Flexible robot joint electromagnetic driver

Abstract

The invention discloses a flexible joint electromagnetic driver, and belongs to the technical field of bionic robots. The flexible robot joint electromagnetic driver comprises a stator module, a flexible connecting mechanism and a swing module. The stator module comprises a base and an electromagnetic coil fixed to the base. One end of the flexible connection mechanism is connected with the stator module, the other end of the flexible connection mechanism is connected with the swing module, and the flexible connection mechanism is a polypropylene imine film, a polyvinyl chloride plate or a spring steel sheet; the swing module comprises a permanent magnet corresponding to the electromagnetic coil, a force transmission unit and an execution unit, the permanent magnet is fixed to the force transmission unit, and the force transmission unit is connected with the execution unit. The adopted flexible connecting mechanism has the structural supporting and passive compliance characteristics, and through the integrated design of electromagnetic driving and the flexible connecting mechanism, the high-energy-density driving capacity is reserved, and compliance movement and impact buffering of the joint are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of bionic robots, and particularly to an electromagnetic driver for a flexible robot joint. Background Art

[0002] The limb joint systems of most organisms are composed of muscle-tendon tissues and joint structures working together. This bionic design endows organisms with multi-degree-of-freedom and self-adaptive movement capabilities. In the field of bionic robots, to reproduce this exquisite movement mechanism, currently two main technical routes are mainly adopted: traditional motor drive schemes and emerging artificial muscle drive schemes.

[0003] In the motor drive scheme, permanent magnet synchronous motors are widely used due to their high energy density and precise control characteristics. Its working principle is to drive the permanent magnet rotor through the rotating magnetic field generated by the stator winding, simulating the contraction-relaxation function of biological muscles. However, this scheme has significant limitations: First, traditional motors must rely on rigid bearings to support the rotor, which restricts joint movement to a single rotational degree of freedom and cannot simulate the compliance of biological joints; Second, the volume and weight of the motor are relatively large, and energy loss and motion hysteresis may also be introduced due to the transmission mechanism.

[0004] The artificial muscle drive scheme uses the intrinsic properties of smart materials to simulate biological muscles: Shape memory alloys can generate strain through thermally induced phase changes and are suitable for constructing tendon-like linear actuators, but their response speed is limited by the heat conduction rate (for example, Chinese Patent No. CN112357027A discloses a tensegrity bionic robotic fish driven by shape memory alloys, including a fish head, a tail fin, fish bones, and a driver. The drive system is an embedded fish bone mechanism drive system based on shape memory alloy drive, consisting of a helical shape memory alloy drive device, a controller, and a control circuit); Ionic polymer-metal composites can generate bending deformation under the action of an electric field and have the advantage of underwater self-adaptability, but the output force is small; Piezoelectric ceramic actuators can achieve fast response and precise positioning, but the working strain is small, and a magnification mechanism is required to achieve a practical displacement (S. Yan et al., "Recent advances in design, sensing, and autonomy of biomimetic robotic fish: a review," IEEE-ASME Trans. Mechatron., pp. 1–20, Oct. 2024, doi: 10.1109 / TMECH.2024.3469953.).

[0005] This "driving force - motion range - response speed" trade - off dilemma essentially stems from the simplified imitation of biological motion mechanisms in existing technical routes: the motor solution overly relies on rigid transmission, sacrificing the passive compliance of biological joints; while the artificial muscle solution, although retaining the compliant characteristics, fails to reproduce the high - power - density characteristics of skeletal muscles. Therefore, developing a new type of hybrid drive system that combines the high - energy characteristics of electromagnetic drive and the compliant characteristics of biological tissues has become an important direction to break through the current technical bottleneck. Summary of the Invention

[0006] The object of the present invention is to provide an electromagnetic driver for a flexible robot joint. The flexible connection mechanism adopted has both structural support and passive compliance characteristics. Through the integrated design of electromagnetic drive and flexible connection structure, it not only retains the high - energy - density driving ability but also realizes compliant joint motion and impact buffering.

[0007] To achieve the above - mentioned invention object, the present invention is realized through the following technical solutions: An electromagnetic driver for a flexible robot joint, the electromagnetic driver for the flexible robot joint includes a stator module, a flexible connection mechanism, and a swing module: The stator module includes a base and an electromagnetic coil fixed on the base; The flexible connection mechanism is connected to the stator module at one end and to the swing module at the other end. The flexible connection mechanism is a polypropylene imide film, a polyvinyl chloride plate, or a spring steel sheet; The swing module includes a permanent magnet corresponding to the electromagnetic coil, a force - transmitting unit, and an execution unit. The permanent magnet is fixed to the force - transmitting unit, and the force - transmitting unit is connected to the execution unit.

[0008] To solve the core problems in existing bionic drive technologies, namely, the lack of joint compliance caused by the traditional motor's reliance on rigid transmission and the insufficient driving power density of artificial muscles. The present invention integrates an electromagnetic driver with a flexible connection mechanism, which not only has a high - energy - density driving level similar to that of a motor but also has compliance, and can achieve performance similar to that of a biological joint (innovatively integrating the high - energy - density characteristics of electromagnetic drive and the passive compliance characteristics of biological tissues, breaking through the "driving force - compliance" performance trade - off bottleneck, and realizing efficient adaptive motion close to that of biological joints); effectively solving the inherent contradiction between the rigid transmission of traditional motors and the insufficient driving force of artificial muscles, and providing a joint solution for bionic robots that combines high - efficiency drive and environmental adaptability.

[0009] The working principle of the electromagnetic driver for the flexible robot joint provided by the present invention is as follows: The flexible connection mechanism functions similarly to the joint in a biological limb joint; an electromagnetic coil is installed in the stator module, and when positive and reverse currents are passed through the coil, positive and reverse magnetic fields can be generated inside the coil; there are permanent magnets in the swinging module, and the structural design makes the permanent magnets arranged in the electromagnetic coil of the stator module. When the magnetic field inside the electromagnetic coil changes, the permanent magnets will cause the swinging module to respond to the stator magnetic field, thus generating a swinging motion, and the swinging motion will drive the execution unit to complete corresponding actions.

[0010] The base is prepared by the process of stacking silicon steel sheets, and the electromagnetic coil is a copper coil. The process of stacking silicon steel sheets for the base helps to improve magnetic permeability and reduce iron loss; the electromagnetic coil group is composed of two groups of precisely wound copper coils, and the diameter of the copper wire, as well as the inner diameter, outer diameter, and height of the coil, can be adjusted according to different loads.

[0011] Further, the electromagnetic coil includes two groups of electromagnetic coils, and the two groups of electromagnetic coils are fixed in the preset slots of the base through an adhesive. For example, the two groups of electromagnetic coils can be fixed in the preset slots of the base through epoxy resin adhesive.

[0012] Further, the stator module includes a damping ring.

[0013] By providing a damping ring that can be installed according to requirements in the stator module, in the application scenario of a mechanical finger, the damping ring can resist the rebound of the execution unit, so that the execution unit can have a certain resistance when there is no current drive to maintain the current position; in the application scenarios of a bionic fish fin and a bionic bird wing, the damping ring can be not installed to ensure the requirement of high-frequency swinging.

[0014] Among them, the thickness of the flexible substrate can be adjusted according to the load.

[0015] Further, the flexible connection mechanism is selected from a spring steel sheet with a thickness of 0.1 mm, a polypropylene imide film with a thickness of 0.3 mm, or a polyvinyl chloride plate with a thickness of 0.2 mm.

[0016] Further, the swinging module includes two neodymium iron boron spherical permanent magnets, and the permanent magnets are fixed in the positioning cavity of the force transmission unit. Among them, the surfaces of the two neodymium iron boron spherical permanent magnets are nickel-plated.

[0017] The execution unit is a flexible machine fish tail fin, a bionic bird wing, or a bionic mechanical finger.

[0018] The flexible connection mechanism is respectively connected to the base in the stator module and the force transmission unit in the swinging module through an adhesive, and the force transmission unit and the execution unit in the swinging module are connected through screws or an adhesive. Among them, a micro stainless steel positioning pin is used to enhance mechanical stability.

[0019] The advantages of the present invention compared with the prior art are as follows: The integrated design of electromagnetic drive and flexible connection mechanism is adopted. High-energy-density drive is achieved by optimizing the magnetic circuit structure. At the same time, the flexible connection mechanism endows the joint with passive compliance characteristics, effectively buffering impacts and adapting to complex motion requirements, breaking through the performance contradiction between traditional rigid transmission and artificial muscle solutions; the device adopts a modular structure, and the modular structure supports the flexible configuration of damping rings, which can not only meet the static position holding requirements of scenarios such as bionic mechanical fingers, but also achieve high-frequency swinging of bionic fish fins. By adjusting the core components to adapt to different dynamic characteristics, the adaptability of application scenarios is significantly expanded; the row unit adapts to a variety of bionic components through detachable interfaces, and combined with the customized design of the substrate material and coil parameters, different load requirements are met. Brief Description of the Drawings

[0020] Figure 1 Schematic diagram of the structure of the flexible joint electromagnetic drive with a bionic fish fin as an example provided for Embodiment 1; Figure 2 Composition diagram of the structure of the flexible joint electromagnetic drive with a bionic fish fin as an example provided for Embodiment 1; Figure 3 Working principle diagram of the flexible joint electromagnetic drive with a bionic fish fin as an example provided for Embodiment 1; Figure 4 Schematic diagram of the structure of the flexible joint electromagnetic drive with a bionic bird wing as an example provided for Embodiment 2; Figure 5 Schematic diagram of the structure of the flexible joint electromagnetic drive with a bionic finger as an example provided for Embodiment 3; Figure 6 Composition diagram of the structure of the flexible joint electromagnetic drive with a bionic finger as an example provided for Embodiment 3. Detailed Embodiments

[0021] The following further elaborates on the content of the present invention in conjunction with the drawings and embodiments.

[0022] Embodiment 1 Flexible Joint Electromagnetic Drive with a Bionic Fish Fin as an Example As Figure 1 shown and Figure 2 shown, specifically provided in this embodiment includes a stator module 1, a flexible connection mechanism 2, and a swinging module 3: The stator module 1 includes a base 4 and an electromagnetic coil 5: The base 4 adopts the process of stacking silicon steel sheets, and the electromagnetic coil 5 is composed of two groups of precisely wound copper coils. The electromagnetic coil 5 is fixed in the preset slot of the base 4 through epoxy resin adhesive; The flexible connection mechanism 2 is a polypropylene imide film 6 with a thickness of 0.3 mm. The material is based on the load of the execution unit. One end of the substrate is connected to the base 4 in the stator module 1 through strong glue, and the other end is also bonded to the force transmission unit 8 in the swing module 3 using strong glue, supplemented by a micro stainless steel positioning pin to enhance mechanical stability; The swing module 3 includes two neodymium iron boron spherical permanent magnets 7, a force transmission unit 8, and an execution unit: The permanent magnets are surface nickel-plated and fixed in the positioning cavity of the aluminum alloy force transmission unit 8 through an adhesive; The force transmission unit 8 and the execution unit can be connected by screws or by an adhesive.

[0023] In the embodiment, the execution unit is a flexible machine fish tail fin 9.

[0024] As Figure 3 shown, the working process of the flexible joint electromagnetic actuator with a bionic fish fin as an example provided in this embodiment is as follows: Place the bionic fish fin in water and apply a sinusoidally varying current to the electromagnetic coil, with the current amplitude and frequency controllable. At this time, a changing magnetic field will be generated in the coil. According to the right-hand rule, when the electromagnetic coil is energized, it will generate a magnetic field along the Dir-S direction. The magnetic field of the electromagnetic coil interacts with the magnetic field of the spherical permanent magnet, aligning the magnetic field of the spherical permanent magnet from the Dir-M direction to the Dir-S direction, thereby generating an electromagnetic torque. Therefore, applying sinusoidally varying clockwise and counterclockwise currents to the coil will induce a periodic change in the electromagnetic torque, thus driving the oscillation of the spherical permanent magnet. The oscillation of the spherical permanent magnet will drive the movement of the bionic fish fin, and the bionic fish fin will generate a forward propulsion force in the water, driving the robotic fish to swim.

[0025] Embodiment 2 Flexible joint electromagnetic actuator with a bionic bird wing as an example The difference from Embodiment 1 is that, as Figure 4 shown, the execution unit of this embodiment is a bionic bird wing 10. Among them, the material of the flexible substrate 6 is a polyvinyl chloride plate with a thickness of 0.2 mm.

[0026] Embodiment 3 Flexible joint electromagnetic actuator with a bionic mechanical finger as an example The difference from Embodiment 1 is that, as Figure 5 shown, the execution unit of this embodiment is a bionic mechanical finger 11, and there is a damping ring 12 (as Figure 6 shown) that can be installed according to requirements in the stator module 1. In the application scenario of the mechanical finger, the damping ring can resist the rebound of the execution unit, enabling the execution unit to have a certain resistance when there is no current drive to maintain the current position.

Claims

1. A flexible robotic joint electromagnetic driver, characterized in that, The electromagnetic driver of the flexible robot joint includes a stator module, a flexible connection mechanism, and a swing module: The stator module includes a base and an electromagnetic coil fixed on the base; The flexible connection mechanism is connected to the stator module at one end and the swing module at the other end. The flexible connection mechanism is a polypropylene imide film, a polyvinyl chloride plate, or a spring steel sheet; The swing module includes a permanent magnet corresponding to the electromagnetic coil, a force transmission unit, and an execution unit. The permanent magnet is fixed to the force transmission unit, and the force transmission unit is connected to the execution unit.

2. The electromagnetic actuator for a flexible robot joint according to claim 1, wherein The base is prepared by a process of stacking silicon steel sheets, and the electromagnetic coil is a copper coil.

3. The electromagnetic actuator for a flexible robot joint according to claim 1, characterized in that, The electromagnetic coil includes two groups of electromagnetic coils, and the two groups of electromagnetic coils are fixed in the preset slots of the base by an adhesive.

4. The electromagnetic driver of the flexible robot joint according to claim 1, wherein The stator module includes a damping ring.

5. The electromagnetic driver of the flexible robot joint according to claim 1, characterized in that The flexible connection mechanism is selected from a spring steel sheet with a thickness of 0.1 mm, a polypropylene imide film with a thickness of 0.3 mm, or a polyvinyl chloride plate with a thickness of 0.2 mm.

6. The electromagnetic actuator for the flexible robot joint according to claim 1, characterized in that, The swing module includes two neodymium iron boron spherical permanent magnets, and the permanent magnets are fixed in the positioning cavity of the force transmission unit.

7. The electromagnetic driver of the flexible robot joint according to claim 1, characterized in that, The execution unit is a flexible fish tail fin, a bionic bird wing, or a bionic mechanical finger.

8. The electromagnetic actuator of the flexible robot joint according to claim 1, characterized in that, The flexible connection mechanism is connected to the base in the stator module and the force transmission unit in the swing module by an adhesive respectively. The force transmission unit and the execution unit in the swing module are connected by screws or an adhesive.

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