Linear actuator

Abstract

The linear actuator comprises a control part, a driving part and a movable part, the control part sends a driving control instruction to the driving part, and the driving part sends a displacement operation instruction to the movable part so that the movable part can execute corresponding displacement operation; the control part also obtains a control command sent by the main controller and sends data to the main controller; at least one end of the linear actuator is provided with a standard connecting end so as to be matched with standard connecting ends of other linear actuators and / or matched with standard connecting ports of connecting nodes between at least two linear actuators, and detachable connection is achieved. The method can support distributed intelligent control, has good cooperative work capability, can realize local closed-loop control, improves control precision and system stability, can also realize rapid deployment and system integration, and has good engineering expansion capability and application versatility.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of mechanical and electronic technology, and in particular to a linear actuator. BACKGROUND

[0002] A linear actuator is an actuator that converts energy into linear motion, often used in automation equipment that requires precise push-pull control. By adjusting the input signal, the components of the linear actuator can be controlled to move in a straight line, thereby achieving automatic opening and closing, lifting, and pushing actions.

[0003] The mechanical part of an electric linear actuator is usually composed of a screw assembly, a slider (or push rod), a guide rail system, a bearing seat, and a shell. Among them, the screw assembly is the core component of linear motion, and the common types include trapezoidal screw and ball screw. The former has self-locking ability and is suitable for scenarios where the position remains unchanged. The latter has low friction and high efficiency, making it suitable for high-speed and high-precision motion requirements. The slider is connected to the screw through a nut, and when the screw is rotated by the motor, the slider moves in a straight line in the axial guide mechanism (such as linear guide, sleeve guide, aluminum profile channel, etc.). The guide rail system is used to suppress the shaking and yawing of the slider during movement, ensuring the stability and repeatability of its motion. In addition, travel limiting devices such as limit switches, bumpers, or physical stops are often installed at both ends to prevent mechanical impact caused by over-travel of the slider. The entire mechanical structure is usually packaged in an aluminum alloy or stainless steel shell to improve environmental adaptability, corrosion resistance, and overall rigidity, thereby meeting the reliability and durability requirements of industrial automation equipment.

[0004] In summary, the existing technology has the following outstanding problems in realizing the cooperative control of multiple linear actuators:

[0005] (1) The actuator body is highly dependent on the main control instruction and lacks independent control capability, resulting in poor system reliability;

[0006] (2) There is a lack of communication mechanism between actuators, making it impossible to share states and real-time coordination between actuators;

[0007] (3) The control accuracy of the actuator depends on open-loop or one-way feedback, resulting in slow response and weak disturbance adaptation ability;

[0008] (4) The interconnection structure between actuators is not unified, limiting the scalability and deployment efficiency of the system.

[0009] Therefore, the present application is proposed. SUMMARY

[0010] The application aims to provide a linear actuator, which has the ability of independent control and can improve the scalability and control accuracy, thereby solving the technical problems in the prior art.

[0011] The application aims to achieve the above-mentioned purposes through the following technical solutions.

[0012] A linear actuator comprises a control component, a driving component and a movable component, wherein:

[0013] The control component is connected with the driving component and sends a driving control instruction to the driving component; the driving component is connected with the movable component and sends a displacement operation instruction to the movable component, so that the movable component performs a corresponding displacement operation; the control component is also connected with a master controller to obtain a control command sent by the master controller, generate the driving control instruction based on the control command, and send operation parameter data of the movable component and / or the driving component to the master controller.

[0014] Moreover, a standard connection end is arranged at at least one end of the linear actuator, which is matched with a standard connection end of another linear actuator and / or a standard connection port of a connection node between at least two linear actuators, so as to realize detachable connection between the standard connection ends of the linear actuators.

[0015] Preferably, the control component is configured based on a double proportional-integral-derivative (PID) control structure and comprises an inner loop and an outer loop arranged in parallel; the inner loop takes current feedback as a control object, suppresses load disturbance by adjusting driving current in real time, compares current motor feedback current with target current, adjusts a duty cycle of a pulse width modulation (PWM) signal, drives the motor to output corresponding torque, and controls displacement of the movable component; the outer loop takes angular displacement and speed information collected by a magnetic encoder as feedback, realizes tracking of position and speed through PID adjustment, compares a deviation between current speed data and a target control parameter, and outputs a given target current, wherein the target control parameter is used to represent a displacement change target and a speed change target of the movable component.

[0016] Preferably, the standard connection end comprises a standard electrical interface and a standard mechanical connection interface; the control component further comprises an operation parameter acquisition part for acquiring operation parameters of the movable component and / or the driving component; and the control component determines the driving control instruction based on the operation parameters of the movable component and / or the driving component acquired; the operation parameters comprise driving parameters, load states and / or abnormal fluctuation information, and the driving parameters comprise current speed and driving current of the motor.

[0017] The control component controls the process of the movable component, including: based on the current rotating speed, driving current and target control parameter of the motor, determining the current driving control instruction by using a closed-loop PID control algorithm, so as to drive the motor to output corresponding torque based on the current driving control instruction by adjusting the duty cycle of the PWM signal, and drive the movable component to perform corresponding displacement operation, the target control parameter is used to represent the displacement change target and speed change target of the movable component; and the control component generates the driving control instruction in the following manner:

[0018] The control component generates and outputs the corresponding driving control instruction in real time according to the pre-set control strategy independently;

[0019] And / or,

[0020] The control component generates the corresponding driving control instruction based on the control command after receiving the control command from the main controller;

[0021] And / or,

[0022] The control component generates the corresponding driving control instruction based on the pre-set control strategy locally and the control command obtained from the main controller.

[0023] Preferably, the driving component includes:

[0024] An electromagnetic driving component, a hydraulic driving component, a pneumatic driving component, an electric driving component, a shape memory alloy driving component or a piezoelectric ceramic driving component.

[0025] Preferably, when the driving component is an electric driving component, the control component includes a motor driving part, a controller area network (CAN) transceiver and a controller unit, wherein:

[0026] The motor driving part is connected with the motor driving the movable component to perform displacement operation instruction, so as to control the motor to operate the form of the movable component;

[0027] The CAN transceiver is used as a communication circuit, for realizing information communication between the linear actuator and the main controller, so that each linear actuator reports the running parameters of the movable component and / or the driving component collected on the CAN bus, and receives the control command issued by the main controller; and for data transmission, state synchronization and instruction coordination between the linear actuators;

[0028] The controller unit obtains the driving control instruction for the movable component based on the information received through the CAN transceiver, and outputs to the motor driving part;

[0029] The controller area network (CAN) transceiver is also responsible for sending operation parameter data of the movable component and / or driving component to the main controller, and the operation parameter data of the corresponding movable component and / or driving component includes displacement, speed, current, limit state and / or force feedback data.

[0030] Preferably, the motor end is also provided with a corresponding magnetic encoder for collecting angular displacement information of the motor shaft and calculating the current rotating speed of the motor based on the angular displacement information of the motor shaft.

[0031] Preferably, the movable component includes an extension rod, a screw rod and a gear box, the gear box is connected with the motor, and the output shaft of the gear box is connected with the screw rod and drives the rotation of the screw rod, the screw rod includes screw rod segments with opposite screw directions at two ends, and the two screw rod segments are connected to two symmetrically arranged extension rods through two corresponding nuts, respectively, when the motor works, the two nuts at the two ends of the screw rod drive the two extension rods to move in opposite directions synchronously, thereby realizing the extension or shortening displacement operation of the movable component.

[0032] Preferably, the extension rod is provided with an inner wall conductive connection at the distal end, the inner wall conductive connection is connected with a distal power line; the inner wall conductive connection at the distal end extends to the proximal end and an outer wall conductive connection point through a conductive metal sheet, and forms a sliding electrical contact with an inner wall conductive metal sheet arranged on the shell, the proximal conductive connection point is connected with the control component for power supply, and the distal conductive connection point is connected with an external power supply; the screw rod is provided with a sleeve, and the end of the sleeve is connected with a hollow metal pipe through a thread, and the hollow metal pipe is also fixedly connected with the extension rod; the extension rod and the shell are also provided with a limit switch triggering structure for controlling the displacement range of the extension rod.

[0033] Preferably, the limit switch triggering structure includes a copper sheet arranged on the outside of the extension rod, two limit switch grooves arranged on the inner wall of the shell of the linear actuator and proximal and distal ends, a wire embedded in the switch groove and a vertical spring needle installed in the switch groove, when the extension rod moves to the limit position, the copper sheet triggers the spring needle to close to form a conduction path and sends a limit signal to the control component to control the motor to stop running.

[0034] Preferably, the linear actuator further includes a displacement guide rail, the displacement guide rail is arranged at the displacement track of the movable component, and the control component drives the movable component to change the corresponding position form in the shortest path and / or optimal acceleration based on the current control instruction, so as to realize the change of the connection form of the connection member.

[0035] Compared with the prior art, the linear actuator provided by the application can support distributed intelligent control, has good cooperative work capability, can realize local closed-loop control, and improves control precision and system stability; the structure state sensing and feedback regulation capability can be improved based on the setting of the CAN bus; and due to the unified communication protocol, standard connection end and modular structure design, the user can flexibly increase or decrease the number of the actuator according to task requirements, realize rapid deployment and system integration, and has good engineering expansion capability and application versatility. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed to be used in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0037] Figure 1 The implementation principle block diagram of the linear actuator provided by the embodiment of the application is shown in the figure.

[0038] Figure 2 The structure schematic diagram of the linear actuator provided by the embodiment of the application is shown in the figure. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the application will be described clearly and completely in combination with the drawings in the embodiments of the application. Obviously, the described embodiments are only some embodiments of the application, but not all the embodiments of the application, which do not constitute a limitation on the application. Based on the embodiments of the application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the application.

[0040] Firstly, the terms possibly used in the text are explained as follows:

[0041] The term "and / or" means either of the two or both can be realized at the same time, for example, X and / or Y means three cases including "X" or "Y" or "X and Y".

[0042] The terms "include", "contain", "have", "possess" or other similar semantic descriptions should be interpreted as non-exclusive inclusion. For example: including certain technical feature elements (such as raw materials, components, ingredients, carriers, dosage forms, materials, sizes, parts, components, mechanisms, devices, steps, processes, methods, reaction conditions, processing conditions, parameters, algorithms, signals, data, products or articles, etc.) should be interpreted as not only including the explicitly listed certain technical feature elements, but also including other technical feature elements not explicitly listed but known in the art.

[0043] The term "consisting of" shall mean excluding any element, ingredient, component, or step not specified. If the term "consisting of" is used in the claims, the term shall be interpreted in accordance with the doctrine of claim limitation independently from the specification of a separate list of technical features. If the term "consisting of" is used in a clause of the claims, the term shall be interpreted in accordance with the doctrine of claim limitation only in that clause, the elements recited in other clauses not being excluded from the overall claim.

[0044] The term "mass parts" is used to express the mass ratio relationship between components, for example: if it is described that X component is x mass parts and Y component is y mass parts, it means that the mass ratio of X component to Y component is x:y; 1 mass part can represent any mass, for example: 1 mass part can represent 1 kg or 3.1415926 kg, etc. The sum of the mass parts of all components does not necessarily equal 100 parts, and can be greater than 100 parts, less than 100 parts, or equal to 100 parts. Unless otherwise specified, the parts, proportions, and percentages described herein are by mass.

[0045] Unless otherwise defined, the terms "mounting", "connected", "connecting", "fixed", and the like, are to be construed in a broad sense, for example: can be fixed connection, can also be detachable connection, or integral connection; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in this article can be understood according to the specific circumstances.

[0046] When the concentration, temperature, pressure, size or other parameters are expressed in the form of a numerical range, the numerical range should be understood as specifically disclosing all ranges formed by any pair of upper limit value, lower limit value, preferred value in the numerical range, regardless of whether the range is explicitly recited; for example, if the numerical range "2-8" is recited, the numerical range should be interpreted as including "2-7", "2-6", "5-7", "3-4 and 6-7", "3-5 and 7", "2 and 5-7", etc. ranges. Unless otherwise specified, the numerical ranges recited herein include all integers and fractions within the numerical range, both the end values.

[0047] The terms "central", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like indicate the orientation or positional relationship shown in the drawings, which are only for the convenience of description and simplification of description, and do not mean that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation herein.

[0048] A linear actuator provided by the present application is described in detail below. The contents not described in detail in the embodiments of the present application belong to the prior art known to those skilled in the art. If no specific conditions are specified in the embodiments of the present application, the conditions are performed according to the conventional conditions in the art or the conditions recommended by the manufacturer. If no manufacturer is specified for the reagents or instruments used in the embodiments of the present application, they are all conventional products that can be purchased on the market.

[0049] In view of the defects of the linear actuator system in the prior art in terms of multi-actuator cooperative control, feedback response, structural integration and expandability, the embodiments of the present application specifically provide a linear actuator, as shown in Figure 1 which can include a control component, a driving component and a movable component, wherein:

[0050] (1) The control component is connected with the driving component and sends a driving control instruction to the driving component, the driving component is connected with the movable component and sends a displacement operation instruction to the movable component to make the movable component perform a corresponding displacement operation; the control component is also connected with a host controller to obtain a control command sent by the host controller, and generates the driving control instruction based on the control command and sends operation parameter data of the movable component and / or the driving component to the host controller;

[0051] That is, the control component has multiple control modes in actual operation, which can specifically include:

[0052] Firstly, the control component can independently generate and output a driving control instruction matching the current working state in real time according to a pre-set control strategy without receiving an external instruction, so as to ensure that the system can also realize autonomous operation without intervention of the upper computer;

[0053] Secondly, the control component can also generate a corresponding driving control instruction directly based on the control command from the upper computer (i.e. the host controller) after receiving the control command, so as to realize centralized and unified scheduling and control of the system;

[0054] Thirdly, in the case of needing to balance autonomy and coordination, the control component can also generate driving control instructions on the basis of following a locally predetermined control strategy and in combination with corresponding control commands obtained from the upper computer, so as to ensure autonomous stable operation of the system while realizing collaborative control with the upper computer, and further improve flexibility and reliability of overall operation.

[0055] That is, an independent control component is configured for each linear actuator, which can include a control board to construct a local closed-loop control system based on a PID (Proportional-Integral-Derivative) controller in combination with a magnetic encoder and current feedback, so as to realize high-precision independent control and fast dynamic response of each linear actuator without interrupting communication. Specifically, the control component is configured to adjust the linear actuator based on a double-PID control structure, which includes an inner loop and an outer loop arranged in parallel: the inner loop takes current feedback as a control object and quickly suppresses load disturbance by adjusting driving current in real time; the outer loop takes angular displacement and speed information collected by the magnetic encoder as feedback, and realizes accurate tracking of position and speed through PID adjustment. The cooperative control of the inner and outer loops forms a double-channel feedback path, which is input into a built-in PID control algorithm module of the control component, so as to effectively improve the control stability and tracking accuracy of the linear actuator under load disturbance, operation fluctuation and slight adjustment.

[0056] Specifically, the movable component can be provided with a displacement guide rail arranged at a displacement track of the movable component to guide the running direction of the movable component.

[0057] (2) A standard connection end is arranged at at least one end of the linear actuator, which matches with a standard connection end of another linear actuator and / or matches with a standard connection port of a connection node between at least two linear actuators, so as to realize detachable connection between the standard connection ends of the linear actuators.

[0058] Specifically, a unified communication protocol, a standard electrical interface and a mechanical installation reference design can be adopted between the linear actuators, that is, each linear actuator includes a standard connection end, which can include a standard electrical interface and a standard mechanical connection interface, etc., so that multiple linear actuators can be flexibly expanded, replaced and reconfigured in any form as needed, so as to improve system engineering practicability and maintenance efficiency.

[0059] Further, the corresponding control component can further include an operation parameter acquisition part for acquiring operation parameters of the movable component and / or the driving component; and the control component determines the driving control instruction based on the acquired operation parameters of the movable component and / or the driving component.

[0060] In the linear actuator provided by the embodiment of the application, the driving component can be, but is not limited to, an electromagnetic driving component, a hydraulic driving component, a pneumatic driving component, an electric driving component, a shape memory alloy driving component or a piezoelectric ceramic driving component, etc.

[0061] Further, if the driving component is an electric driving component, the control component can include a motor driving part, a controller area network (CAN) transceiver and a controller unit, wherein:

[0062] The motor driving part is connected with a motor for driving the movable component to execute a displacement operation instruction, to control the motor to operate the form of the movable component;

[0063] The CAN transceiver serves as a communication circuit, for realizing information communication between the linear actuator and the main controller, so that each linear actuator reports the acquired operation parameters of the movable component and / or the driving component on the CAN bus, and receives the control command issued by the main controller; and for data transmission, state synchronization and instruction coordination between the linear actuators;

[0064] The controller unit processes the information received through the CAN transceiver to obtain the driving control instruction for the movable component, and outputs the driving control instruction to the motor driving part. That is, a differential communication structure based on the CAN bus is introduced in the linear actuator, to realize high-speed data transmission, state synchronization and instruction coordination between the linear actuator nodes, and support real-time interaction between the main controller node and the linear actuators, thereby significantly improving the collaborative efficiency and fault tolerance of the system; specifically, each linear actuator can actively report its acquired operation data (i.e., the operation parameters of the movable component and / or the driving component, such as displacement, speed, current, limit state, force feedback, etc.) on the CAN bus, to assist the main controller to realize global monitoring, strategy optimization and abnormal early warning, and provide reliable parameter data basis for intelligent scheduling control.

[0065] The linear actuator provided by the embodiment of the present application can include an extension rod, a screw rod and a gear box, the gear box is connected with a motor, and an output shaft of the gear box is connected with the screw rod and drives the screw rod to rotate, the screw rod includes screw rod segments with opposite screw directions at two ends, and the screw rod segments are connected to two symmetrically arranged extension rods through two corresponding nuts respectively, when the motor works, the two nuts at the two ends of the screw rod drive the two extension rods to move in opposite directions synchronously, so that the movable component performs the displacement operation of extension or shortening.

[0066] The surface of the screw rod can be provided with a sleeve, and the end of the sleeve is connected with a hollow metal pipe through screw connection, and the hollow metal pipe is also fixedly connected with the extension rod.

[0067] The extension rod is provided with an inner wall conductive connection at the distal end, the inner wall conductive connection is connected with a distal end power supply line, the inner wall conductive connection at the distal end extends to a proximal end and an outer wall conductive connection point through a conductive metal sheet, and the proximal end and the outer wall conductive connection point form sliding electrical contact with the inner wall conductive metal sheet arranged on the shell, the proximal end conductive connection point is connected with a control component for power supply, and the distal end conductive connection point is connected with an external power supply.

[0068] Further, the extension rod and the shell are also provided with a limit switch triggering structure for controlling the displacement range of the extension rod. The limit switch triggering structure can include: a copper sheet arranged on the outside of the extension rod, two limit switch grooves arranged on the inner wall of the shell of the linear actuator, wires embedded in the switch grooves and vertical spring pins installed in the switch grooves, when the extension rod moves to the limit position, the copper sheet triggers the spring pins to close to form a conduction path and sends a limit signal to the control component to control the motor to stop working.

[0069] Based on the structural design of the linear actuator, the bottleneck of the existing linear actuator system in intelligent control, network communication and modular integration can be effectively broken through, and the linear actuator can be used as a component of a variable geometry truss to provide a high-performance, scalable and adaptable technical solution for multi-axis cooperative control of complex structures such as variable geometry truss robots.

[0070] In order to facilitate the understanding of the present application, the specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0071] The linear actuator provided by the embodiment of the present application can be applied to a multi-linear actuator of a variable geometry truss robot, and can be used as a coordinated control system to realize multi-axis linkage, structure stretching and contraction and geometric deformation control of the mechanism, so as to adapt to different task requirements and complex application environments.

[0072] In the linear actuator, each linear actuator is equipped with an independent control board (i.e., a control component) in the specific implementation process, and the actuating structure (i.e., a driving component and a movable component) of the linear actuator can include a motor, a reduction gear box and a screw rod mechanism. The motor drives the output shaft to rotate after being decelerated by the gear box, and the output shaft is connected with screw rod assemblies with opposite screw directions at both ends. The corresponding screw rods can convert the rotary motion into axial linear motion by cooperating with the nuts. Since the screw rods have opposite screw directions, synchronous extension or synchronous shortening of the two screw rod ends can be realized under the same rotary drive, so that the connection structure realizes mirror image linear driving.

[0073] In the linear actuator, each linear actuator is equipped with an independent control board (i.e., a control component) in the specific implementation process, and the actuating structure (i.e., a driving component and a movable component) of the linear actuator can include a motor, a reduction gear box and a screw rod mechanism. The motor drives the output shaft to rotate after being decelerated by the gear box, and the output shaft is connected with screw rod assemblies with opposite screw directions at both ends. The corresponding screw rods can convert the rotary motion into axial linear motion by cooperating with the nuts. Since the screw rods have opposite screw directions, synchronous extension or synchronous shortening of the two screw rod ends can be realized under the same rotary drive, so that the connection structure realizes mirror image linear driving.

[0074] Further, a copper sheet region with a quarter of a circumferential width of one centimeter can be arranged outside the middle of the extension rod as a limit switch triggering structure, and two limit switch grooves with proximal and distal ends can be arranged on the inner wall of the housing of the linear actuator, and a wire and a horizontally arranged spring needle are embedded in the grooves. With the movement of the extension rod, when the copper sheet triggers the spring needle to form a closed path, a limit signal is sent to the control board to identify that the current stroke has reached the limit and to forcibly stop the drive to prevent overshoot damage. Moreover, a guide rail structure (i.e., a displacement guide rail) can be arranged between the inner wall of the housing and the extension rod to guide the movable component of the linear actuator to move stably along the trajectory of the fixed guide rail structure, avoiding shaking and jamming.

[0075] In the linear actuator, a magnetic encoder can be installed at the end of the motor to collect the angular displacement information of the motor rotating shaft in real time, and the current rotating speed of the motor can be calculated based on the angular displacement information. Specifically, the magnetic encoder can detect the change of the rotating magnetic field by the Hall effect principle and output corresponding pulse signals. After the pulse signals are processed by the signal acquisition module on the control component, accurate speed data and position estimates such as displacement and speed can be obtained. The control component can also monitor the motor driving current in real time to obtain the load state or abnormal fluctuation information, which can be used as an important basis for system response adjustment.

[0076] In the control component, the corresponding control strategy can adopt a double closed-loop PID control algorithm based on speed data (such as the current speed of the motor) and motor drive current feedback to determine the corresponding control instruction, wherein the proportional (P), integral (I) and differential (D) parameters can be configured according to the system response characteristics. Specifically, the double PID control structure includes parallel inner and outer loops: the inner loop constructs a current closed loop based on motor drive current feedback, and in the corresponding processing process based on the PID control algorithm, the current motor feedback current and the target current (i.e. the value of the target current output by the outer loop) can be continuously compared, the duty cycle of the PWM (pulse width modulation) signal is adjusted, the motor outputs appropriate torque, and the precise displacement control of the linear actuator is realized; the outer loop constructs a speed / position closed loop based on the speed data (such as the current speed of the motor) and position information collected by the magnetic encoder, continuously compares the deviation between the current speed data and the target instruction (i.e. the target control parameter, which is used to represent the displacement change target and speed change target of the movable component), and outputs the value of the given target current. The PWM signal is generated by a timer module in the control component, and its frequency and resolution meet the requirements of high-speed response and motor drive chip characteristics. In order to realize efficient cooperation between multiple linear actuators in the system, all control boards (i.e. control components) can be connected to the host computer (i.e. the upper computer) through a CAN bus (Controller Area Network). The bus uses differential signal transmission, and all control boards on the linear actuators of the nodes can be connected in parallel through the CAN_H and CAN_L signal lines to form a multi-node bus topology. The CAN transceiver chip is used to convert the serial data of the MCU (controller) on the control board into a differential signal, and to realize the isolation and matching of the physical layer and the protocol layer. The communication cable adopts a twisted pair structure with impedance matching to reduce common mode interference, improve data integrity and transmission stability, and at the same time, 120Ω matching resistors are connected at both ends of the bus to suppress signal reflection and end point fluctuation, ensuring the communication reliability of the system in long distance or multi-node operation.

[0077] On the corresponding linear actuator, an MCU (such as STM32F103 single-chip microcomputer, etc.) can be integrated on the corresponding control board to be responsible for local execution of actuation logic, including magnetic encoder data acquisition, real-time PID control, current monitoring, motor drive signal output, limit protection judgment, and data communication based on CAN protocol, etc. The CAN software protocol adopts a standard frame format, and supports priority arbitration and event triggered response based on identifiers (IDs) between nodes. The host computer (i.e. the upper computer) can broadcast or send target displacement instructions, working mode settings or state query requests through the CAN bus, and each control board receives the instructions and analyzes the target position according to the instruction content and immediately responds dynamically to adjust the control screw to change the position with the shortest path and optimal acceleration.

[0078] Through the system architecture constructed based on the linear actuator, each linear actuator has independent closed-loop control capability, and can participate in unified system-level coordination tasks. The distributed implementation of the control logic enables the system to have certain redundancy and adaptability when facing node-level fluctuations or failures, thereby meeting the multi-task execution requirements of multi-axis linkage, adaptive structural deformation and environmental response, and being especially suitable for application scenarios such as variable geometry truss robots with complex dynamic structures. Further, the system can combine intelligent control strategies such as reinforcement learning to achieve better path planning and response strategies, improve the adaptability and environmental adaptability of the system, and is especially suitable for deployment in complex terrain, unstructured environments or multi-functional collaborative tasks, and has good scalability and engineering application value.

[0079] As shown in Figure 2 The implementation structure of the linear actuator provided by the embodiment of the application can include key mechanical components such as a shell (1), an extension rod (2), a motor (3), a gear box (4) and a lead screw (5). Each actuator is equipped with an independent control board (i.e., a control component) to realize electrically controlled closed-loop control.

[0080] The motor (3) is fixedly installed in the shell (1) and reduces the high-speed output to low-speed high-torque power through the built-in gear box (4); the output shaft of the gear box (4) is connected with the lead screw (5) and drives the rotation of the lead screw (5); the one-piece structure of the lead screw (5) includes lead screw segments with opposite screw directions at both ends, which are connected to two symmetrically arranged extension rods (2) through two corresponding nuts. When the motor (3) rotates in one direction, the nuts at both ends of the lead screw (5) drive the two extension rods (2) to move in opposite directions synchronously, completing the mirror image collaborative action of elongation or shortening, thereby realizing multi-axis linkage configuration adjustment.

[0081] In order to ensure the movement precision and coaxiality of the lead screw (5), a transparent sleeve can be sleeved on the outer surface of the lead screw (5), which can protect the lead screw from dust and oil pollution; the end of the lead screw (5) is connected with a hollow metal pipe through threads, and the metal pipe is fixedly connected with the extension rod (2) to form the moving output end of the actuator. Copper sheets are laid in the extension rod (2), the copper sheets are connected with power lines through welding and extended to the outer wall of the proximal end, and the spring needle forms sliding electrical contact with the conductive copper sheet arranged on the inner wall of the shell (1), realizing the cross-arm transmission of the power supply in the reciprocating process and ensuring the continuous power supply of the control circuit.

[0082] Further, the outer wall of the extension rod (2) can be provided with a copper sheet region with a width of one centimeter and a quarter of the circumference at a position close to the middle of the extension rod (2) as a limit switch triggering structure; and the inner wall of the shell (1) is provided with two limit switch grooves with proximal and distal ends, wires are embedded in the switch grooves, and vertical spring pins are installed; when the extension rod (2) moves to the limit position, the copper sheet triggers the horizontal spring pin to close to form a conduction path, thereby sending a limit signal to the control panel, and the control system stops the motor (3) from continuing to operate to avoid damage caused by structure exceeding the limit.

[0083] In addition, in order to ensure the stability and guiding accuracy of the extension rod (2) during movement, a pair of guide rail structures can be further provided on the inner wall of the shell (1) along the extension direction, so as to cooperate with the corresponding slide rail surface on the outer side of the extension rod (2), limit the radial shaking and provide accurate axial guidance.

[0084] As can be seen from the above, the linear actuator provided by the application can produce the following technical effects:

[0085] (1) The control component can support distributed intelligent control, thereby having good cooperative work capability;

[0086] That is, each linear actuator is integrated with an independent control panel (i.e., a control component), which can be connected in communication with a master controller and other actuators through a CAN bus, so as to realize data synchronization and coordinated control among multiple nodes (each linear actuator as a node); the architecture system based on the linear actuator can effectively overcome the problems of large original communication bottleneck, high response delay and poor expansibility of the centralized control system used in the traditional architecture, and can be well applied to application scenarios with high requirements for structural coordination in a multi-degree-of-freedom architecture system.

[0087] (2) Local closed-loop control can be realized to improve control accuracy and system stability;

[0088] That is, the control panel of each linear actuator can independently obtain corresponding real-time running parameters such as speed data and current feedback information based on a magnetic encoder, and can execute a local PID control algorithm based on the running parameters to realize high-precision closed-loop adjustment of the screw displacement; the closed-loop control method has fast response speed and strong robustness, and can effectively reduce the motion error caused by load disturbance or instruction delay, and ensure stable operation of the system in a non-stationary environment.

[0089] (3) Intelligent adjustment and self-adaptive capability are provided to adapt to complex task changes;

[0090] Specifically, in combination with intelligent algorithms such as reinforcement learning, the action strategy of the linear actuator can be dynamically optimized according to environmental feedback, the collaborative efficiency and resource allocation capability between multiple linear actuators are improved, and thus the adaptability and response capability of the system (such as a robot system) constructed by the multiple linear actuators to irregular terrains, dynamic obstacles and structural deformation tasks are enhanced.

[0091] (4) improving the structure state perception and feedback regulation capability;

[0092] That is, through CAN bus communication, each actuator can upload the running state (such as the current telescopic displacement, limit state, current change, etc.) of itself to the main controller (i.e., the upper computer) in real time, so as to provide multi-dimensional perception data support for global decision-making, which is helpful to realize the functions of structure state monitoring, abnormal identification and system protection, etc.

[0093] (5) enhancing the modular expansion and engineering practicability;

[0094] Since the linear actuator provided by the embodiment of the present application can adopt a unified communication protocol, standard connection terminals (such as standard electrical interfaces, etc.) and a modular structure design, the user can flexibly increase or decrease the number of actuators according to the task requirements, realize rapid deployment and system integration, and has good engineering expansion capability and application versatility.

[0095] In summary, the present application not only solves the technical problems of communication limitation, insufficient feedback, low precision, etc. of the traditional linear actuator in multi-node cooperative control, but also has intelligent response, high-precision regulation and complex task adaptation capability, and is particularly suitable for complex systems such as variable geometry truss robots that require multi-axis cooperation and adaptive deformation, and has significant technical advantages and wide application prospects.

[0096] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any skilled person in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims. The information disclosed in the background section of this document is only intended to deepen the understanding of the overall background of the present application, and should not be regarded as acknowledging or implying in any form that the information constitutes prior art known to those skilled in the art.

Claims

1. A linear actuator, characterized in that, It includes control components, drive components, and movable components, wherein: The control component is connected to the drive component and sends drive control commands to the drive component. The drive component is connected to the movable component and sends displacement operation commands to the movable component so that the movable component performs corresponding displacement operations. The control component is also connected to the main controller to obtain control commands sent by the main controller, generate the drive control commands based on the control commands, and send the operating parameter data of the movable component and / or the drive component to the main controller. Furthermore, a standard connection terminal is provided at at least one end of the linear actuator, which is matched with the standard connection terminals of other linear actuators and / or with the standard connection ports of the connection nodes between at least two linear actuators, so as to enable a detachable connection between the standard connection terminals of the linear actuators.

2. The linear actuator according to claim 1, characterized in that, The control component is configured based on a dual proportional-integral-derivative (PID) control structure, and includes an inner loop and an outer loop arranged in parallel. The inner loop uses current feedback as the control object, and suppresses load disturbances by adjusting the drive current in real time. This includes comparing the current motor feedback current with the target current, adjusting the duty cycle of the pulse width modulation (PWM) signal, driving the motor to output corresponding torque, and controlling the displacement of the movable component. The outer loop uses angular displacement and velocity information collected by a magnetic encoder as feedback quantities, and tracks position and velocity through PID control. This includes comparing the deviation between the current velocity data and the target control parameters, and outputting a given target current. The target control parameters characterize the target displacement and velocity changes of the movable component.

3. The linear actuator according to claim 1 or 2, characterized in that, The standard connection terminal includes a standard electrical interface and a standard mechanical connection interface; the control component also includes an operating parameter acquisition section for acquiring operating parameters of the movable component and / or the drive component; and the control component determines the drive control command based on the acquired operating parameters of the movable component and / or the drive component. The operating parameters include drive parameters, load status and / or abnormal fluctuation information, and the drive parameters include the current speed of the motor and the drive current. The process by which the control unit controls the movable component includes: determining the current drive control command based on the current speed, drive current, and target control parameters of the motor using a closed-loop PID control algorithm; and driving the motor to output corresponding torque by adjusting the duty cycle of the PWM signal based on the current drive control command, thereby driving the movable component to perform corresponding displacement operations. The target control parameters are used to characterize the target displacement change and target speed change of the movable component. Furthermore, the method by which the control unit generates the drive control command includes: The control component independently generates and outputs corresponding drive control commands in real time according to a pre-set control strategy; And / or, After receiving a control command from the main controller, the control component generates a corresponding drive control instruction based on the control command. And / or, The control unit generates corresponding drive control instructions based on the locally preset control strategy and the control commands obtained from the main controller.

4. The linear actuator according to claim 3, characterized in that, The driving component includes: Electromagnetic drive components, hydraulic drive components, pneumatic drive components, electric drive components, shape memory alloy drive components, or piezoelectric ceramic drive components.

5. The linear actuator according to claim 3, characterized in that, When the driving component is an electric driving component, the control component includes a motor drive section, a controller area network (CAN) transceiver, and a controller unit, wherein: The motor drive unit is connected to the motor that drives the movable component to execute displacement operation commands, so as to control the motor to operate the movable component in a certain form. The CAN transceiver serves as a communication circuit, enabling information communication between the linear actuator and the main controller. It allows each linear actuator to report the collected operating parameters of the movable parts and / or drive parts via the CAN bus, and to receive the control commands issued by the main controller. It is also used for data transmission, state synchronization, and command coordination among the linear actuators. The controller unit processes the information received via the CAN transceiver to obtain drive control commands for the movable component and outputs them to the motor drive section. The controller local area network (CAN) transceiver is also responsible for sending the operating parameter data of the movable parts and / or drive parts to the main controller. The corresponding operating parameter data of the movable parts and / or drive parts includes: displacement, speed, current, limit status and / or force feedback data.

6. The linear actuator according to claim 5, characterized in that, The motor end is also equipped with a corresponding magnetic encoder, which is used to collect the angular displacement information of the motor shaft and calculate and determine the current speed of the motor based on the angular displacement information of the motor shaft.

7. The linear actuator according to claim 5, characterized in that, The movable component includes an extension rod, a lead screw, and a gearbox. The gearbox is connected to a motor, and its output shaft is connected to the lead screw and drives it to rotate. The lead screw includes lead screw sections with opposite thread directions at both ends, which are respectively connected to two symmetrically arranged extension rods by cooperating with two corresponding nuts. When the motor is working, the nuts at both ends of the lead screw drive the two extension rods to move synchronously in opposite directions, realizing the displacement operation of the movable component to extend or shorten.

8. The linear actuator according to claim 7, characterized in that, The distal end of the extender rod is provided with an inner wall conductive connection, which is connected to the distal power line. The distal inner wall conductive connection extends to the proximal end and its outer wall conductive connection point through a conductive metal sheet, forming a sliding electrical contact with the inner wall conductive metal sheet provided on the outer shell. The proximal conductive connection point is connected to the control component to supply power, while the distal conductive connection point is connected to an external power source. The surface of the lead screw is provided with a sleeve, and its end is connected to a hollow metal tube by a thread. The hollow metal tube is also fixedly connected to the extender rod. The extender rod and the outer shell are also provided with a limit switch trigger structure to control the displacement range of the extender rod.

9. The linear actuator according to claim 8, characterized in that, The limit switch triggering structure includes: a copper sheet on the outside of the extension rod; two limit switch slots, one near the end and one far the end, on the inner wall of the linear actuator housing; a wire embedded in the switch slot and a vertical spring pin installed therein; when the extension rod moves to the limit position, the copper sheet triggers the spring pin to close, forming a conductive path and sending a limit signal to the control component to control the motor to stop running.

10. The linear actuator according to claim 3, characterized in that, It also includes a displacement guide rail, which is set at the displacement trajectory of the movable component, and the control component drives the movable component to change its position shape in a manner with the shortest path and / or optimal acceleration based on the current control command, so as to realize the change of the connection shape of the connecting component.

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