Permanent magnet brake and control method thereof

Abstract

The invention provides a permanent magnet brake and a control method thereof. The control method of the permanent magnet brake comprises the following steps that the control unit receives an instruction and judges the type of the instruction; if the instruction is a release instruction, the voltage power supply module applies release voltage U1 to the excitation winding; the current acquisition module acquires the real-time current of the excitation winding and calculates the current change slope; when the current change slope is smaller than or equal to a set first change slope, determining that the permanent magnet brake finishes releasing; if the command is a braking command, the voltage power supply module applies a braking voltage U2 to the excitation winding; the voltage acquisition module acquires the real-time induced voltage of the excitation winding and calculates the change slope of the induced voltage; and when the induced voltage change slope is smaller than or equal to a set second change slope, it is determined that the permanent magnet brake completes braking. According to the permanent magnet brake and the control method thereof, the brake structure and method are optimized, and safety and response performance are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile braking, and in particular to a permanent magnet brake and a control method thereof. Background Art

[0002] Currently, electromagnetic brakes are generally controlled by setting a predetermined voltage or current target on the coil winding to achieve desired state control of the excitation winding portion of the electromagnetic brake.

[0003] In the existing technology, only fixed parameter boundaries with a large margin are obtained through overall product performance data or test data, and the unified control parameters are used to control the winding circuit of the electromagnetic brake. Signal acquisition or status judgment of the actual electromagnetic brake structure is not performed, and it is impossible to determine whether the release and engagement of the electromagnetic brake are truly achieved. In addition, the parameter control of the predetermined voltage or current target cannot cover performance fluctuations caused by product production differences, environmental impacts, wear and aging, etc. The control has a failure range, control lag, and energy consumption cannot be optimized, which reduces the speed, safety, reliability, and economy of the product control. For users, it will also cause practical problems such as performance waste, high failure rate, short service life, and high power consumption. Summary of the Invention

[0004] An embodiment of the present invention provides a permanent magnet brake and a control method thereof, which optimizes the braking structure and controls the magnetic conductive component through the total magnetic field of the permanent magnet and the excitation winding, thereby realizing the braking and release of the permanent magnet brake. The permanent magnet brake utilizes the influence of the movement of the structural components on the voltage and current characteristics of the excitation winding during the release and braking process, and confirms the state of the permanent magnet brake through the changes in the voltage and current slope of the excitation winding, thereby improving the safety performance and response performance.

[0005] A permanent magnet brake provided by an embodiment of the present invention includes a brake unit and a control unit, wherein the brake unit includes a rotating component and a fixed component coaxially sleeved on a transmission shaft, the rotating component rotates with the transmission shaft, the fixed component is fixedly connected to the vehicle body, the fixed component includes a fixing part, an excitation winding and a permanent magnet, and the excitation winding and the permanent magnet are installed on the fixing part; the control unit is connected to the excitation winding, and the control unit includes a voltage power supply module, a current acquisition module and a voltage acquisition module; the voltage power supply module outputs voltage to the excitation winding, the current acquisition module acquires the current of the excitation winding, and the voltage acquisition module acquires the current of the excitation winding. induced voltage; the rotating component includes a sleeve, a release member and a magnetic member, the sleeve is fixedly mounted on the transmission shaft, the release member and the magnetic member are arranged side by side outside the sleeve, the release member is fixedly connected to the sleeve, the magnetic member is movably connected to the sleeve, the sleeve allows the magnetic member to move axially along the sleeve and prevents the magnetic member from rotating relative to the sleeve, and an elastic member is arranged between the magnetic member and the release member; the fixed component is mounted outside the sleeve and is located at one end close to the magnetic member, and a rolling member is arranged between the fixed component and the sleeve, and the rolling member allows the transmission shaft to drive the sleeve to rotate relative to the fixed component.

[0006] Preferably, the magnetic field generated by the excitation winding after being energized is opposite in direction to the magnetic field of the permanent magnet; when the voltage output to the excitation winding is less than the first set voltage, the magnetic field of the excitation winding is much smaller than the magnetic field of the permanent magnet, and the total magnetic field of the excitation winding and the permanent magnet has a greater suction force on the magnetic conductive part than the elastic force of the elastic part, and the magnetic conductive part moves toward the fixed component until it is combined with the fixed component, preventing the rotating component and the transmission shaft from rotating, thereby achieving braking; when the voltage output to the excitation winding is greater than the second set voltage and less than the third set voltage, the magnetic field of the excitation winding and the magnetic field of the permanent magnet cancel each other out, and the total magnetic field of the excitation winding and the permanent magnet has a less suction force on the magnetic conductive part than the elastic force of the elastic part, and the magnetic conductive part moves toward the release part until it is separated from the fixed component, allowing the rotating component and the transmission shaft to rotate, thereby achieving brake release.

[0007] Preferably, the first set voltage, the second set voltage and the third set voltage increase in sequence.

[0008] Preferably, the release member is made of a non-magnetic material, the magnetic conductive member is made of a ferromagnetic material, and the elastic member is a leaf spring.

[0009] Based on the same concept, the present invention also provides a control method for the above-mentioned permanent magnet brake, comprising the following steps: The control unit receives the instruction and determines the instruction type; If it is a release instruction, the voltage supply module applies a release voltage U1 to the excitation winding; The current acquisition module collects the real-time current of the excitation winding and calculates the current change slope; When the current change slope is less than or equal to a set first change slope, determining that the permanent magnet brake is released; If it is a braking command, the voltage supply module applies a braking voltage U2 to the excitation winding; The voltage acquisition module collects the real-time induced voltage of the excitation winding and calculates the slope of the induced voltage change; When the induced voltage change slope is less than or equal to a set second change slope, it is determined that the permanent magnet brake completes braking.

[0010] Preferably, the release voltage U1 is greater than the second set voltage and less than the third set voltage, the magnetic field of the excitation winding and the magnetic field of the permanent magnet cancel each other out, the total magnetic field of the excitation winding and the permanent magnet has a suction force on the magnetic conductive part that is less than the elastic force of the elastic part, and the magnetic conductive part moves toward the release part until it is separated from the fixed component, allowing the rotating component and the transmission shaft to rotate, thereby completing the brake release.

[0011] Preferably, after calculating the current change slope, the method further includes: Determine whether the current change slope suddenly changes. If so, it indicates that the magnetic conductive member begins to move toward the release member when the current change slope suddenly changes. After the current change slope suddenly changes, the current change slope is compared with the set first change slope. If the current change slope is less than or equal to the set first change slope, it is determined that the magnetic conductive part is separated from the fixed component and the permanent magnet brake is released.

[0012] Preferably, the braking voltage U2 is less than the first set voltage, the magnetic field of the excitation winding is much smaller than the magnetic field of the permanent magnet, the total magnetic field of the excitation winding and the permanent magnet has a suction force on the magnetic conductive part that is greater than the elastic force of the elastic part, and the magnetic conductive part moves toward the fixed component until it is combined with the fixed component, thereby preventing the rotating component and the transmission shaft from rotating, thereby completing the braking.

[0013] Preferably, after calculating the voltage change slope, the method further includes: Determine whether the slope of the induced voltage change suddenly changes. If so, it indicates that the magnetic conductive component begins to move toward the fixed component when the slope of the induced voltage change suddenly changes. After the induced voltage change slope suddenly changes, the induced voltage change slope is compared with the set second change slope. If the induced voltage change slope is less than or equal to the set second change slope, it is determined that the magnetic conductive part is combined with the fixed component and the permanent magnet brake completes braking.

[0014] Preferably, the method further comprises the following steps: The control unit receives a release instruction; The voltage supply module applies a release voltage U1 to the excitation winding; The current acquisition module collects the real-time current of the excitation winding and calculates the current change slope; When the current change slope is less than or equal to a set first change slope, determining that the permanent magnet brake is released; The voltage supply module applies a braking voltage U2 to the excitation winding; The voltage acquisition module collects the real-time induced voltage of the excitation winding and calculates the voltage change slope; Determining whether a sudden change occurs in the slope of the induced voltage change; if a sudden change occurs and the slope of the induced voltage change is less than or equal to a set third change slope, it indicates that the magnetic conductive member is in a critical combination state with the fixed component; The voltage supply module applies a release voltage U1 and a brake voltage U2 to the excitation winding in turn, so that the magnetic conductive member switches between a release state and a critical engagement state until the control unit receives a brake command.

[0015] Compared with the prior art, the technical solution of the embodiment of the present invention has beneficial effects.

[0016] For example, the permanent magnet brake and control method provided by the present invention realize the control of the magnetic conductive part through the total magnetic field of the permanent magnet and the excitation winding, thereby realizing the braking and release of the permanent magnet brake. The magnetic field directions of the permanent magnet and the excitation winding are opposite, realizing the braking of the excitation winding by power-off and release by power-on; utilizing the influence of the characteristics of the movement of the structural components of the permanent magnet brake on the changing trend of the induced voltage and current of the excitation winding during the release and braking process, the state of the permanent magnet brake is confirmed by the change of the induced voltage and current slope of the excitation winding, avoiding the influence of differences in circuit control parameters caused by factors such as product production performance deviation, environmental impact, and aging during use, thereby improving safety, reliability and response performance.

[0017] For another example, the permanent magnet brake and control method provided by the present invention apply a release voltage U1 and a braking voltage U2 alternately to the excitation winding after power-on release, so that the magnetic conductive part switches between a release state and a critical engagement state to maintain a non-braking state, which is more energy-efficient than constantly applying the release voltage U1 to maintain the release state. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the application of a permanent magnet brake according to an embodiment of the present invention; Figure 2 Schematic diagram of the structure of a permanent magnet brake according to an embodiment of the present invention; Figure 3 Schematic diagram comparing the released state and the braked state of the permanent magnet brake according to an embodiment of the present invention; Figure 4 This is a flow chart of a method for controlling a permanent magnet brake according to an embodiment of the present invention; Figure 5 1 is a current variation characteristic diagram of the excitation winding of the permanent magnet brake under a given release voltage according to an embodiment of the present invention; Figure 6 This is a characteristic diagram of the induced voltage change of the excitation winding of the permanent magnet brake according to an embodiment of the present invention when a given release voltage is converted to a braking voltage; Figure 7 This is a characteristic diagram of the induced voltage and current changes of the excitation winding of the permanent magnet brake according to an embodiment of the present invention when the release voltage and the braking voltage are applied alternately and the brake is not applied.

[0019] Description of reference numerals: 1- Braking unit; 2- Control unit; 3- Rotational motion unit; 4- Transmission unit; 5- Transmission shaft; 110-fixed component; 111-excitation winding; 112-permanent magnet; 113-fixed member; 114-rolling member; 120 - rotating assembly; 121 - elastic member; 122 - release member; 123 - magnetic member; 124 - shaft sleeve; 201 - voltage supply module; 202 - current acquisition module; 203 - voltage acquisition module. DETAILED DESCRIPTION

[0020] To make the objectives, features, and beneficial effects of the present invention more readily apparent, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described below are merely illustrative of the present invention and are not intended to limit the present invention. Furthermore, the same or similar reference numerals may be used in the drawings to refer to the same or similar elements in different embodiments, and descriptions of the same or similar elements in different embodiments, as well as descriptions of prior art elements, features, and effects, may be omitted.

[0021] Reference Figure 1-Figure 3 , an embodiment of the present invention provides a permanent magnet brake.

[0022] Specifically, the permanent magnet brake provided in an embodiment of the present invention includes a braking unit 1 and a control unit 2. The braking unit 1 is arranged on a transmission shaft 5, and the control unit 2 is connected to and controls the braking unit 1; the transmission shaft 5 connects the rotary motion unit 3 and the transmission unit 4, and the rotary motion unit 3 is a rotary drive motor.

[0023] The brake unit 1 includes a rotating component 120 and a fixed component 110 coaxially sleeved on the transmission shaft 5. The rotating component 120 rotates with the transmission shaft 5, and the fixed component 110 is fixedly connected to the vehicle body; the rotating component 120 includes a sleeve 124, a release member 122 and a magnetic member 123. The sleeve 124 is fixedly sleeved on the transmission shaft 5, the release member 122 and the magnetic member 123 are arranged side by side outside the sleeve 124, the release member 122 is fixedly connected to the sleeve 124, and the magnetic member 123 is movably connected to the sleeve 124. The sleeve 124 allows the magnetic member 123 to move axially along the sleeve 124 and prevents the magnetic member 123 from rotating relative to the sleeve 124. An elastic member 121 is provided between the magnetic member 123 and the release member 122; the fixed component 110 is sleeved outside the sleeve 124 and is located at one end close to the magnetic member 123 A rolling member 114 is provided between the fixed component 110 and the sleeve 124, and the rolling member 114 allows the transmission shaft 5 to drive the sleeve 124 to rotate relative to the fixed component 110; the fixed component 110 includes a fixed component 113, an excitation winding 111 and a permanent magnet 112, the excitation winding 111 and the permanent magnet 112 are installed on the fixed component 113, and the excitation winding 111 can be arranged on the permanent magnet 112 or arranged side by side with the permanent magnet 112; the control unit 2 is connected to the excitation winding 111, and the control unit 2 includes a voltage power supply module 201, a current acquisition module 202 and a voltage acquisition module 203; the voltage power supply module 201 outputs voltage to the excitation winding 111, the current acquisition module 202 collects the current of the excitation winding 111, and the voltage acquisition module 203 collects the induced voltage of the excitation winding 111.

[0024] In some embodiments, the magnetic field generated by the excitation winding 111 after being energized is opposite to the direction of the magnetic field of the permanent magnet 112; when the voltage output to the excitation winding 111 is less than the first set voltage, the magnetic field of the excitation winding 111 is much smaller than the magnetic field of the permanent magnet 112, and the total magnetic field of the excitation winding 111 and the permanent magnet 112 has a suction force on the magnetic conductive member 123 that is greater than the elastic force of the elastic member 121, and the magnetic conductive member 123 moves toward the fixed component 110 until it is combined with the fixed component 110, preventing the rotating component 120 and the transmission shaft 5 from rotating, thereby achieving braking; when the voltage output to the excitation winding 111 is greater than the second set voltage and less than the third set voltage, the magnetic field of the excitation winding 111 and the magnetic field of the permanent magnet 112 cancel each other out. The magnetic conductive part 123 moves toward the release part 122 until it is separated from the fixed component 110, allowing the rotating component 120 and the transmission shaft 5 to rotate, thereby realizing brake release; when the voltage output to the excitation winding 111 is greater than the fourth set voltage, the magnetic field of the excitation winding 111 is much greater than the magnetic field of the permanent magnet 112, and the suction force of the total magnetic field of the excitation winding 111 and the permanent magnet 112 on the magnetic conductive part 123 is greater than the elastic force of the elastic part 121, and the magnetic conductive part 123 moves toward the fixed component 110 until it is combined with the fixed component 110, thereby preventing the rotating component 120 and the transmission shaft 5 from rotating, thereby realizing braking.

[0025] In some embodiments, the first set voltage, the second set voltage, the third set voltage, and the fourth set voltage increase sequentially.

[0026] In some embodiments, the release member 122 is made of non-magnetic material, the magnetic conductive member 123 is made of ferromagnetic material, the elastic member 121 is a leaf spring, and the rolling member 114 is a ball or roller.

[0027] See also Figure 4 The control method of the permanent magnet brake provided by the embodiment of the present invention includes the following steps: S1: Control unit 2 receives the instruction and determines the instruction type; S2: If it is a release instruction, the voltage supply module 201 applies a release voltage U1 to the excitation winding 111; The release voltage U1 is greater than the second set voltage and less than the third set voltage. The magnetic field of the excitation winding 111 and the magnetic field of the permanent magnet 112 cancel each other out. The total magnetic field of the excitation winding 111 and the permanent magnet 112 exerts a suction force on the magnetic conductive member 123 that is less than the elastic force of the elastic member 121. The magnetic conductive member 123 moves toward the release member 122 until it is separated from the fixed assembly 110, allowing the rotating assembly 120 and the transmission shaft 5 to rotate, thereby completing the brake release. The current variation characteristics of the excitation winding 111 under the release voltage U1 are as follows: Figure 5As shown, before time t1, the magnetic component 123 and the fixed component 110 are still in a combined state, the equivalent inductance is small, and the slope of the current rise is the highest; in the time t1-t2 stage, the magnetic component 123 is in motion, the equivalent inductance increases, and the current rise slope decreases significantly; at time t2, the magnetic component 123 stops moving, the equivalent inductance increases to the maximum state, and the current rise slope further decreases significantly; at time t3, the current slope is already very small, reaching a stable stage.

[0028] The current acquisition module 202 collects the real-time current of the excitation winding 111 and calculates the current change slope; Determine whether the current change slope has a sudden change. If a sudden change occurs (at time t1), it means that the magnetic conductive member 123 begins to move toward the release member 122 when the current change slope has a sudden change. After the current change slope suddenly changes, the current change slope is compared with the set first change slope. If the current change slope is less than or equal to the set first change slope (at time t2), it is determined that the magnetic permeable member 123 is separated from the fixing assembly 110 and the permanent magnet brake is released. When the current change slope is less than or equal to the set first change slope, it is determined that the permanent magnet brake is released. The existing technology usually determines that the brake is released when the current is stable, that is, at time t3, which is obviously delayed in time.

[0029] S3: If it is a braking instruction, the voltage supply module 201 applies a braking voltage U2 to the excitation winding 111; The braking voltage U2 is lower than the first set voltage, the magnetic field of the excitation winding 111 is much lower than the magnetic field of the permanent magnet 112, and the total magnetic field of the excitation winding 111 and the permanent magnet 112 exerts a suction force on the magnetic conductive part 123 that is greater than the elastic force of the elastic part 121. The magnetic conductive part 123 moves toward the fixed component 110 until it is combined with the fixed component 110, preventing the rotating component 120 and the transmission shaft 5 from rotating, thereby completing the braking.

[0030] The induced voltage variation characteristics of the excitation winding 111 when the release voltage U1 is converted to the braking voltage U2 are as follows: Figure 6 As shown, before time t4, the magnetic member 123 and the fixed component 110 are still in a combined state, the equivalent inductance is maximum, the back electromotive force of the excitation winding 111 decreases and the slope of change is the highest; during the time t4-t5 stage, the magnetic member 123 is in a moving process, the equivalent inductance decreases, the back electromotive force of the excitation winding 111 decreases and the slope of change decreases significantly; at time t5, the magnetic member 123 stops moving, the equivalent inductance decreases to a minimum state, the back electromotive force of the excitation winding 111 decreases and the slope of change further decreases significantly; at time t6, the slope of the current is already very small, and it reaches a stable stage.

[0031] The voltage acquisition module 203 collects the real-time induced voltage of the excitation winding 111 and calculates the slope of the induced voltage change; Determine whether the slope of the induced voltage change suddenly changes. If so (at time t4), it means that the magnetic conductive member 123 begins to move toward the fixed component 110 when the slope of the induced voltage change suddenly changes. After the induced voltage change slope suddenly changes, the induced voltage change slope is compared with the set second change slope. If the induced voltage change slope is less than or equal to the set second change slope (at time t5), it is determined that the magnetic permeable member 123 is combined with the fixed component 110, and the permanent magnet brake completes braking. When the induced voltage change slope is less than or equal to the set second change slope, it is determined that the permanent magnet brake has completed braking; the existing technology usually determines that the brake has completed braking when the voltage is stable, that is, at time t6, which is significantly delayed in time.

[0032] More precise structural state control saves unnecessary waiting time and reduces energy consumption in the waiting link of the control system; it saves unnecessary circuit signal steady-state waiting time and achieves faster release and combination; it can identify the position status of the magnetic component 123, and the control is more accurate and reliable, and the braking process is safer; it does not require excessive product quality consistency and product process performance consistency, reduces the requirements for materials and design, and has obvious cost advantages.

[0033] In some embodiments, when the control unit 2 receives a release instruction and needs to maintain a certain release time, it applies the release voltage U1 and the braking voltage U2 to the excitation winding 111 in the release state and keeps the excitation winding 111 from braking. The induced voltage and current change characteristics of the excitation winding 111 are as follows: Figure 7 As shown, the specific control method is as follows: The voltage supply module 201 applies a release voltage U1 to the excitation winding 111; The current acquisition module 202 collects the real-time current of the excitation winding 111 and calculates the current change slope; When the current change slope is less than or equal to a set first change slope, determining that the permanent magnet brake is released; The voltage supply module 201 applies a braking voltage U2 to the excitation winding 111; The voltage acquisition module 203 collects the real-time induced voltage of the excitation winding 111 and calculates the slope of the induced voltage change; Determine whether the induced voltage change slope has a sudden change (at time t7). If a sudden change occurs and the induced voltage change slope is less than or equal to the set third change slope (at time t8), and the third change slope is slightly greater than the second change slope, it indicates that the magnetic permeable member 123 is in a critical bonding state with the fixing assembly 110; The voltage supply module 201 applies the release voltage U1 to the excitation winding 111 again; The current acquisition module 202 collects the real-time current of the excitation winding 111 and calculates the current change slope; When the current change slope is less than or equal to the set first change slope (at time t9), it is determined that the permanent magnet brake is released; The voltage supply module 201 alternately applies a release voltage U1 and a brake voltage U2 to the excitation winding 111, causing the magnetic member 123 to switch between the released state and the critically engaged state until the control unit 2 receives a braking command. Maintaining no braking and allowing the magnetic member 123 to switch between the released state and the critically engaged state is more energy-efficient than continuously applying the release voltage U1 to maintain the released state.

[0034] In summary, the permanent magnet brake and control method thereof provided by the present invention realize control of the magnetic conductive member 123 through the total magnetic field of the permanent magnet 112 and the excitation winding 111, thereby realizing braking and releasing of the permanent magnet brake. The magnetic fields of the permanent magnet 112 and the excitation winding 111 are in opposite directions, realizing power-off braking and power-on release of the excitation winding 111; utilizing the influence of the characteristics of the movement of the structural components of the permanent magnet brake on the changing trends of the voltage and current of the excitation winding 111 during the release and braking process, the state of the permanent magnet brake is confirmed by the change of the voltage and current slope of the excitation winding 111, avoiding the influence of differences in circuit control parameters caused by factors such as product production performance deviation, environmental influence, and aging during use, thereby improving safety, reliability and response performance.

[0035] Furthermore, the permanent magnet brake and control method thereof provided by the present invention alternately applies a release voltage U1 and a braking voltage U2 to the excitation winding 111 after power-on release, so that the magnetic conductive part 123 switches between a release state and a critical engagement state, which is more energy-efficient than constantly applying the release voltage U1 to maintain the release state.

[0036] Although specific embodiments have been described above, these embodiments are not intended to limit the scope of the present disclosure, even when only a single embodiment is described with respect to specific features. The feature examples provided in the present disclosure are intended to be illustrative, not limiting, unless otherwise stated. In specific implementations, the technical features of one or more dependent claims may be combined with the technical features of the independent claim, based on actual needs and where technically feasible, and may be derived from the technical features of the corresponding independent claim in any appropriate manner rather than solely through the specific combinations listed in the claims.

[0037] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A permanent magnet brake, characterized in that: include: A brake unit, the brake unit comprising a rotating assembly and a fixed assembly coaxially sleeved on the transmission shaft; the rotating assembly rotates with the transmission shaft; The fixed component is fixedly connected to the vehicle body and is located on one side of the rotating component; and A control unit, the control unit includes a voltage supply module, a current acquisition module and a voltage acquisition module; the voltage supply module outputs voltage to the fixed component, the current acquisition module collects the current of the fixed component, and the voltage acquisition module collects the induced voltage of the fixed component.

2. The permanent magnet brake according to claim 1, characterized in that: The rotating assembly comprises a sleeve, a release member and a magnetic conductive member, wherein the sleeve is fixedly sleeved on the transmission shaft, the release member and the magnetic conductive member are arranged side by side outside the sleeve, the release member is fixedly connected to the sleeve, the magnetic conductive member is movably connected to the sleeve, the sleeve allows the magnetic conductive member to move axially along the sleeve and prevents the magnetic conductive member from rotating relative to the sleeve, and an elastic member is arranged between the magnetic conductive member and the release member; The fixed component includes a fixed part, an excitation winding and a permanent magnet, and the excitation winding and the permanent magnet are installed on the fixed part; a rolling element is arranged between the fixed component and the sleeve, and the rolling element allows the transmission shaft to drive the sleeve to rotate relative to the fixed component; the fixed component is located at one end close to the magnetic conductive part.

3. The permanent magnet brake according to claim 2, characterized in that: The voltage supply module outputs voltage to the excitation winding, the current acquisition module acquires the current of the excitation winding, and the voltage acquisition module acquires the induced voltage of the excitation winding; When the voltage output to the excitation winding is less than the first set voltage, the magnetic field of the excitation winding is smaller than the magnetic field of the permanent magnet, the attraction of the total magnetic field of the excitation winding and the permanent magnet on the magnetic conductive member is greater than the elastic force of the elastic member, the magnetic conductive member moves toward the fixed component until it is combined with the fixed component, thereby preventing the rotating component and the transmission shaft from rotating, and the permanent magnet brake realizes braking; When the voltage output to the excitation winding is greater than the second set voltage and less than the third set voltage, the magnetic field of the excitation winding and the magnetic field of the permanent magnet cancel each other out, and the attraction of the total magnetic field of the excitation winding and the permanent magnet on the magnetic conductive member is less than the elastic force of the elastic member, and the magnetic conductive member moves toward the release member until it is separated from the fixed component, allowing the rotating component and the transmission shaft to rotate, and the permanent magnet brake realizes brake release; The first setting voltage, the second setting voltage and the third setting voltage increase in sequence.

4. The permanent magnet brake according to claim 2, characterized in that: The release member is made of non-magnetic material, the magnetic conductive member is made of ferromagnetic material, and the elastic member is a plate spring.

5. A control method for a permanent magnet brake according to any one of claims 1 to 4, characterized in that: The steps include: The control unit receives the instruction and determines the instruction type; If it is a release command, the voltage supply module applies a release voltage U1 to the excitation winding; The current acquisition module collects the real-time current of the excitation winding and calculates the current change slope; When the current change slope is less than or equal to a set first change slope, determining that the permanent magnet brake has completed release; If it is a braking command, the voltage supply module applies a braking voltage U2 to the excitation winding; The voltage acquisition module collects the real-time induced voltage of the excitation winding and calculates the slope of the induced voltage change; When the induced voltage change slope is less than or equal to a set second change slope, it is determined that the permanent magnet brake completes braking.

6. The control method of the permanent magnet brake according to claim 5, characterized in that: The release voltage U1 is greater than the second set voltage and less than the third set voltage, the magnetic field of the excitation winding and the magnetic field of the permanent magnet cancel each other out, the total magnetic field of the excitation winding and the permanent magnet has a suction force on the magnetic conductive part that is less than the elastic force of the elastic part, and the magnetic conductive part moves toward the release part until it is separated from the fixed component, allowing the rotating component and the transmission shaft to rotate, thereby completing the brake release.

7. The control method of the permanent magnet brake according to claim 6, characterized in that: After calculating the current change slope, it also includes: Determine whether the current change slope suddenly changes. If so, it means that the magnetic conductive member starts to move toward the release member when the current change slope suddenly changes. After the current change slope suddenly changes, the current change slope is compared with the set first change slope. If the current change slope is less than or equal to the set first change slope, it is determined that the magnetic conductive part is separated from the fixed component and the permanent magnet brake is released.

8. The control method of the permanent magnet brake according to claim 5, characterized in that: The braking voltage U2 is lower than the first set voltage, the magnetic field of the excitation winding is much lower than the magnetic field of the permanent magnet, the total magnetic field of the excitation winding and the permanent magnet has a suction force on the magnetic conductive part that is greater than the elastic force of the elastic part, and the magnetic conductive part moves toward the fixed component until it is combined with the fixed component, thereby preventing the rotating component and the transmission shaft from rotating and completing the braking.

9. The control method of the permanent magnet brake according to claim 8, characterized in that: After calculating the slope of the induced voltage change, it also includes: Determine whether the slope of the induced voltage change suddenly changes. If so, it means that the magnetic conductive component starts to move toward the fixed component when the slope of the induced voltage change suddenly changes. After the induced voltage change slope changes suddenly, the induced voltage change slope is compared with the set second change slope. If the induced voltage change slope is less than or equal to the set second change slope, it is determined that the magnetic conductive part is combined with the fixed component and the permanent magnet brake completes braking.

10. The control method of the permanent magnet brake according to claim 5, characterized in that: The following steps are also included: The control unit receives a release instruction; The voltage supply module applies a release voltage U1 to the excitation winding; The current acquisition module collects the real-time current of the excitation winding and calculates the current change slope; When the current change slope is less than or equal to a set first change slope, determining that the permanent magnet brake has completed release; The voltage supply module applies a braking voltage U2 to the field winding; The voltage acquisition module collects the real-time induced voltage of the excitation winding and calculates the voltage change slope; Determine whether the induced voltage change slope has a sudden change. If a sudden change occurs and the induced voltage change slope is less than or equal to the set third change slope, it indicates that the magnetic conductive component is in a critical combination state with the fixed component; The voltage supply module applies a release voltage U1 and a brake voltage U2 to the excitation winding in turn, so that the magnetic conductive member switches between a release state and a critically coupled state until the control unit receives a brake command.

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