Relay safety system and robotic arm controller

Abstract

A relay safety system includes a relay, an emergency stop device, a trigger detection circuit, a contact sticking detection circuit, and a power-off circuit. The emergency stop device is used to generate an emergency stop signal. The trigger detection circuit is connected to the relay and the emergency stop device, and is used to convert the emergency stop signal into a trigger signal. The contact sticking detection circuit is connected to the trigger detection circuit and the relay, and is used to detect the contact sticking signal generated by the relay, and generate a power-off signal according to the trigger signal and the contact sticking signal. The power-off circuit is connected to the emergency stop device, the relay, and the contact sticking detection circuit, and receives the power-off signal, and disconnects the power supply of the relay according to the power-off signal.

Description

Technical Field

[0001] The present invention relates to a controller of electromechanical equipment, and particularly to a robotic arm controller and a relay safety system. Prior Art

[0002] Relays are widely used in the field of automatic control, such as robotic arms, mechanical equipment, or other electromechanical equipment. However, the mechanical contacts of relays will cause the normally open contacts and the common contacts to stick together due to factors such as the operating temperature and electrical conditions, resulting in a stuck point or dead suction state.

[0003] Taiwan, China New Patent No. M472196 discloses a relay contact fault detection system, which triggers the control system to issue an alarm through the design of the control loop unit and does not allow the control system to be restarted again. Another embodiment is to disconnect the power of the internal control low-voltage source through the protection loop unit. Therefore, this patent needs to detect the status of the relay at any time and cut off the operation of the high-voltage power supply by cutting off the transmission of the internal control low-voltage source, and cannot separately cut off the transmission paths of the internal control low-voltage source and the high-voltage power supply. However, it gives an alarm to prohibit the next start when one of the two relays has a contact abnormality and cannot directly disconnect the power supply of the relay. In addition, if both relays have abnormalities at the same time, this patent does not give a solution instruction.

[0004] China Patent No. CN101427335 discloses a power control device and an abnormal detection method for a relay, which judges the status of the relay through the charging plan of a capacitive element.

[0005] China Publication No. CN109216113A discloses a relay device, which sets a control unit inside the relay. The control unit includes a fault detection unit and a switching control unit. This method requires re-designing the relay structure and, due to the addition of the control unit, the volume should be larger than that of a general relay, which is not conducive to being installed in a controller with limited space. Summary of the Invention

[0006] In view of the above-mentioned deficiencies, one of the objectives of the present invention is to provide a relay safety system and a robotic arm controller applying the relay safety system, which can disconnect the relevant power supply of the relay when the relay has a contact abnormality, so as to improve the safety of relay use.

[0007] The relay safety system provided by the present invention includes a relay, an emergency stop device, a trigger detection circuit, a sticking point detection circuit, and a power-off circuit. The emergency stop device is used to generate an emergency stop signal. The trigger detection circuit is connected to the relay and the emergency stop device, and is used to convert the emergency stop signal into a trigger signal. The sticking point detection circuit is connected to the trigger detection circuit and the relay, and is used to detect the sticking point signal generated by the relay, and generate a power-off signal according to the trigger signal and the sticking point signal. The power-off circuit is connected to the emergency stop device, the relay, and the sticking point detection circuit, and receives the power-off signal, and disconnects the power supply of the relay according to the power-off signal.

[0008] The present invention provides a robotic arm controller including a relay safety system.

[0009] The relay safety system of the present invention and the robotic arm controller applying the relay safety system can use the emergency stop signal generated by the emergency stop device to make the trigger detection circuit drive the sticking point detection circuit to judge whether there is an abnormal sticking point of the relay, and when there is an abnormal sticking point, disconnect the relevant power supply of the relay through the power-off circuit to improve the safety of relay use. In addition, through the emergency stop device, it is also possible to detect whether there is an abnormal sticking point of the relay to improve the reliability of relay use. Description of the Drawings

[0010] The detailed structure, characteristics, and manufacturing method of the relay safety system will be described in the following embodiments. It should be understood that the embodiments and drawings to be described below are only for illustrative purposes and should not be used to limit the scope of the patent application of the present invention, where:

[0011] Figure 1 is a schematic block diagram of the composition of the relay safety system of the present invention.

[0012] Figure 2 is a continuation of Figure 1 the hardware circuit diagram of the relay safety system in Detailed Embodiments

[0013] The following will detail the technical content and features of the present invention through a number of enumerated embodiments in conjunction with the drawings. The terms "connected" or "electrically connected" mentioned in the content of this specification are only terms for normal electrical conduction or connection formation, and are not intended to limit the scope of the claim. Also, the descriptive terms such as "high input" or "low input", "high output" or "low output" of electrical signal levels or levels mentioned in the content of the specification are only illustrative descriptive terms for normal formation of high and low electrical signal references, and are not intended to limit the scope of the claim.

[0014] In order to detail the technical features of the present invention, the following embodiments are now given and described in conjunction with the drawings as follows, where:

[0015] As inFigure 1 As shown, the relay safety system 10 of the present invention is applied to a robotic arm controller or other environments that require relays.

[0016] The relay safety system 10 includes a relay 11, an emergency stop device 13, a trigger detection circuit 15, a contact adhesion detection circuit 17, and a power-off circuit 19. The relay 11 includes a coil 111, a normally open contact 113, a normally closed contact 115, and a common contact 117. The emergency stop device 13 is used to generate an emergency stop signal. Among them, the trigger detection circuit 15, the contact adhesion detection circuit 17, and the power-off circuit 19 are arranged on a circuit board (not shown in the figure).

[0017] The trigger detection circuit 15 is connected to the coil 111 of the relay 11 and the emergency stop device 13, and is used to receive the emergency stop signal. The contact adhesion detection circuit 17 is connected to the trigger detection circuit 15 and the normally closed contact 115 of the relay 11, and is used to generate a power-off signal according to the emergency stop signal and the contact signal of the relay 11. The power-off circuit 19 is connected to the contact adhesion detection circuit 17, the relay 11, and the emergency stop device 13, and disconnects the power supply of the relay 11 according to the power-off signal.

[0018] During normal power supply operation, the relay 11 can supply power to the load through the conduction of the normally open contact 113 and the common contact 117. At this time, the normally closed contact 115 and the common contact 117 are disconnected and not connected. When performing power-off operation under normal conditions, the normally closed contact 115 of the relay 11 and the common contact 117 are conducted, and the normally open contact 113 and the common contact 117 will be disconnected and not connected, so power cannot be supplied to the load 30. The load 30 is, for example, other circuits or motors of a robotic arm controller.

[0019] When it is found that the relay 11 is abnormal, both the normally open contact 113 and the common contact 117 of the relay 11 are closed, that is, the normally open contact 113 and the common contact 117 are in a stuck or adhered state. Similarly, the normally closed contact 115 and the common contact 117 are in a non-conducted state. In this way, the relay 11 will not be able to effectively cut off the power supply to the load.

[0020] In this abnormal situation, the present invention detects the state of the emergency stop signal through the trigger detection circuit 15. After the trigger detection circuit 15 detects the emergency stop signal, the trigger detection circuit 15 converts the emergency stop signal into a trigger signal and transmits the trigger signal to the contact adhesion detection circuit 17. The contact adhesion detection circuit 17 operates according to the trigger signal to detect the contact state of the relay 11.

[0021] In this embodiment, the sticking point detection circuit 17 detects the operating state of the normally closed contact 115. When there is an emergency stop signal and the normally closed contact 115 and the common contact 117 are in the open state, it indicates an abnormal state where the normally open contact of the relay is stuck or adhered. This abnormal state is called a sticking point. Subsequently, the sticking point detection circuit 17 generates a power-off signal, and the power-off circuit 19 disconnects the power supply of the relay 11 according to the power-off signal for inspection and repair operations.

[0022] In addition, when there is an emergency stop signal, but the normally closed contact 115 and the common contact 117 are in the connected state, it indicates that the relay 11 is still normal.

[0023] In this embodiment, the power-off circuit 19 includes a first switch unit 191 and a second switch unit 193. The first switch unit 191 is connected to the first power supply V S1 and the emergency stop device 13, and is used to disconnect the power supply to the emergency stop device 13 according to the power-off signal. The second switch unit 193 is connected to the second power supply V S2 and the normally open contact 113, and is used to disconnect the power supply to the normally open contact 113 of the relay 11 according to the power-off signal, and disconnect the related power supply of the relay 11 to achieve the purpose of power-off.

[0024] Continuing the above normal state, when the sticking point detection circuit 17 detects that the normally closed contact 115 and the common contact 117 are in the open state, it indicates that the stuck or adhered state has been released. Therefore, the relay 11 is normal and no power-off signal will be generated.

[0025] As Figure 2 shown, Figure 2 is a continuation of Figure 1 the embodiment, but the difference is that two relays 11 are applied. In other words, in other embodiments, the number of relays can be more, such as three or more.

[0026] The emergency stop device 13 includes a fuse 131 and an emergency stop switch unit 133 connected to the fuse 131. The emergency stop switch unit 133 is used to actuate or trigger to generate an emergency stop signal. However, in other embodiments, the emergency stop device 13 can also generate an emergency stop signal through other components or electronic circuits.

[0027] The trigger detection circuit 15 includes an input protection unit 151, a first operational amplifier OPA1, and a second operational amplifier OPA2. The sticking point detection circuit 17 includes a first N-channel transistor (N-MOSFET) Q1 and operates according to the trigger signal. The power-off circuit 19 includes an optocoupler 195, a second N-channel transistor Q2, a first P-channel transistor (P-MOSFET) Q3, a second P-channel transistor Q4, and an output protection unit 197. Among them, the first switch unit 191 and the second switch unit 193 are the first P-channel transistor Q3 and the second P-channel transistor Q4 respectively.

[0028] The input protection unit 151 is electrically connected to the output terminal V of the emergency stop device 13 D (i.e., the emergency stop switch unit 133 of the emergency stop device 13) and the inverting input terminal of the first operational amplifier OPA1. The non-inverting input terminal of the first operational amplifier OPA1 is electrically connected to the first power supply V S1 , and the output terminal of the first operational amplifier OPA1 is electrically connected to the inverting input terminal of the second operational amplifier OPA2. The non-inverting input terminal of the second operational amplifier OPA2 is electrically connected to the first power supply V S1 . The output terminal of the second operational amplifier OPA2 is electrically connected to the gate of the first N-channel transistor Q1. The source of the first N-channel transistor Q1 is connected to the ground terminal. The drain of the first N-channel transistor Q1 is electrically connected to the normally closed contact 115 of the relay, the first power supply V S1 , the gate of the second N-channel transistor Q2, and the gate of the first P-channel transistor Q3. The source of the second N-channel transistor Q2 is electrically connected to the ground terminal. The source of the first P-channel transistor Q3 is electrically connected to the first power supply V S1 , the output protection unit 197 is electrically connected to the drain of the first P-channel transistor Q3 and the input terminal of the emergency stop device 13, i.e., the fuse 131 of the emergency stop device 13. The primary side of the optocoupler 195 is electrically connected to the first power supply V S1 and the drain of the second N-channel transistor Q2. The secondary side of the optocoupler 195 is electrically connected to the second power supply V S2 and the gate of the second P-channel transistor Q4. The source of the second P-channel transistor Q4 is electrically connected to the second power supply V S2 , the drain of the second P-channel transistor Q4 is electrically connected to the normally open contact 113 of the relay 11. The output terminal V of the emergency stop switch 13 D is electrically connected to the coil 111 of the relay 11.

[0029] In this embodiment, the input protection unit 151 and the output protection unit 197 have the same composition, which includes a diode and a transient conduction diode. Thus, through the settings of the input protection unit 151 and the output protection unit 197, it is possible to avoid damage to the power supply system (i.e., the second power supply V S2 and the first power supply V S1 ) caused by incorrect wiring of the second power supply V S2 and the first power supply V S1 power supply environment).

[0030] Under normal or regular power supply conditions, the normally open contact 113 of relay 11 is connected to the common contact 117, and the normally closed contact 115 is open, allowing power supply to the load. At this time, when the emergency stop device 13 is not actuated or triggered, the emergency stop device 13 provides a high output to the inverting input terminal of the first operational amplifier OPA1, causing the output terminal of the first operational amplifier OPA1 to be a low output and the output of the second operational amplifier OPA2 to be a high output. Thus, the first N-channel transistor Q1 is in a conducting state, that is, the drain-source of the first N-channel transistor Q1 is conducting, and the drain of the first N-channel transistor Q1 is a low output. At this time, the gates of the second N-channel transistor Q2, the first P-channel transistor Q3, and the second P-channel transistor Q4 are low inputs, causing the second N-channel transistor Q2 to be cut off, and the first P-channel transistor Q3 and the second P-channel transistor Q4 to be in a conducting state, and continuously supplying power to the relay 11.

[0031] When the emergency stop device 13 is actuated or triggered, the emergency stop device 13 provides a low output to the inverting input terminal of the first operational amplifier OPA1, causing the output terminal of the first operational amplifier OPA1 to be a high output and the output of the second operational amplifier OPA2 to be a low output, causing the first N-channel transistor Q1 to be cut off, and the normally closed contact 115 of the relay 11 to be connected to the common contact 117, that is, the relay 11 is normal. Therefore, the first P-channel transistor Q3 and the second P-channel transistor Q4 are in a conducting state, and power can continue to be supplied to the relay.

[0032] When the emergency stop device 13 is actuated or triggered, the emergency stop device 13 provides a low output to the inverting input terminal of the first operational amplifier OPA1, causing the output terminal of the first operational amplifier OPA1 to be a high output and the output of the second operational amplifier OPA2 to be a low output. The first N-channel transistor Q1 is cut off, and the normally closed contact 115 of the relay 11 is not connected to the common contact 117, indicating that the normally open contact 113 and the common contact 117 may be in a sticking state, that is, the relay 11 is abnormal. At this time, the gates of the first P-channel transistor Q3 and the second N-channel transistor Q2 are high inputs, causing the second N-channel transistor Q2 to be conducting, resulting in the operation of the optocoupler 195, so that the gate of the second P-channel transistor Q4 is a high input, and the first P-channel transistor Q3 and the second P-channel transistor Q4 are in a cut-off (or non-conducting) state to disconnect the transmission paths of the second power supply V S2 and the first power supply V S1 of.

[0033] In the power-off circuit 19, the optocoupler 195 is used to control the gate voltage of the second P-channel transistor Q4 through the first power supply V S1 so that the power-off circuit 19 can effectively synchronously switch the first P-channel transistor Q3 and the second P-channel transistor Q4. Also, the optocoupler 195 can effectively isolate the first power supply VS1 and the second power supply V S2 to avoid the influence between the first power supply V S1 and the second power supply V S2 from affecting each other.

[0034] In this way, the relay safety system of the present invention can give an emergency stop request through the emergency stop signal of the emergency stop device, and confirm whether there is an abnormality in the relay, that is, the sticking problem, by triggering the detection circuit and the contact sticking detection circuit. When an abnormality exists, the relevant power supplies of all relays are disconnected through the power-off circuit. The robotic arm controller can disconnect the power supply of the relay through the relay safety system to repair, maintain or replace the relay of the robotic arm.

[0035] Through the above embodiments, those skilled in the art can understand the technology and purpose of the hardware configuration of the relay safety system of the present invention. Therefore, the above configurations of the operational amplifier and the transistor (including N-channel transistor or P-channel transistor) can also be changed through the arrangement of the number or logic elements in the hardware to achieve the same technology and purpose. Therefore, the operational amplifier and the transistor described in the embodiments are only for the description in this embodiment, and are not intended to limit the scope of the claim.

[0036] Symbolic description

[0037] 10: Relay safety system

[0038] 11: Relay

[0039] 111: Coil

[0040] 113: Normally open contact

[0041] 115: Normally closed contact

[0042] 117: Common contact

[0043] 13: Emergency stop device

[0044] 131: Fuse

[0045] 133: Emergency stop switch unit

[0046] 15: Trigger detection device

[0047] 151: Input protection unit

[0048] 17: Contact sticking detection device

[0049] 19: Power-off circuit

[0050] 191: First switch unit

[0051] 193: Second switch unit

[0052] 195: Optical coupler

[0053] 197: Output protection unit

[0054] 30: Load

[0055] OPA1: First operational amplifier

[0056] OPA2: Second operational amplifier

[0057] Q1: First N-channel transistor

[0058] Q2: Second N-channel transistor

[0059] Q3: First P-channel transistor

[0060] Q4: Second P-channel transistor

[0061] V S1 : First power supply

[0062] V S2 : Second power supply

[0063] V D : Output terminal

Claims

1. A relay safety system, comprising: a relay; an emergency stop device for generating an emergency stop signal; a trigger detection circuit connected to the relay and the emergency stop device and for converting the emergency stop signal into a trigger signal; a contact sticking detection circuit connected to the trigger detection circuit and the relay and for detecting a contact sticking signal generated by the relay and generating a power-off signal based on the trigger signal and the contact sticking signal; and a power-off circuit connected to the emergency stop device, the relay and the contact sticking detection circuit, receiving the power-off signal, and disconnecting the power supply of the relay based on the power-off signal, wherein the power-off circuit includes a first switch unit and a second switch unit, the first switch unit is electrically connected to the emergency stop device and a first power supply, the second switch unit is electrically connected to the normally open contact of the relay and a second power supply, and the power-off circuit controls the first switch unit and the second switch unit to be in a cut-off state based on the power-off signal, wherein the trigger detection circuit includes a first operational amplifier and a second operational amplifier, the inverting input terminal of the first operational amplifier is electrically connected to the emergency stop device, the non-inverting input terminal of the first operational amplifier is electrically connected to the first power supply, the output terminal of the first operational amplifier is electrically connected to the inverting input terminal of the second operational amplifier, the non-inverting input terminal of the second operational amplifier is electrically connected to the first power supply, and the output terminal of the second operational amplifier is electrically connected to the contact sticking detection circuit.

2. The relay safety system according to claim 1, wherein, the power-off circuit includes an optocoupler and a transistor, the primary side of the optocoupler is electrically connected to the first power supply and the transistor of the power-off circuit, the secondary side of the optocoupler is electrically connected to the second power supply and the second switch unit, and the power-off circuit controls the transistor of the power-off circuit to conduct based on the power-off signal.

3. The relay safety system according to claim 2, wherein, the contact sticking detection circuit includes a transistor connected to the normally closed contact of the relay, the trigger detection circuit and the power-off circuit and being cut off based on the trigger signal.

4. The relay safety system according to claim 3, wherein, when the contact sticking detection circuit does not receive the trigger signal, the transistor of the contact sticking detection circuit is conducting.

5. The relay safety system according to claim 1, wherein, the power-off circuit includes an output protection unit connected to the first switch unit and the emergency stop device.

6. The relay safety system according to claim 1, wherein, the trigger detection circuit includes an input protection unit connected to the emergency stop device and the inverting input terminal of the first operational amplifier.

7. A robotic arm controller comprising the relay safety system according to any one of claims 1 to 6.

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