A flexible robot joint electromagnetic drive

Abstract

The application 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 on the base. The flexible connecting mechanism is connected with the stator module at one end and connected with the swing module at the other end, and the flexible connecting 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 flexible connecting mechanism adopted by the application has structural support and passive compliance characteristics. Through integrated design of electromagnetic driving and the flexible connecting mechanism, high energy density driving capability is retained, and joint compliance movement and impact buffering are realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bionic robots, and particularly relates to a flexible robot joint electromagnetic drive. BACKGROUND

[0002] The limb joint system of most living beings is composed of muscle-tendon tissue and joint structure in coordination, and this bionics design endows the living body with multi-degree-of-freedom and adaptive motion capability. In the field of bionic robots, in order to reproduce this exquisite motion mechanism, currently two technical routes are mainly adopted: a traditional motor driving scheme and an emerging artificial muscle driving scheme.

[0003] In the motor driving scheme, a permanent magnet synchronous motor is widely used due to its high energy density and precise control characteristics. Its working principle is to drive the permanent magnet rotor to move through the rotating magnetic field generated by the stator winding, simulating the contraction-dilation function of biological muscle. However, this scheme has significant limitations: first, the traditional motor must rely on rigid bearing to support the rotor, which leads to the joint motion being limited to a single rotational degree of freedom, and cannot simulate the compliance of biological joints; second, the motor has relatively large volume and weight, and may also introduce energy loss and motion hysteresis due to the transmission mechanism.

[0004] The artificial muscle driving scheme simulates biological muscle by using the intrinsic characteristics of intelligent materials: shape memory alloy can generate strain through thermal phase change, and is suitable for building tendon-like linear actuators, but its response speed is limited by the heat conduction rate (such as the Chinese patent with publication number CN112357027A discloses a shape memory alloy driven tensegrity bionic robot fish, including a fish head, a tail fin, a fish bone and a drive, and the drive system is an embedded fish bone mechanism drive system based on shape memory alloy drive, which is composed of a spiral shape memory alloy drive device, a controller and a control circuit); ion polymer-metal composite material can produce bending deformation under the action of an electric field, and has the advantage of underwater adaptability, but the output force is small; piezoelectric ceramic drive can realize fast response and precise positioning, but the working strain is small, and an amplification mechanism is needed to achieve 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 "drive-movement range-response speed" trade-off dilemma essentially stems from the simplified imitation of biological movement mechanisms in the prior art approach: the motor scheme relies too much on rigid transmission, sacrificing the passive compliance of biological joints; while the artificial muscle scheme, although retaining the compliance feature, fails to reproduce the high power density characteristic of skeletal muscle. Therefore, developing a new hybrid drive system that combines the high energy characteristics of electromagnetic drive and the compliance characteristics of biological tissue has become an important direction to break through the current technical bottleneck. SUMMARY

[0006] The purpose of the present application is to provide a flexible robot joint electromagnetic drive, which adopts a flexible connection mechanism with structural support and passive compliance characteristics, and through the integrated design of electromagnetic drive and flexible connection structure, it not only retains high energy density driving capability, but also realizes joint compliant movement and impact buffering.

[0007] To achieve the above-mentioned purpose of the application, the technical scheme is as follows:

[0008] A flexible robot joint electromagnetic drive, comprising a stator module, a flexible connection mechanism and a swing module:

[0009] The stator module comprises a base and an electromagnetic coil fixed on the base;

[0010] The flexible connection mechanism is connected to the stator module at one end and connected to the swing module at the other end, and the flexible connection mechanism is a polypropylene imine film, a polyvinyl chloride plate or a spring steel sheet;

[0011] 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 to the execution unit.

[0012] In order to solve the core problems of the lack of joint compliance caused by the dependence of traditional motor on rigid transmission and the insufficient driving power density of artificial muscle in the existing bionic drive technology. The electromagnetic drive and the flexible connection mechanism are integrated in the present application, which not only has a high energy density driving level similar to the motor, but also has compliance, and can realize the performance close to biological joints (innovatively combining the high energy density characteristics of electromagnetic drive and the passive compliance characteristics of biological tissue, breaking through the performance trade-off bottleneck of "drive force-compliance", realizing high-efficiency adaptive movement close to biological joints); effectively solving the inherent contradiction between traditional motor rigid transmission and artificial muscle driving power deficiency, providing a joint solution for bionic robots with high-efficiency drive and environmental adaptability.

[0013] The working principle of the flexible robot joint electromagnetic driver provided by the application is that the function of the flexible connecting mechanism is similar to that of a joint in a biological limb joint; an electromagnetic coil is installed in the stator module, and the passage of forward and reverse currents in the coil generates a forward and reverse magnetic field inside the coil; the swing module has a permanent magnet, and the structure design causes the permanent magnet to be arranged in the electromagnetic coil of the stator module; when the magnetic field in the electromagnetic coil changes, the permanent magnet causes the swing module to swing in response to the stator magnetic field, thereby generating a swing movement, which drives the execution unit to complete a corresponding action.

[0014] The base is prepared by a silicon steel sheet stacking process, and the electromagnetic coil is a copper coil. The base prepared by the silicon steel sheet stacking process helps to improve the magnetic permeability and reduce the iron loss; the electromagnetic coil group is composed of two groups of precisely wound copper coils, and the diameter of the copper wire, the inner diameter, the outer diameter and the height of the coil can be adjusted according to different loads.

[0015] Further, the electromagnetic coil includes two groups of electromagnetic coils, which are fixed in the preset groove of the base by an adhesive. For example, the two groups of electromagnetic coils can be fixed in the preset groove of the base by an epoxy adhesive.

[0016] Further, the stator module includes a damping ring.

[0017] By providing a damping ring that can be installed as needed in the stator module, the damping ring can resist the rebound of the execution unit in the application scenario of the mechanical finger, so that the execution unit can have a certain resistance when driven without current, to maintain the current position; in the application scenarios of the bionic fish fin and the bionic bird wing, the damping ring can be omitted to ensure the demand for high-frequency swing.

[0018] The thickness of the flexible substrate can be adjusted according to the load.

[0019] Further, the flexible connecting mechanism is selected from a spring steel sheet with a thickness of 0.1 mm, a polypropylene imine film with a thickness of 0.3 mm, or a polyvinyl chloride plate with a thickness of 0.2 mm.

[0020] Further, the swing module includes two neodymium iron boron spherical permanent magnets, which are fixed in the positioning cavity of the force transmission unit. The surfaces of the two neodymium iron boron spherical permanent magnets are nickel-plated.

[0021] The execution unit is a flexible robotic fish tail fin, a bionic bird wing or a bionic mechanical finger.

[0022] The flexible connecting mechanism is connected to the base in the stator module and the force transmission unit in the swing module by an adhesive, and the force transmission unit and the execution unit in the swing module are connected by a screw or an adhesive. A micro stainless steel positioning pin is used to enhance the mechanical stability.

[0023] The advantages of the present application compared with the prior art are:

[0024] The electromagnetic drive and flexible connection mechanism are integrated, high energy density drive is achieved by optimizing the magnetic circuit structure, and the flexible connection mechanism gives the joint passive compliance characteristics, effectively buffers the impact and adapts to complex motion requirements, breaking through the performance contradiction of traditional rigid transmission and artificial muscle scheme; the device adopts a modular structure, the modular structure supports flexible configuration of the damping ring, which can meet the static position keeping requirements of bionic mechanical fingers and other scenes, and can also realize high-frequency swinging of bionic fins, and different dynamic characteristics are adjusted and adapted through the core component, which significantly expands the application scene adaptability; the row unit is adapted to various bionic components through a detachable interface, and the customization design of the substrate material and the coil parameters meets different load requirements. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 A flexible joint electromagnetic drive structure diagram is provided for example 1 taking a bionic fin as an example;

[0026] Figure 2 A flexible joint electromagnetic drive structure composition diagram is provided for example 1 taking a bionic fin as an example;

[0027] Figure 3 A working principle diagram of a flexible joint electromagnetic drive is provided for example 1 taking a bionic fin as an example;

[0028] Figure 4 A flexible joint electromagnetic drive structure diagram is provided for example 2 taking a bionic bird wing as an example;

[0029] Figure 5 A flexible joint electromagnetic drive structure diagram is provided for example 3 taking a bionic finger as an example;

[0030] Figure 6 A flexible joint electromagnetic drive structure composition diagram is provided for example 3 taking a bionic finger as an example. DETAILED DESCRIPTION

[0031] The invention content of the present application will be further described below in combination with the drawings and examples.

[0032] Example 1: Flexible joint electromagnetic drive taking bionic fin as an example

[0033] As shown in Figure 1 and Figure 2 , the embodiment provided specifically includes a stator module 1, a flexible connection mechanism 2 and a swinging module 3:

[0034] The stator module 1 comprises a base 4 and an electromagnetic coil 5: the base 4 is made by the process of silicon steel sheet stacking, and the electromagnetic coil 5 is composed of two groups of precision wound copper coils, and the electromagnetic coil 5 is fixed in the preset slot of the base 4 by epoxy resin adhesive;

[0035] The flexible connecting mechanism 2 is a 0.3mm-thick polypropylene imine film 6, and the material is selected according to the load of the execution unit; one end of the flexible substrate 6 is connected to the base 4 in the stator module 1 by strong glue, and the other end is also bonded to the force transmission unit 8 in the swing module 3 by strong glue, and a micro stainless steel positioning pin is additionally used to enhance the mechanical stability.

[0036] The swing module 3 comprises two neodymium-iron-boron spherical permanent magnets 7, a force transmission unit 8 and an execution unit: the permanent magnets are surface plated with nickel and fixed in the positioning cavity of the aluminum alloy force transmission unit 8 by adhesive; the force transmission unit 8 and the execution unit can be connected by screws or by adhesive.

[0037] In the embodiment, the execution unit is a flexible robotic fish tail fin 9.

[0038] As shown in Figure 3 , the working process of the flexible joint electromagnetic driver taking the bionic fish fin as an example provided by the embodiment is as follows:

[0039] Place the bionic fish fin in water, and apply a sinusoidal varying current to the electromagnetic coil, and the amplitude and frequency of the current are controllable. At this time, a varying magnetic field will be generated in the coil, and 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, so that the magnetic field of the spherical permanent magnet is aligned from the Dir-M direction to the Dir-S direction, thereby generating an electromagnetic torque. Therefore, applying sinusoidal clockwise and counterclockwise currents to the coil will induce periodic changes in the electromagnetic torque, thereby driving the oscillation of the spherical permanent magnet. The oscillation of the spherical permanent magnet will drive the bionic fish fin to move, and the bionic fish fin will generate a forward propulsion force in the water, thereby driving the robotic fish to swim.

[0040] Embodiment 2: Flexible joint electromagnetic driver taking bionic bird wings as an example

[0041] The difference from embodiment 1 is that, as shown in Figure 4 , the execution unit of the embodiment is a bionic bird wing 10. The material of the flexible substrate 6 is a 0.2mm-thick polyvinyl chloride plate.

[0042] Embodiment 3: Flexible joint electromagnetic driver taking bionic mechanical finger as an example

[0043] The difference from embodiment 1 is that, as shown in Figure 5As shown, the execution unit of the present embodiment is a bionic mechanical finger 11, and the stator module 1 has a damping ring 12 (as shown) that can be installed according to requirements Figure 6 As shown, the damping ring can resist the rebound of the execution unit in the mechanical finger application scenario, so that the execution unit can have a certain resistance when driven without current, to maintain the current position.

Claims

1. A flexible robotic joint electromagnetic drive, characterized by, 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 two groups of electromagnetic coils fixed on the base; the stator module comprises a damping ring; The flexible connecting mechanism is connected with the stator module at one end and connected with the swing module at the other end, and the flexible connecting mechanism is a polyacrylimine film, a polyvinyl chloride plate or a spring steel sheet; The swing module comprises two Nd-Fe-B spherical permanent magnets corresponding to the electromagnetic coils, a force transmission unit and an execution unit, the permanent magnets are fixed in the positioning cavity of the force transmission unit, and the force transmission unit is connected with the execution unit.

2. The flexible robotic joint electromagnetic drive of claim 1, wherein, The base is prepared by a silicon steel sheet stacking process, and the electromagnetic coils are copper coils.

3. The flexible robotic joint electromagnetic drive of claim 1, wherein, The two groups of electromagnetic coils are fixed in the preset groove of the base by an adhesive.

4. The flexible robotic joint electromagnetic drive of claim 1, wherein, The flexible connecting mechanism is selected from a spring steel sheet with a thickness of 0.1 mm, a polyacrylimine film with a thickness of 0.3 mm or a polyvinyl chloride plate with a thickness of 0.2 mm.

5. The flexible robotic joint electromagnetic drive of claim 1, wherein, The execution unit is a flexible robot fish tail fin, a bionic bird wing or a bionic mechanical finger.

6. The flexible robotic joint electromagnetic drive of claim 1, wherein, The flexible connecting mechanism is connected with the base in the stator module and the force transmission unit in the swing module by an adhesive, and the force transmission unit and the execution unit in the swing module are connected by a screw or an adhesive.

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