays connected respectively are used for controlling the emergency stop of the robot body, the safety emergency stop of the robot body can be realized when any relay is disconnected, the safety performance of the robot safety emergency stop circuit is improved, and the robot safety emergency stop circuit can be applied to a wider use scene.

Description

Technical Field

[0001] This application relates to the field of robotics, and in particular to a robot safety emergency stop circuit and system. Background Technology

[0002] As production levels rise, the complexity of the machinery and equipment used in the production process also increases, with robots being one example. In fact, innovation in robotics technology has also boosted productivity. When human capabilities are combined with those of robots, manufacturing solutions that offer higher quality, lower costs, better ergonomics, and shorter work cycles can be achieved, thus contributing to the development of Industry 4.0 manufacturing.

[0003] However, the more complex the mechanical equipment, the greater the safety risks in controlling it. Errors in design, implementation, or operation can lead to system failure and consequently safety accidents. According to relevant functional safety standards (such as IEC 61508, IEC 62061, and ISO 13849-1 / -2 [1,2,3,4]), the current operational requirements for collaborative robot systems when using robots in industrial production or human-robot collaboration include the use of a suitable safety-related control system that conforms to ISO 13849-1 Performance Level (PL, which is divided into five levels: ae, with PLe being the highest).

[0004] Currently, most collaborative robots are designed to meet PLD (Label Level 1) safety emergency stop circuit architectures. However, in application environments with higher safety requirements, they suffer from insufficient self-check accuracy and inadequate safety performance. Summary of the Invention

[0005] Therefore, it is necessary to provide a robot safety emergency stop circuit and system that can improve safety performance in response to the above-mentioned technical problems.

[0006] In a first aspect, this application provides a robot safety emergency stop circuit, including an emergency stop switch, at least two relays and at least two emergency stop branches. The first end of each emergency stop branch is connected to the emergency stop switch, and the second end of each emergency stop branch is connected to different relays. The relays are connected in series, with one end of the series connection used to connect to the power supply and the other end of the series connection used to connect to the robot body.

[0007] The emergency stop branch is used to obtain the on / off state of the emergency stop switch and control the on / off state of the relay accordingly.

[0008] In one embodiment, the emergency stop branch includes a signal transmission circuit and a controller, the signal transmission circuit being connected to the emergency stop switch and the controller, and the controller being connected to the relay;

[0009] The controller obtains the on / off state of the emergency stop switch through the signal transmission circuit, and controls the on / off state of the relay accordingly.

[0010] In one embodiment, the signal transmission circuit includes a signal transmitting circuit and a signal receiving circuit, both of which are connected to the emergency stop switch and the controller.

[0011] In one embodiment, the signal transmitting circuit includes a high-level transmitting unit and a low-level transmitting unit. The high-level transmitting unit is connected to the emergency stop switch, the controller, and a high-level power supply. The low-level transmitting unit is connected to the emergency stop switch and the controller, and is grounded.

[0012] In one embodiment, the signal transmission circuit further includes an output driving circuit and a fault feedback circuit. The output driving circuit is connected to the controller, the input terminal of the high-level transmission unit, and the input terminal of the low-level transmission unit. The fault feedback circuit is connected to the controller, the output terminal of the high-level transmission unit, and the output terminal of the low-level transmission unit.

[0013] In one embodiment, the high-level transmitting unit includes a current-sensing resistor, an overcurrent protection circuit, and a high-level output circuit. The current-sensing resistor is connected to the high-level power supply, the high-level output circuit, and the overcurrent protection circuit. The overcurrent protection circuit is connected to the high-level power supply and the high-level output circuit. The high-level output circuit is connected to the controller and the emergency stop switch.

[0014] In one embodiment, the signal receiving circuit includes a signal sampling circuit and a signal modulation circuit, the signal sampling circuit being connected to the controller and the signal modulation circuit, and the signal modulation circuit being connected to the emergency stop switch.

[0015] In one embodiment, the robot safety emergency stop circuit further includes a relay detection circuit, which is connected to both ends of the relays connected in series, and is used to detect whether each relay is functioning properly.

[0016] In one embodiment, the relay detection circuit includes a push-pull output circuit and a square wave receiving circuit. The push-pull output circuit is connected to one end of the relay connected in series, and the square wave receiving circuit is connected to the other end of the relay connected in series.

[0017] Secondly, this application also provides a robot safety emergency stop system, including a robot body, a power supply, and a robot safety emergency stop circuit as described above, wherein the robot safety emergency stop circuit is connected to the robot body and the power supply.

[0018] The aforementioned robot safety emergency stop circuit and system includes an emergency stop switch, at least two relays, and at least two emergency stop branches. The first end of each emergency stop branch is connected to the emergency stop switch, and the second end of each branch is connected to a different relay. These relays are connected in series, with one end connected to a power source and the other end connected to the robot body. The emergency stop branches are used to acquire the on / off state of the emergency stop switch and control the on / off state of the relays accordingly. By setting multiple emergency stop branches to analyze the on / off state of the emergency stop switch and then controlling the robot body's emergency stop through the connected relays, a safe emergency stop can be achieved when any relay is disconnected. This improves the safety performance of the robot safety emergency stop circuit and allows it to be applied to a wider range of scenarios. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of a robot safety emergency stop circuit in one embodiment;

[0021] Figure 2 This is a schematic diagram of the emergency stop branch in one embodiment;

[0022] Figure 3 This is a schematic diagram of the robot safety emergency stop circuit in another embodiment;

[0023] Figure 4 This is a schematic diagram of the emergency stop branch in another embodiment;

[0024] Figure 5 This is a schematic diagram of the signal transmission circuit in one embodiment;

[0025] Figure 6 This is a schematic diagram of the high-level transmitting unit in one embodiment;

[0026] Figure 7 This is a circuit diagram of an overcurrent protection circuit in one embodiment;

[0027] Figure 8This is a schematic diagram of the low-level transmitting unit in one embodiment;

[0028] Figure 9 This is a schematic diagram of the signal receiving circuit in one embodiment;

[0029] Figure 10 This is a schematic diagram of the relay detection circuit in one embodiment. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. The accompanying drawings illustrate embodiments of this application; however, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to make the disclosure of this application more thorough and complete. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0031] It is understood that the terms "first," "second," etc., used herein may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0032] It is understood that the term "connection" in the following embodiments should be understood as "electrical connection," "communication connection," etc., if the connected circuits, modules, units, etc., have electrical signal or data transmission with each other.

[0033] It is understandable that "at least one" refers to one or more, and "multiple" refers to two or more. "At least a part of an element" refers to part or all of an element.

[0034] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0036] In the use of robots, collaboration with human workers is inevitable to improve production efficiency. Therefore, ensuring worker safety is a key design requirement for robots. Robots need to be able to stop immediately in case of unexpected situations or when production steps need to be redefined to ensure the reliability of the production process. Typically, robots are configured with PL level d safety protection, with a hardware architecture of cat.3 (Category, describing the capability level of the user terminal), achieving a self-checking rate of 60-90%. However, with the development of industrial manufacturing, the scenarios in which robots and workers collaborate are becoming increasingly diverse, and the demand for robot safety protection is also increasing. The original PLd safety protection is no longer sufficient to meet all safety requirements. The robot safety emergency stop circuits provided in the following embodiments of this application meet the PLe safety protection level of ISO 13849-1, using a cat.4 architecture to achieve emergency stop control of the robot, ensuring safety and reliability during emergency stop control. The robot safety emergency stop circuits provided in the embodiments of this application can be applied to various robot operation scenarios to assist workers in achieving emergency stops of the robot. The types and specifications of robots are not limited, such as collaborative robots and multi-axis robotic arms.

[0037] In one embodiment, such as Figure 1 As shown, a robot safety emergency stop circuit is provided, including an emergency stop switch 102, at least two relays 104, and at least two emergency stop branches 106. The first end of each emergency stop branch 106 is connected to the emergency stop switch 102, and the second end of each emergency stop branch 106 is connected to a different relay 104. The relays 104 are connected in series, with one end connected to a power supply 120 and the other end connected to the robot body 140. The emergency stop branches 106 are used to obtain the on / off state of the emergency stop switch 102 and control the on / off state of the relays 104 accordingly.

[0038] Specifically, in the event of an unexpected emergency or when it is necessary to urgently pause the operation of the robot body 140, the operator can trigger the emergency stop switch 102 to stop the robot body 140 from working. In this embodiment, the emergency stop branch 106 is connected to the emergency stop switch 102 to obtain the on / off state of the emergency stop switch 102. When the emergency stop switch 102 is not triggered, the circuit is closed, which is equivalent to a short circuit. When the operator triggers the emergency stop switch 102, the emergency stop branch 106 detects that the emergency stop switch 102 is open, and the emergency stop branch 106 controls the connected relay 104 to disconnect, thus cutting off the power supply circuit between the power supply 120 and the robot body 140, stopping the robot body 140 from working, and realizing control of the robot body 140.

[0039] Each emergency stop branch 106 is connected to the emergency stop switch 102 through different ports, enabling separate acquisition of the on / off state of the emergency stop switch 102. Each relay 104 connected to each emergency stop branch 106 is connected in series. When any emergency stop branch 106 controls one of the relays 104 to open, emergency stop control of the robot body 140 can be achieved, ensuring reliable emergency stop control and safe operation of the robot body 140.

[0040] Furthermore, the emergency stop branches 106 are interconnected, enabling the transmission of the acquired on / off status of the emergency stop switch 102 and facilitating data cross-checking between different emergency stop branches 106. Cross-checking further verifies the on / off status of the emergency stop switch 102, reducing false triggering and making the robot's emergency stop control more accurate.

[0041] Meanwhile, multiple emergency stop branches 106 and corresponding connected relays 104 are set up to achieve redundant backup of the safety emergency stop circuit, enhancing the reliability of the robot's safety emergency stop circuit. The relays 104 arranged in series improve the safety of emergency stop control of the robot body 140, while the emergency stop branches 106, capable of data cross-checking, ensure the accuracy of emergency stop control. The combined effect enhances the safety protection level of the robot's safety emergency stop circuit, enabling the robot safety emergency stop circuit provided in this embodiment to meet Ple level requirements and be suitable for more complex application scenarios with higher safety performance requirements.

[0042] exist Figure 1In this example, two emergency stop branches 106 and two relays 104 are used. Optionally, the number of relays 104 and the number of emergency stop branches 106 can be matched, with each emergency stop branch 106 connected to a different relay 104, and each relay 104 connected to a different emergency stop branch 106. The number of relays 104 can also be greater than the number of emergency stop branches 106. Relays 104 not connected to an emergency stop branch 106 are called backup relays. When a relay 104 fails, the corresponding emergency stop branch 106 can be connected to a backup relay, enhancing the applicability and reliability of the robot's safety emergency stop circuit. When backup relays are present, they are all in a closed state.

[0043] In this embodiment, the robot safety emergency stop circuit includes an emergency stop switch 102, at least two relays 104, and at least two emergency stop branches 106. The first end of each emergency stop branch 106 is connected to the emergency stop switch 102, and the second end of each emergency stop branch 106 is connected to a different relay 104. The relays 104 are connected in series, with one end connected to a power supply 120 and the other end connected to the robot body 140. The emergency stop branch 106 is used to obtain the on / off state of the emergency stop switch 102 and control the on / off state of the relays 104 accordingly. By setting multiple emergency stop branches 106 to analyze the on / off state of the emergency stop switch 102, and then controlling the robot body 140 to perform emergency stop through the respective connected relays 104, a safe emergency stop can be achieved for the robot body 140 when any relay 104 is disconnected. This improves the safety performance of the robot safety emergency stop circuit and allows it to be applied to a wider range of scenarios.

[0044] In one embodiment, such as Figure 2 As shown, the emergency stop branch 106 includes a signal transmission circuit 202 and a controller 204. The signal transmission circuit 202 is connected to the emergency stop switch 102 and the controller 204, and the controller 204 is connected to the relay 104.

[0045] Specifically, the controller 204 obtains the on / off state of the emergency stop switch 102 through the signal transmission circuit 202, and controls the on / off state of the relay 104 accordingly. The signal transmission circuit 202 can receive on / off signals sent by the emergency stop switch 102, and the controller 204 receives these signals and analyzes them to obtain the on / off state of the emergency stop switch 102. Alternatively, the signal transmission circuit 202 can transmit detection signals sent by the controller 204 to the emergency stop switch 102 and receive feedback signals, allowing the controller 204 to analyze these feedback signals to obtain the on / off state of the emergency stop switch 102.

[0046] When there are two emergency stop branches 106 and two controllers 204, the robot safety emergency stop circuit is as follows: Figure 3 As shown. The controller 204 includes a first controller and a second controller; the signal transmission circuit 202 includes a first signal transmission circuit and a second signal transmission circuit; the relay 104 includes a first relay and a second relay; the first controller is connected to the first signal transmission circuit, the first relay, and the second controller; the second controller is connected to the second signal transmission circuit and the second relay; the emergency stop switch 102 is connected to the first signal transmission circuit and the second signal transmission circuit through different ports; the first relay is connected to the power supply 120 and the second relay; and the second relay is connected to the robot body 140.

[0047] In one embodiment, such as Figure 4 As shown, the signal transmission circuit 202 includes a signal transmitting circuit 402 and a signal receiving circuit 404, both of which are connected to the emergency stop switch 102 and the controller 204.

[0048] The controller 204 sends a detection signal to the emergency stop switch 102 via the signal sending circuit 402 and receives a feedback signal via the signal receiving circuit 404. By analyzing the difference between the detection signal and the feedback signal, the on / off state of the emergency stop switch 102 is determined. That is, when the emergency stop switch 102 is not triggered, it is equivalent to a short circuit, and the detection signal and the feedback signal should match. When the emergency stop switch 102 is triggered, it is equivalent to an open circuit, and the feedback signal is empty or zero.

[0049] Furthermore, the controllers 204 will transmit feedback signals to each other. That is, each controller 204 can analyze the detection signal and multiple feedback signals, and then obtain the result through logical judgment, thereby improving the accuracy of judging the on / off state of the emergency stop switch 102.

[0050] When there are two controllers 204, one is a RISC-V chip and the other is an ARM chip. These two chips are connected via an SPI bus to form a heterogeneous logic architecture, which can improve the system's common cause failure score. Each chip runs its own CPU, FLAH, RAM self-test programs and control logic. The feedback signal received by the signal receiving circuit 404 in the signal transmission circuit 202 is sampled by both chips through resistor isolation to determine whether the logic is normal. Finally, cross-detection is performed via the SPI bus, and the logic control is output to control the connected relay 104.

[0051] In one embodiment, such as Figure 5As shown, the signal transmission circuit 402 includes a high-level transmission unit 502 and a low-level transmission unit 504. The high-level transmission unit 502 is connected to the emergency stop switch 102, the controller 204 and the high-level power supply, and the low-level transmission unit 504 is connected to the emergency stop switch 102 and the controller 204 and is grounded.

[0052] The high-level transmitting unit 502 and the low-level transmitting unit 504 form a push-pull circuit. At any given time, only one of the high-level transmitting unit 502 and the low-level transmitting unit 504 will be turned on. That is, the signal transmitting circuit 402 will only output a high level or a low level at the same time, which will be sent to the emergency stop switch 102 as a detection signal.

[0053] Specifically, controller 204 controls the conduction state of high-level transmitting unit 502 and low-level transmitting unit 504, controlling the output of a high-level or low-level signal to emergency stop switch 102. When controller 204 controls high-level transmitting unit 502 to conduct, the high-level power supply transmits a high-level signal to emergency stop switch 102 via high-level transmitting unit 502. When controller 204 controls low-level transmitting unit 504 to conduct, low-level transmitting unit 504, being grounded, outputs a low-level signal to emergency stop switch 102.

[0054] Furthermore, in one embodiment, such as Figure 5 As shown, the signal transmission circuit 402 also includes an output drive circuit 506 and a fault feedback circuit 508. The output drive circuit 506 is connected to the controller 204, the input terminal of the high-level transmission unit 502 and the input terminal of the low-level transmission unit 504. The fault feedback circuit 508 is connected to the controller 204, the output terminal of the high-level transmission unit 502 and the output terminal of the low-level transmission unit 504.

[0055] Specifically, the controller 204 controls the switching on and off of the low-level transmitting unit 504 and the high-level transmitting unit 502 through the output drive circuit 506, thereby controlling the generation of high-level or low-level detection signals and outputting them to the emergency stop switch 102. The fault feedback circuit 508 is connected to the output terminals of the high-level transmitting unit 502 and the low-level transmitting unit 504, and is used to receive the detection signals output by the high-level transmitting unit 502 and the low-level transmitting unit 504 as the actual output signal, which is then transmitted to the controller 204. The controller 204 can analyze the actual output signal transmitted by the fault feedback circuit 508 and the detection signal to determine whether the actual output signal matches the detection signal expected by the controller 204. When the actual output signal matches the detection signal, the controller 204 determines that the high-level transmitting unit 502 and the low-level transmitting unit 504 are working normally and without abnormality. When the actual output signal does not match the detection signal, the controller 204 determines that the high-level transmitting unit 502 and the low-level transmitting unit 504 are malfunctioning and have a fault. The controller 204 can then generate a corresponding alarm message to indicate that the robot's emergency stop circuit is faulty and that there is a potential safety hazard.

[0056] Optionally, the detection signal can be a high-level signal, or a fluctuating signal consisting of high and low levels arranged in a certain pattern, such as a square wave signal. The fault feedback circuit 508 may include a transistor.

[0057] Furthermore, such as Figure 5 As shown, a first electrostatic discharge (ESD) protection circuit 510 can also be provided between the emergency stop switch 102 and the signal transmission circuit 402. The first ESD protection circuit 510 is used to protect the emergency stop switch 102. TVS (Transient Voltage Suppressors) transistors can usually be used as the main components of the first ESD protection circuit 510. TVS transistors can absorb large currents and control the voltage across them within a certain range, thus preventing the emergency stop switch 102 from being damaged by transient high-energy impacts.

[0058] In one embodiment, such as Figure 6 As shown, the high-level transmitting unit 502 includes a current sensing resistor 602, an overcurrent protection circuit 604, and a high-level output circuit 606. The current sensing resistor 602 is connected to the high-level power supply, the high-level output circuit 606, and the overcurrent protection circuit 604. The overcurrent protection circuit 604 is connected to the high-level power supply and the high-level output circuit 606. The high-level output circuit 606 is connected to the controller 204 and the emergency stop switch 102.

[0059] Specifically, the high-level output circuit 606 is connected to the controller 204, or connected to the controller 204 through the output drive circuit 506, and switches its operating state under the control of the controller 204. For example, the high-level output circuit 606 can be a PNP transistor, which can output a high-level power supply voltage. The current sensing resistor 602 is used to monitor the current flowing through the high-level output circuit 606, and at the same time generates a voltage drop that is transmitted to the overcurrent protection circuit 604. The overcurrent protection circuit 604 makes a judgment based on this voltage drop. When the voltage drop exceeds the threshold, the overcurrent protection circuit 604 cuts off the output of the high-level output circuit 606.

[0060] In one embodiment, the overcurrent protection circuit 604 is as follows: Figure 7 As shown, the circuit includes transistors Q1 and Q2, capacitors C1 and C2, and resistor R7. The input of transistor Q2 is connected to a high-level power supply (VCC, 24V) and one end of capacitor C2. The control terminal of transistor Q2 is connected to the other end of capacitor C2, resistor R7, and the input of transistor Q1. The output of transistor Q2 is connected to capacitor C1 and the control terminal of transistor Q1. The output of transistor Q1 is connected to capacitor C1 and the high-level output circuit 606. Resistor R7 is connected to current sensing resistor 602. Transistor Q2 is a PNP transistor, and transistor Q1 is an NPN transistor. Resistor R7 and capacitor C2 are used to adjust the sensitivity of the overcurrent protection circuit 604. Capacitors C1 and C2 are rated at 0.1 microfarads, and resistor R7 is rated at 10 kΩ.

[0061] Specifically, the voltage between points A and B is equal to the voltage drop across the current sensing resistor 602. Point B is connected to a high-level power supply, which is fixed at 24V; the voltage at point A varies with the current. When the current is too large, i.e., the voltage drop at point A is greater than 0.7V, transistor Q2 conducts, and current flows through transistor Q2 into the base of transistor Q1. Since transistors are current-controlled current sources, transistor Q1 also conducts, outputting an overcurrent signal. This overcurrent signal forms a stable current path through the high-level output circuit 606. If the output drive circuit 506 continuously sends a drive signal to the high-level output circuit 606, the overcurrent signal will continue to be output, achieving self-locking. If the drive circuit sends a shutdown signal, the output path of the overcurrent signal is cut off, and the overcurrent protection circuit 604 resets.

[0062] In one embodiment, the low-level transmitting unit 504 can have a similar structure to the high-level transmitting unit 502, such as... Figure 8As shown, the circuit includes transistors Q3 and Q4, capacitor C3, resistors R8 and R12. The output drive circuit 506 is connected to the control terminal of transistor Q4, resistor R12, and the input terminal of transistor Q3. The output terminal of transistor Q3, along with resistors R12, R8, and capacitor C3, is grounded. The control terminal of transistor Q3 is connected to resistors R8, capacitor C3, and the output terminal of transistor Q4. The input terminal of transistor Q4 is connected to the emergency stop switch 102. Transistors Q3 and Q4 are both NPN transistors. Capacitor C3 is rated at 0.1 microfarads, resistor R12 is rated at 10 kΩ, and resistor R8 is rated at 3.3 ohms.

[0063] The current sensing resistor in the low-level transmitting unit 504 is resistor R8. The overcurrent protection circuit includes transistor Q3 and capacitor C3, and the low-level output circuit includes transistor Q4 and resistor R12. The overcurrent protection circuit is a current-limiting circuit, and transistor Q4 is the output transistor. When there is an overcurrent, the current sensing resistor generates a voltage drop, which turns on transistor Q3, pulls down the input signal of transistor Q4, and reaches a balance state, thus achieving current-limited output.

[0064] It is important to note that, in Figure 7 and Figure 8 The current limiting values ​​of the high-level output circuit 606 and the low-level output circuit are different. The current limiting value of the high-level output circuit 606 is 50mA and has a self-locking function; the current limiting value of the low-level output circuit is 100mA and has no self-locking function.

[0065] In this embodiment, by setting a high-level transmitting unit 502 and a low-level transmitting unit 504, the output value of the signal transmitting circuit 402 can be changed. This, combined with multiple emergency stop branches 106, allows for the output of different detection signals. For example, one emergency stop branch 106 outputs a high level, while another outputs a low level. By using different detection signals from different emergency stop branches 106, the on / off state of the emergency stop switch 102 can be analyzed, ensuring the accuracy of obtaining the on / off state.

[0066] In one embodiment, such as Figure 9 As shown, the signal receiving circuit 404 includes a signal sampling circuit 702 and a signal modulation circuit 704. The signal sampling circuit 702 is connected to the controller 204 and the signal modulation circuit 704, and the signal modulation circuit 704 is connected to the emergency stop switch 102. The signal sampling signal may include a transistor and a pull-up resistor.

[0067] Specifically, the signal receiving circuit 404 receives feedback signals and analyzes the on / off state of the emergency stop switch 102 based on these feedback signals. The signal modulation circuit 704 adjusts the received signals, including but not limited to adjusting voltage and current, or filtering the signals to avoid damage to subsequent devices. The signal sampling circuit 702 acquires the signals and transmits them to the controller 204 as the received feedback signals.

[0068] Furthermore, such as Figure 9 As shown, the signal receiving circuit 404 also includes a self-test circuit 708. The self-test circuit 708 is connected to the output of the signal modulation circuit 704 and the controller 204. It is used to acquire and sample the signal output by the signal modulation circuit 704, and then feed the sampled signal back to the controller 204. When there are two controllers 204, one is a RISC-V chip and the other is an ARM chip. These two chips are connected via an SPI bus to form a heterogeneous logic architecture, which can improve the common cause failure score of the system. Each chip runs its own CPU, FLAH, RAM self-test program and control logic. The sampled signal from the self-test circuit 708 in the signal transmission circuit 202 is sampled by the two chips through resistor isolation, and the logic is judged to be normal. Finally, cross-detection is performed via the SPI bus, and then the logic control is output to control the connected relay 104.

[0069] Furthermore, such as Figure 9 As shown, the signal modulation circuit 704 includes a voltage limiting circuit 7042 and a resistor voltage divider circuit 7044. The resistor voltage divider circuit 7044 is connected to the emergency stop switch 102 and the voltage limiting circuit 7042, and the voltage limiting circuit 7042 is connected to the signal sampling circuit 702. The voltage limiting circuit 7042 can be a Zener diode, and the resistor voltage divider circuit 7044 can include a current-limiting resistor and a voltage-dividing resistor.

[0070] Specifically, the signal is divided in the resistor voltage divider circuit 7044. To match the 0.7V conduction characteristic of the transistor in the signal sampling circuit 702, the resistor voltage divider circuit 7044 is designed to output a 0.7V signal when the input signal exceeds 7V, enabling the signal sampling circuit 702 to conduct and indicating the receipt of a high-level signal. The voltage limiting circuit 7042 limits the output voltage of the resistor voltage divider circuit 7044 to within 3.3V to prevent spike pulses exceeding 5V from damaging the base of the transistor in the signal sampling circuit 702. The self-test circuit 708 sends a self-test signal. When enabled, it can change the output value of the resistor voltage divider circuit 7044, thereby changing the level in the sampled value of the signal sampling circuit 702. The controller 204 can detect whether the circuit components in the signal sampling circuit 702 are damaged by the level of the received self-test signal.

[0071] Optionally, such as Figure 9 As shown, a second electrostatic discharge (ESD) protection circuit 706 can also be provided between the emergency stop switch 102 and the signal receiving circuit 404. The second ESD protection circuit 706 is used to protect the signal receiving circuit 404. TVS (Transient Voltage Suppressors) transistors are usually used as the main components of the second ESD protection circuit 706. TVS transistors can absorb large currents and control the voltage across them within a certain range, thus preventing the signal receiving circuit 404 from being damaged by transient high-energy impacts.

[0072] In this embodiment, by conditioning the feedback signal in the signal receiving circuit 404, the feedback signal is accurately obtained while ensuring the reliability of the signal receiving circuit 404, so that the controller 204 can analyze the on / off state of the emergency stop switch 102.

[0073] In one embodiment, the robot safety emergency stop circuit also includes a relay detection circuit, which is connected to both ends of the series-connected relays 104 and is used to detect whether each relay 104 is functioning properly.

[0074] The relay 104 is a conversion type, and multiple relays 104 are connected in series to jointly control the power supply of the robot body 140. When one controller 204 is a RISC-V chip and the other controller 204 is an ARM chip, the controller 204 can control the relay 104 through a relay drive circuit. The relay drive circuit is a constant current source, with an output voltage of 24V and a current limit of 50mA at startup. After the relay 104 starts, it maintains a current of 13.5mA to control the coil heating of the relay 104 and prevent the coil from burning out during operation. The relay detection circuit is connected across the series-connected relays 104 to detect whether the relay 104 is functioning properly and whether the coil has burned out.

[0075] In one embodiment, such as Figure 10 As shown, the relay detection circuit includes a push-pull output circuit 802 and a square wave receiving circuit 804. The push-pull output circuit 802 is connected to one end of the relay 104 connected in series, and the square wave receiving circuit 804 is connected to the other end of the relay 104 connected in series.

[0076] Specifically, the push-pull output circuit 802 is connected to one end of the series-connected relay 104 to generate square wave pulses and send them to the series-connected relay 104. When the relay 104 is fault-free, the square wave receiving circuit 804 can receive complete, uninterrupted square wave pulses; when the relay 104 malfunctions, the received square wave pulses will be intermittent.

[0077] Taking relay 104, which includes a first relay and a second relay, as an example, the detection process is as follows when relay 104 is in normal condition: 1. Turn off both the first and second relays 104. The push-pull output circuit 802 continuously sends square wave pulses, and the square wave receiving circuit 804 samples and receives 50 pulses. 2. Turn on the first relay and turn off the second relay. Within 50ms, the square wave receiving circuit 804 receives no pulses. 3. Turn off both the first and second relays. The push-pull output circuit 802 continuously sends square wave pulses, and the square wave receiving circuit 804 samples and receives 50 pulses. 4. Turn off the first relay and turn on the second relay. Within 50ms, the square wave receiving circuit 804 receives no pulses. 5. It is determined that relay 104 is normal.

[0078] Furthermore, such as Figure 10 As shown, the relay detection circuit may further include multiple TVS circuits and multiple safety capacitors respectively disposed across the two ends of the series-connected relay 104. The safety capacitors are connected in series between the push-pull output circuit 802 and the square wave receiving circuit 804. The TVS circuits are disposed at the common terminal of the push-pull output circuit 802 and the safety capacitors, and at the common terminal of the square wave receiving circuit 804 and the safety capacitors. If the relay 104 is normally closed and no sticking occurs, the push-pull output circuit 802 sends a square wave pulse using the principle of capacitor blocking DC and passing AC. The pulse can be sampled by the square wave receiving circuit 804 through the safety capacitors and the relay 104. If sticking occurs, or if the relay drive circuit fails, the relay 104 is normally open, and the square wave receiving circuit 804 receives no signal.

[0079] In this embodiment, by setting up a relay detection circuit, the working status of relay 104 is detected, relay 104 faults are detected in a timely manner, safety hazards caused by relay 104 faults are reduced, and the reliability of the robot's emergency stop circuit is ensured.

[0080] Based on the same technical concept, this application also provides a robot safety emergency stop system, including a robot body 140, a power supply 120, and a robot safety emergency stop circuit as described in the above embodiments. The robot safety emergency stop circuit connects the robot body 140 and the power supply 120. The power supply 120 supplies power to the robot body 140 through the robot safety emergency stop circuit. When the robot safety emergency stop circuit performs emergency stop control, it disconnects the connection between the power supply 120 and the robot body 140, and the robot body 140 is de-energized.

[0081] To better understand the above solution, a detailed explanation will be provided below with reference to a specific embodiment.

[0082] In one embodiment, a robot safety emergency stop system is provided, including a robot body, a power supply, and a robot safety emergency stop circuit. The robot safety emergency stop circuit includes an emergency stop switch, a relay detection circuit, at least two relays, and at least two emergency stop branches.

[0083] The emergency stop branch includes a signal transmission circuit and a controller. The signal transmission circuit includes a signal transmitting circuit and a signal receiving circuit. When there are two emergency stop branches, there are also two controllers: a first controller and a second controller. One controller is a RISC-V chip, and the other is an ARM chip. The signal transmission circuit includes a first signal transmission circuit and a second signal transmission circuit. The first signal transmission circuit includes a first signal transmitting circuit and a second signal receiving circuit. The first signal transmitting circuit is connected to the first controller and the emergency stop switch through port 11, and the first signal receiving circuit is connected to the first controller and the emergency stop switch through port 12. The second signal transmission circuit includes a second signal transmitting circuit and a second signal receiving circuit. The second signal transmitting circuit is connected to the second controller and the emergency stop switch through port 21, and the second signal receiving circuit is connected to the second controller and the emergency stop switch through port 22.

[0084] The signal transmission circuit includes a high-level transmission unit, a low-level transmission unit, a first electrostatic discharge (ESD) protection circuit, an output drive circuit, and a fault feedback circuit. The high-level transmission unit includes a current-sensing resistor, an overcurrent protection circuit, and a high-level output circuit. The circuit diagram of the overcurrent protection circuit is shown below. Figure 7 As shown above, this will not be repeated here.

[0085] The signal receiving circuit includes a signal sampling circuit, a signal modulation circuit, a self-test circuit, and a second electrostatic discharge (ESD) protection circuit. The signal modulation circuit includes a voltage limiting circuit and a resistor divider circuit. The relay detection circuit includes a push-pull output circuit, a square wave receiving circuit, a TVS circuit, and a safety capacitor, such as... Figure 10 As shown above, this will not be repeated here.

[0086] In this embodiment, by setting up multiple circuits for self-testing and detection, the self-test coverage is high, and various fault conditions can be detected. The controller of this application uses a heterogeneous architecture scheme, which can effectively prevent common-cause failures. This application also uses discrete component design for redundant backup circuits to meet high-specification system requirements, achieve PLe-level safety protection, and make the robot's emergency stop circuit applicable to more application scenarios.

[0087] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative descriptions of the above terms do not necessarily refer to the same embodiments or examples.

[0088] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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 specification.

[0089] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these modifications and improvements all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A robot safety emergency stop circuit, characterized in that, It includes an emergency stop switch, at least two relays, and at least two emergency stop branches. The first end of each emergency stop branch is connected to the emergency stop switch, and the second end of each emergency stop branch is connected to a different relay. The relays are connected in series, with one end of the series connection used to connect to the power supply and the other end of the series connection used to connect to the robot body. The emergency stop branch is used to obtain the on / off state of the emergency stop switch and control the on / off state of the relay accordingly. The emergency stop branch includes a signal transmission circuit and a controller. The signal transmission circuit is connected to the emergency stop switch and the controller, and the controller is connected to the relay. The controller obtains the on / off state of the emergency stop switch through the signal transmission circuit and controls the on / off state of the relay accordingly. The signal transmission circuit includes a signal transmitting circuit and a signal receiving circuit, both of which are connected to the emergency stop switch and the controller. The signal transmitting circuit includes a high-level transmitting unit and a low-level transmitting unit. The high-level transmitting unit is connected to the emergency stop switch, the controller, and a high-level power supply, while the low-level transmitting unit is connected to the emergency stop switch and the controller and is grounded.

2. The robot safety emergency stop circuit according to claim 1, characterized in that, The signal transmission circuit further includes an output driving circuit and a fault feedback circuit. The output driving circuit is connected to the controller, the input terminal of the high-level transmission unit, and the input terminal of the low-level transmission unit. The fault feedback circuit is connected to the controller, the output terminal of the high-level transmission unit, and the output terminal of the low-level transmission unit.

3. The robot safety emergency stop circuit according to claim 1, characterized in that, The high-level transmitting unit includes a current-sensing resistor, an overcurrent protection circuit, and a high-level output circuit. The current-sensing resistor is connected to the high-level power supply, the high-level output circuit, and the overcurrent protection circuit. The overcurrent protection circuit is connected to the high-level power supply and the high-level output circuit. The high-level output circuit is connected to the controller and the emergency stop switch.

4. The robot safety emergency stop circuit according to claim 1, characterized in that, The signal receiving circuit includes a signal sampling circuit and a signal modulation circuit. The signal sampling circuit is connected to the controller and the signal modulation circuit, and the signal modulation circuit is connected to the emergency stop switch.

5. The robot safety emergency stop circuit according to claim 1, characterized in that, The robot safety emergency stop circuit also includes a relay detection circuit, which is connected to both ends of the relays connected in series and is used to detect whether each relay is functioning properly.

6. The robot safety emergency stop circuit according to claim 5, characterized in that, The relay detection circuit includes a push-pull output circuit and a square wave receiving circuit. The push-pull output circuit is connected to one end of the relay connected in series, and the square wave receiving circuit is connected to the other end of the relay connected in series.

7. A robot safety emergency stop system, characterized in that, It includes a robot body, a power supply, and a robot safety emergency stop circuit as described in any one of claims 1-6, wherein the robot safety emergency stop circuit is connected to the robot body and the power supply.

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