A driver based on shape memory alloy material and a control method

Abstract

The application discloses a kind of driver and control method based on shape memory alloy drive spring.The driver includes shell, rotatable output shaft relative shell, rotor and drive spring made of shape memory alloy material and connected with rotor and shell at both ends respectively, drive spring is deformed when energized heating, produce the torque that acts on rotor, drive rotor relative shell rotation and drive output shaft to realize rotary output.By the above structure, in the case of not relying on motor and speed reducer, the deformation of shape memory alloy is directly converted into available rotary driving force, the overall structure is simple, small in size, light in weight, and the body basically does not produce electromagnetic interference, suitable for the rotary driving occasion with higher space and electromagnetic compatibility requirement.On this basis, the application further realizes the angle closed-loop control of the driver by setting angular displacement sensor and controller.

Description

Technical Field

[0001] This disclosure relates to the field of rotary actuator technology, and specifically to an actuator and control method based on shape memory alloy material. Background Technology

[0002] Currently, the most commonly used rotary drive devices in engineering applications are those consisting of a motor and a reducer. While this type of solution is technically mature, it has the following problems: 1. Large size and weight: The motor and reducer occupy a large space and have a large overall weight, which is not conducive to the miniaturization and lightweight design of the system, especially in applications such as aircraft and robot joints where weight and space are very sensitive.

[0003] 2. Electromagnetic interference problem: Motors rely on electromagnetic force to work, and generate a strong electromagnetic field during operation, which can easily cause electromagnetic interference to sensitive electronic equipment in the surrounding area, and is not conducive to the electromagnetic compatibility design of the system.

[0004] 3. Complex structure and limited reliability: The transmission chain of the motor and reducer is relatively long, involving multiple links such as gear meshing and bearing support. The structure is complex and has many parts, which limits its reliability in harsh environments such as high temperature and high vibration.

[0005] Shape memory alloys (SMAs) possess reversible phase transformation properties, undergoing a phase transformation between martensite and austenite phases during heating and cooling, resulting in significant shape recovery deformation. In existing technologies, SMAs have found some applications in linear actuators, clamping mechanisms, and other fields, but these are mostly limited to linear drive or simple clamping scenarios.

[0006] For applications requiring rotary output, there is currently a lack of rotary actuator solutions that fully utilize the properties of shape memory alloys, possess a simple and compact structure, offer controllable output torque, and facilitate closed-loop control with a control system. Therefore, it is necessary to provide a new shape memory alloy-driven rotary actuator and control method to overcome these shortcomings.

[0007] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0008] The purpose of this disclosure is to provide an actuator and control method based on shape memory alloy materials, thereby overcoming, at least to some extent, one or more problems caused by the limitations and defects of related technologies.

[0009] According to one aspect of this disclosure, a drive based on a shape memory alloy material is provided, comprising: a housing; an output shaft rotatably disposed relative to the housing; a rotor sleeved on the output shaft and fixedly connected to the output shaft to rotate together with the output shaft; and a drive spring made of the shape memory alloy material, with its two ends respectively connected to the rotor and the housing, wherein the drive spring deforms when electrically heated to generate a torque acting on the rotor to drive the rotor to rotate relative to the housing.

[0010] Furthermore, the drive spring is arranged circumferentially between the rotor and the housing.

[0011] Furthermore, the drive spring is a helical or torsional shape memory alloy spring.

[0012] Furthermore, the drive spring is electrically connected to the power output terminal of an external controller via a wire to receive the current used for heating.

[0013] Furthermore, it also includes: an end cap, disposed at one end of the housing and fixedly connected to the housing; at least one pair of bearings, arranged on the end cap, the output shaft being rotatably mounted on the end cap via the bearings and extending out of the housing through the end cap.

[0014] Furthermore, it also includes: a rotor cover plate, fixedly installed on one side of the rotor; a torsion spring, sleeved on the output shaft, having a first torsion arm and a second torsion arm, the first torsion arm being connected to the rotor cover plate, and the second torsion arm being fixedly connected to the housing, wherein, when the drive spring stops being energized and cools down to reset, the torsion spring applies a reverse torque to the rotor to drive the rotor and the output shaft back to the initial angular position.

[0015] Furthermore, it also includes: a spacer, installed inside the housing, for axially pressing the second torsion arm of the torsion spring connected to the housing.

[0016] A second aspect of this disclosure provides a drive system, comprising: the drive described above; a coupling for connecting the output shaft of the drive to an external load; an angular displacement sensor coaxially connected to the output shaft and / or the coupling for real-time acquisition of the output angle of the drive and outputting an analog voltage signal; and a controller electrically connected to the angular displacement sensor and the drive spring for heating control of the drive spring and achieving closed-loop control of the drive.

[0017] Furthermore, the controller includes: an angular displacement sensor acquisition circuit for protecting and filtering the analog voltage signal output by the angular displacement sensor and outputting it to the analog-to-digital conversion module; a minimum control system for acquiring the angle data converted by the analog-to-digital conversion module, executing the control algorithm, and outputting a control signal; a power output heating drive circuit for generating a PWM signal based on the control signal output by the minimum control system and driving the power switching device to adjust the voltage and current applied to the drive spring; and a communication circuit for data communication with a host computer.

[0018] Furthermore, the communication circuit adopts an RS-422 interface. The minimum control system receives the target angle setting value sent by the host computer through the RS-422 interface and sends the driver status information back to the host computer.

[0019] Furthermore, the minimum control system is configured to output a PWM signal at a frequency of approximately 10 kHz and to sample the angle signal and update the control quantity at a period of approximately 1 ms.

[0020] This disclosure provides a third aspect of a actuator control method based on a shape memory alloy drive spring, applied to the aforementioned actuator system, comprising the following steps: S1, angle acquisition: an angular displacement sensor detects the mechanical angle of the output shaft in real time, outputs an analog voltage signal, which is processed by the angular displacement sensor acquisition circuit and input to the analog-to-digital converter module of the controller to obtain the current angle θ_cur; S2, target reception: the controller receives the target angle setpoint θ_set sent by the host computer through the communication circuit; S3, cascade PID calculation: the controller executes a cascade PID control algorithm, the outer loop calculates the target heating amount or target current of the drive spring with the angle error (θ_set - θ_cur) as input, and the inner loop calculates the target heating amount or target current of the drive spring based on the temperature change rate of the drive spring. S4, PWM modulation and heating drive: The controller generates a PWM signal based on the cascaded PID calculation results, and adjusts the voltage and current applied to the drive spring through the power output heating drive circuit, so that the drive spring is heated and deformed, driving the rotor and the output shaft to rotate; S5, closed-loop correction: The controller periodically collects the output of the angular displacement sensor, updates the current angle θ_cur, and corrects the duty cycle of the PWM signal until the angle of the output shaft reaches the target angle set value θ_set; S6, reset control: When the driver needs to be reset, the controller cuts off the current applied to the drive spring, so that the drive spring is cooled and reset under the torque of the torsion spring and drives the rotor and the output shaft back to the initial angle position.

[0021] Furthermore, in step S4, the controller matches the heating time t of the drive spring with the heating current I according to the relationship t=mcΔT / (I²R) during the heating process of the shape memory alloy, where m is the mass of the drive spring, c is the specific heat capacity of the shape memory alloy, ΔT is the temperature difference required for the transition from martensite to austenite, and R is the resistance of the drive spring, so as to adjust the rotation speed of the driver.

[0022] This invention directly converts the deformation of shape memory alloys into usable rotary driving force without relying on motors and reducers. The overall structure is simple, small in size, and lightweight, and the body generates virtually no electromagnetic interference, making it suitable for rotary drive applications with high requirements for space and electromagnetic compatibility. Furthermore, this invention achieves closed-loop angle control of the actuator by incorporating an angular displacement sensor and controller.

[0023] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0024] The above and other features and advantages of this disclosure will become more apparent from the detailed description of exemplary embodiments thereof with reference to the accompanying drawings.

[0025] Figure 1 A schematic diagram of the structure of a driver system according to an exemplary embodiment of the present disclosure is shown; Figure 2 A schematic diagram of the external structure of a driver according to an exemplary embodiment of the present disclosure is shown; Figure 3 A schematic axial cross-sectional view of a drive according to an exemplary embodiment of the present disclosure is shown; Figure 4 A schematic diagram of the internal structure of the actuator after removing the end cap, according to an exemplary embodiment of the present disclosure, is shown. Figure 5 A block diagram of the internal functional modules of the controller according to an exemplary embodiment of the present disclosure is shown; Figure 6 A schematic diagram of the assembly of the rotor and drive spring in a driver according to an exemplary embodiment of the present disclosure is shown; Figure 7 A schematic diagram of the assembly of a rotor and a rotor cover plate according to an exemplary embodiment of the present disclosure is shown; Figure 8 A schematic diagram of the mounting structure of a torsion spring and spacer in a driver according to an exemplary embodiment of the present disclosure is shown. Figure 9 A schematic diagram is shown of a driver according to an exemplary embodiment of the present disclosure driving a spring in a pre-compressed state in an initial state; Figure 10 A schematic diagram of a rotor rotating during the heating and elongation of a drive spring, according to an exemplary embodiment of the present disclosure, is shown. Figure 11 A schematic diagram of a driver according to an exemplary embodiment of the present disclosure is shown, in which the drive spring is cooled and reset under the action of a torsion spring; Figure 12 A schematic block diagram of the cascaded PID control and PWM modulation process in a control method according to an exemplary embodiment of the present disclosure is shown.

[0026] Figure label: 01—Driver; 02—Coupling; 03—Angular displacement sensor; 04—Controller; 0101—Output shaft; 0102—End cover; 0103—Outer shell; 0104—Bearing; 0105—Spacer; 0106—Torsion spring; 0107—Rotor cover plate; 0108—Rotor; 0109—Drive spring (shape memory alloy drive spring). Detailed Implementation

[0027] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted.

[0028] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced without one or more of the specific details described, or other methods, components, materials, apparatuses, steps, etc., can be employed. In other instances, well-known structures, methods, systems, implementations, materials, or operations are not shown or described in detail to avoid obscuring various aspects of this disclosure.

[0029] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, or in one or more software-hardened modules, or in different network and / or processor devices and / or microcontroller devices.

[0030] In this example embodiment, as Figure 2 and Figure 3As shown, the driver provided in this embodiment includes at least a housing 0103, an output shaft 0101, a rotor 0108, and a drive spring 0109.

[0031] The output shaft 0101 is rotatably mounted relative to the housing 0103. The rotor 0108 is sleeved on the output shaft 0101 and fixedly connected to the output shaft 0101 so as to rotate together with the output shaft 0101.

[0032] The drive spring 0109 is made of shape memory alloy material, and its two ends are connected to the rotor 0108 and the housing 0103 respectively.

[0033] When a heating current is applied to the drive spring 0109 during operation, the temperature of the drive spring 0109 increases and it undergoes shape recovery deformation, generating relative torsional displacement and torque at its two ends. This torque acts on the rotor 0108, thereby driving the rotor 0108 to rotate relative to the housing 0103, and driving the output shaft 0101 to rotate, thus realizing rotational drive output.

[0034] In this embodiment, the drive spring 0109 is made of a shape memory alloy material that can undergo a reversible phase transformation between the martensitic and austenitic phases. The specific composition, phase transformation temperature and the geometry of the spring can be designed according to the requirements of the target output torque and angle.

[0035] In a preferred embodiment, such as Figures 2 to 4 As shown, an end cap 0102 is installed on one end of the outer casing 0103, and the end cap 0102 is fixedly connected to the outer casing 0103 by screws or other fasteners.

[0036] At least one pair of bearings 0104 are provided on the end cover 0102. The output shaft 0101 is rotatably mounted on the end cover 0102 via the bearings 0104 and extends out of the housing 0103 through the end cover 0102 for connection with an external load or coupling 02. The above structural arrangement can improve the rotational accuracy and load-bearing capacity of the output shaft 0101.

[0037] In this embodiment, a drive spring 0109 is arranged circumferentially between the rotor 0108 and the housing 0103, and is preferably a helical or torsional shape memory alloy spring. The drive spring 0109 is electrically connected to the power output terminal of the controller 04 via a wire to receive controlled heating current.

[0038] like Figures 6 to 8 As shown, in another preferred embodiment, the driver further includes a rotor cover 0107 and a torsion spring 0106.

[0039] The rotor cover plate 0107 is fixedly installed on one side of the rotor 0108 and can be reliably connected to the rotor 0108 by means of screws or pins.

[0040] The torsion spring 0106 is sleeved on the output shaft 0101 and has a first torsion arm and a second torsion arm. The first torsion arm is connected to the rotor cover plate 0107, and the second torsion arm is fixedly connected to the housing 0103. For example, holes or slots for inserting the torsion spring arms can be provided on the rotor cover plate 0107 and the housing 0103, respectively. The torsion spring is fixedly connected to the relevant parts after being pre-tightened by torsion.

[0041] Preferably, the driver further includes a spacer 0105, which is installed inside the housing 0103 and is used to press the second torsion arm of the torsion spring 0106 connected to the housing 0103 in the axial direction to ensure the positioning and stability of the torsion spring 0106 during the operation of the driver.

[0042] In this preferred embodiment, the operation of the driver can be described as follows: In the initial state, such as Figure 9 As shown, the torsion spring 0106 is pre-applied with a certain torque, so that the drive spring 0109 is in a pre-compressed state, and the rotor 0108 is located at the initial angle position relative to the outer shell 0103. When the controller 04 supplies electricity to heat the drive spring 0109, the drive spring 0109 heats up and undergoes shape recovery deformation. The effective length of the drive spring 0109 extends along the circumferential direction, thereby driving the rotor 0108 to rotate relative to the outer casing 0103. Figure 10 As shown, the output shaft 0101 rotates together with the rotor 0108 to drive the external load; When a reset is required or the controller 04 stops heating the drive spring 0109, the drive spring 0109 cools down during heat dissipation. When its temperature drops below the phase transition temperature, it returns to its original shape. Under the reverse torque applied by the torsion spring 0106, the rotor 0108 and the output shaft 0101 are driven back to their initial angular positions. Figure 11 As shown, this enables automatic rotational reset of the driver.

[0043] By rationally designing the stiffness and preload angle of the torsion spring 0106, and the dimensions and material properties of the drive spring 0109, the required output torque and maximum rotation angle can be obtained.

[0044] like Figure 1 and Figure 5 As shown, in one embodiment, the drive system of the present invention includes a drive 01 of any of the foregoing embodiments, as well as a coupling 02, an angular displacement sensor 03, and a controller 04.

[0045] Coupling 02 is used to connect the output shaft 0101 of the driver 01 to an external load. Angular displacement sensor 03 is coaxially connected to the output shaft 0101 and / or coupling 02, used to acquire the output angle information of the driver in real time, and output an analog voltage signal proportional to the angle.

[0046] The controller 04 is electrically connected to the angular displacement sensor 03 and the drive spring 0109, and is used to control the heating of the drive spring 0109 based on the output of the angular displacement sensor 03, thereby performing closed-loop control of the driver 01.

[0047] like Figure 5 As shown, controller 04 specifically includes: The angular displacement sensor acquisition circuit is used to perform overvoltage protection, filtering, and other processing on the analog voltage signal output by the angular displacement sensor 03, and then output it to the analog-to-digital conversion module. The minimum control system is used to collect angle data after analog-to-digital conversion, execute a cascaded PID control algorithm, and output a control signal for adjusting the heating current of the drive spring 0109. The power output heating drive circuit is used to generate a PWM waveform according to the control signal of the control minimum system and drive power switching devices such as power MOSFETs to regulate the voltage and current applied to the drive spring 0109. Communication circuits, such as those using an RS-422 interface, are used for data communication with a host computer.

[0048] In a preferred embodiment, the minimum control system receives the target angle setpoint θ_set sent by the host computer via an RS-422 interface, and sends back parameters such as the current angle θ_cur, drive current, and operating status to the host computer. The minimum control system is preferably configured to output a PWM signal at a frequency of approximately 10kHz and sample the angle signal and update the control quantity at a period of approximately 1ms to improve system response speed and control accuracy.

[0049] In one embodiment, such as Figure 12 As shown, the control method of the present invention is applied to the above-mentioned drive system, and includes the following steps: S100 Angle Acquisition: The angular displacement sensor 03 detects the mechanical angle of the output shaft 0101 in real time and outputs an analog voltage signal proportional to the angle. After being processed by the angular displacement sensor acquisition circuit, the signal is input to the analog-to-digital conversion module of the controller 04 to obtain the current angle θ_cur.

[0050] S110 Target Reception: Controller 04 receives the target angle setting value θ_set sent by the host computer through a communication circuit (e.g., RS-422 interface).

[0051] S120 Cascade PID Operation: Controller 04 executes the cascade PID control algorithm. The outer loop takes the angle error e_θ = θ_set - θ_cur as input and calculates the target heating amount or target current required for the drive spring 0109 based on the set PID parameters; the inner loop dynamically corrects the target heating amount or target current based on the temperature change rate of the drive spring 0109 or temperature-related estimates to suppress overshoot and improve response speed and control stability.

[0052] S130PWM Modulation and Heating Drive: The controller 04 generates a PWM signal with a corresponding duty cycle based on the cascade PID calculation results. The voltage and current applied to the drive spring 0109 are adjusted through the power output heating drive circuit, so that the drive spring 0109 is heated and deformed, driving the rotor 0108 and the output shaft 0101 to rotate, so that the angle of the output shaft 0101 approaches the target angle θ_set.

[0053] S140 Closed-loop correction: Controller 04 continuously acquires the output of angular displacement sensor 03 at a period of approximately 1ms and updates the current angle θ_cur, correcting the duty cycle of the PWM signal in real time until the angle of output shaft 0101 reaches the target angle set value θ_set, thus completing the angle closed-loop control.

[0054] S150 Reset Control: When the driver needs to be reset, the controller 04 cuts off the current applied to the drive spring 0109, allowing the drive spring 0109 to cool down and return to its initial shape. Under the action of the reverse torque applied by the torsion spring 0106, the rotor 0108 and the output shaft 0101 return to the initial angle position, realizing the automatic rotation reset of the driver.

[0055] During the above control process, the heating process of the drive spring 0109 also satisfies the following relationship: ; Where t is the heating time, m is the mass of the drive spring 0109, c is the specific heat capacity of the shape memory alloy material, ΔT is the temperature difference required for the transition from martensitic to austenitic state, and R is the resistance of the drive spring 0109. From this relationship, it can be seen that, with fixed structural parameters, the heating time t is inversely proportional to the heating current I. Therefore, by adjusting the PWM duty cycle to change the magnitude of the heating current I, the deformation time of the drive spring 0109 can be controlled, thereby adjusting the rotational speed of the actuator.

[0056] In summary, compared with the prior art, the present invention has at least the following beneficial effects: 1. Compact structure, small size and light weight: This invention utilizes a drive spring made of shape memory alloy material to directly generate torque, eliminating the volume and weight of traditional motors with reducers. The overall structure of the drive is simple, small in size and light in weight, making it suitable for space- and weight-sensitive applications such as aircraft and robot joints.

[0057] 2. Minimal electromagnetic interference: The actuator body relies on the thermally induced phase deformation of shape memory alloy to output torque, without relying on electromagnetic force to generate driving force. During operation, it generates almost no electromagnetic field, which is beneficial to improving the electromagnetic compatibility of the system.

[0058] 3. Rotary output and automatic reset: The two ends of the drive spring are connected to the rotor and the outer shell respectively. When heated, the torque generated drives the rotor to rotate relative to the outer shell, realizing rotary output. In the preferred embodiment, in conjunction with the reset mechanism composed of torsion spring and spacer, the rotor and output shaft can be automatically reset to the initial angle position when the drive spring cools down, which facilitates periodic reciprocating motion.

[0059] 4. Easy to achieve closed-loop precise control: By setting an angular displacement sensor on the output shaft and cooperating with the controller's cascade PID control algorithm and PWM current modulation, the heating current of the drive spring can be finely adjusted, which can realize closed-loop control of the output shaft angle and speed, with high control accuracy and fast response speed.

[0060] 5. Flexible engineering applications: The arrangement of the drive springs, the support structure of the housing and bearings, the specific installation method of the torsion springs and spacers, the communication interface and control parameters of the controller can all be adjusted and optimized according to different application scenarios, which has good versatility and expandability.

[0061] Furthermore, the above figures are merely illustrative of the processes included in the method according to exemplary embodiments of the present invention, and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0062] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the claims.

[0063] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. An actuator based on shape memory alloy material, characterized in that, include: The outer casing (0103) includes an output shaft (0101) rotatably disposed relative to the outer casing (0103); a rotor (0108) sleeved on the output shaft (0101) and fixedly connected to the output shaft (0101) to rotate together with the output shaft (0101); and a drive spring (0109) made of shape memory alloy material, with its two ends connected to the rotor (0108) and the outer casing (0103) respectively. The drive spring (0109) deforms when heated by electricity, generating a torque acting on the rotor (0108) to drive the rotor (0108) to rotate relative to the outer casing (0103).

2. The driver as claimed in claim 1, characterized in that, The drive spring (0109) is arranged circumferentially between the rotor (0108) and the outer casing (0103).

3. The driver as claimed in claim 1, characterized in that, The drive spring (0109) is a helical or torsional shape memory alloy spring.

4. The driver as claimed in claim 1, characterized in that, The drive spring (0109) is electrically connected to the power output terminal of an external controller via a wire to receive current for heating.

5. The driver as claimed in claim 1, characterized in that, Also includes: An end cap (0102) is disposed at one end of the housing (0103) and fixedly connected to the housing (0103); at least one pair of bearings (0104) are arranged on the end cap (0102), and the output shaft (0101) is rotatably mounted on the end cap (0102) through the bearings (0104) and extends out of the housing (0103) through the end cap (0102).

6. The driver as claimed in claim 1, characterized in that, Also includes: A rotor cover plate (0107) is fixedly installed on one side of the rotor (0108); a torsion spring (0106) is sleeved on the output shaft (0101) and has a first torsion arm and a second torsion arm. The first torsion arm is connected to the rotor cover plate (0107), and the second torsion arm is fixedly connected to the housing (0103). When the drive spring (0109) stops being energized and cools down to reset, the torsion spring (0106) applies a reverse torque to the rotor (0108) to drive the rotor (0108) and the output shaft (0101) back to the initial angle position.

7. The driver as claimed in claim 6, characterized in that, Also includes: A spacer (0105) is installed inside the housing (0103) to axially press the second torsion arm of the torsion spring (0106) connected to the housing (0103).

8. A driver system, characterized in that, include: The driver (01) as described in any one of claims 1 to 7; a coupling (02) for connecting the output shaft (0101) of the driver (01) to an external load; an angular displacement sensor (03) coaxially connected to the output shaft (0101) and / or the coupling (02) for real-time acquisition of the output angle of the driver and outputting an analog voltage signal; and a controller (04) electrically connected to the angular displacement sensor (03) and the drive spring (0109) for heating control of the drive spring (0109) and realizing closed-loop control of the driver (01).

9. The driver system as claimed in claim 8, characterized in that, The controller (04) includes: an angular displacement sensor acquisition circuit, used to protect and filter the analog voltage signal output by the angular displacement sensor (03) and output it to the analog-to-digital conversion module; a control minimum system, used to acquire the angle data converted by the analog-to-digital conversion module and execute the control algorithm to output a control signal; a power output heating drive circuit, used to generate a PWM signal according to the control signal output by the control minimum system and drive the power switching device to adjust the voltage and current applied to the drive spring (0109); and a communication circuit, used to communicate with the host computer.

10. A method for controlling an actuator based on a shape memory alloy driven spring, characterized in that, The system is applied to the drive system as described in claim 8 or 9, comprising the following steps: S1, angle acquisition: the angular displacement sensor (03) detects the mechanical angle of the output shaft (0101) in real time, outputs an analog voltage signal, which is processed by the angular displacement sensor acquisition circuit and input to the analog-to-digital conversion module of the controller (04) to obtain the current angle θ_cur; S2, target reception: the controller (04) receives the target angle setpoint θ_set sent by the host computer through the communication circuit; S3, cascade PID operation: the controller (04) executes the cascade PID control algorithm, the outer loop calculates the target heating amount or target current of the drive spring (0109) with the angle error (θ_set-θ_cur) as input, and the inner loop dynamically corrects the target heating amount or target current according to the temperature change rate of the drive spring (0109); S4, PWM modulation and heating drive: the controller (04) according to The cascaded PID calculation result generates a PWM signal, which adjusts the voltage and current applied to the drive spring (0109) through the power output heating drive circuit, so that the drive spring (0109) is heated and deformed, driving the rotor (0108) and the output shaft (0101) to rotate; S5, closed-loop correction: the controller (04) periodically collects the output of the angular displacement sensor (03), updates the current angle θ_cur, and corrects the duty cycle of the PWM signal until the angle of the output shaft (0101) reaches the target angle setting value θ_set; S6, reset control: when the driver needs to be reset, the controller (04) cuts off the current applied to the drive spring (0109), so that the drive spring (0109) is cooled and reset under the torque of the torsion spring (0106) and drives the rotor (0108) and the output shaft (0101) back to the initial angle position.

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