Ground feel variable damping cushioning foot device

Abstract

The application discloses a touch ground sensing variable damping buffer foot device, which comprises a main body support and a flexible foot bottom, both ends of the main body support are respectively provided with a sliding way, a sliding block component is slidably arranged in each sliding way, and the top of the sliding way is fixedly connected with a spring cover; the sliding block component comprises an outer sliding block, the outer sliding block is slidably sleeved in the sliding way, the upper outer wall of the outer sliding block is in contact with the inner wall of the sliding way, and an excitation coil and a magnetorheological fluid are arranged on the outer wall in contact with the outer sliding block in a circumferential direction; a through hole is formed in the outer sliding block in an axial direction, an inner sliding block, a magnet and an inner spring are sequentially and slidably arranged in the through hole from bottom to top, the bottom of the inner sliding block extends out of the outer sliding block, an insulating cover outside the through hole is fixedly connected with the upper surface of the outer sliding block, a detection coil is arranged on the upper portion of the insulating cover, and the detection coil is in contact with the top of the inner spring; the flexible foot bottom is arranged at the bottom of the main body support; and the application realizes the fusion of the detection of the touch ground signal and the buffer structure by using a double stroke structure.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of biped humanoid robots, in particular to a touch ground sensing variable damping buffer foot device. BACKGROUND

[0002] Humanoid robot is an intelligent robot with human shape, such as double hands, double feet, trunk and head features, etc. It is also the specific form of the robot in people's imagination. It can realize human-like walking action, use human tools, and has strong adaptability to unknown environment, greatly reducing the cost of special robot to the environment modification, and replacing manual labor to complete more complex work tasks. Humanoid robot is a comprehensive application platform system integrating multiple basic disciplines, cooperating with bionics, control theory and artificial intelligence, etc. High-level innovative and intensive mechatronics platform can evaluate the level of national science and technology development. In recent years, the research of humanoid robot in structure, driving and control relies more on the basic theory of human bionics, while the research of humanoid robot also shows the general law of human motion, which promotes each other and has extremely important role in serving special groups and improving human living standard. Therefore, humanoid robot has important research significance and application value.

[0003] In the early stage, the motion control of humanoid robot is to realize quasi-static walking by using off-line trajectory planning and on-line stable adjustment, that is, the center of pressure of the robot is in the support plane (the support polygon area formed by the support foot) at each time. The switching of the support leg and the swing leg in such motion trajectory is set in advance, so the robustness is not strong and the motion speed is not fast. In order to realize high-speed and strong-stability motion, the control of humanoid robot must consider high dynamic motion, and the judgment of the contact state between the foot and the ground is particularly important at this time.

[0004] In the process of dynamic walking of humanoid robot, the contact state between the double legs and the ground needs to be detected in real time, so as to control the motion planning of the next period according to the current robot state parameters. For example, when the robot leg swings in the air, the foot has no contact with the ground. When it is detected that the end of the foot contacts with the ground, the algorithm will make the swing leg execute the specific trajectory of the support leg function, and the support leg at the last time becomes the swing leg at this time. Therefore, the contact detection of the swing leg determines the execution of the robot motion decision algorithm.

[0005] In the implementation of the foot contact detection method, it can be mainly divided into two kinds based on multi-dimensional force sensor or based on bottom switch. For example, Chinese invention patent CN201780029305.7 provides a contact detection device, which is composed of a base material formed into a specific shape and a foamed synthetic resin body cut into a specific shape by foamed synthetic resin. A volume space is formed on one side or both sides between the base material and the foamed synthetic resin body. The air change in the volume space is detected by a sensor called air flow sensor, which applies external force to a specific surface. It is particularly related to two-dimensional and three-dimensional contact detection devices; but the configuration is complex, and more complex sensor detection is required, involving additional circuit design. In the international journal paper "Dynamic Locomotion For Passive-Ankle Biped Robots And Humanoids Using Whole-Body Locomotion Control" (DOI:10.1177 / ToBeAssigned), the author designed a special-shaped switch for the robot to realize contact detection, which can realize a larger range of contact detection, but it limits the shape of the foot and may not contact with the swing of the supporting leg, so the use range is limited. In the foreign doctoral thesis "Exploiting Inherent Robustness and Natural Dynamics in the Control of Bipedal Walking Robots", the foot design of the robot introduces more complex mechanical structure; in the doctoral thesis "Humanoid Robot Dynamic Synchronization via Whole-Body Teleoperation with Bilateral Feedback", the contact detection device for the point-foot robot is designed, which uses a rubber hemisphere outside the four one-dimensional force sensor array for protection. The design of the circuit and the processing of the sensor data in the program increases the complexity of the device.

[0006] However, the main disadvantages of the prior art are: most of them are in the form of sensors and circuits, which are expensive; the integration of the sensor is low, which cannot be used with the buffer; it cannot be perceived in advance before collision; the buffer parameters cannot be controlled, etc. SUMMARY

[0007] In order to solve the problems in the prior art, the application provides a touch sensing variable damping buffer foot device, which realizes the fusion of touch signal detection and buffer structure by using a double stroke structure; the first stroke is detected by using the Faraday effect, the second stroke is buffered by a large spring, and the damping force is adjusted by using the magnetorheological effect, and the double stroke mechanism is arranged on the forefoot and the hind foot to integrate the touch detection and the buffer of the entire foot bottom.

[0008] The technical scheme adopted by the application is as follows:

[0009] The touch sensing variable damping buffer foot device comprises:

[0010] A main support is used for being connected with an ankle joint of a humanoid robot; two ends of the main support are respectively provided with a slide, and each slide is slidably provided with a sliding block; a top of the slide is fixedly connected with a spring cover; the sliding block comprises an outer sliding block, the outer sliding block is slidably sleeved in the slide, an upper outer wall of the outer sliding block is in contact with an inner wall of the slide, and an excitation coil and magnetorheological fluid are arranged on the outer wall in contact with the outer sliding block in a circumferential direction; a through hole is formed in the outer sliding block in an axial direction, and an inner sliding block, a magnet and an inner spring are slidably arranged in the through hole from bottom to top; a bottom of the inner sliding block extends out of the outer sliding block, an insulating cover is arranged outside the through hole and is fixedly connected with an upper surface of the outer sliding block, a detection coil is arranged on the insulating cover, and the detection coil is in contact with a top of the inner spring; the detection coil and the excitation coil are signal-connected with a control unit.

[0011] A flexible foot bottom is arranged at a bottom of the main support, and a sliding block mounting groove is arranged at a position opposite to the slide of the flexible foot bottom; the sliding block mounting groove protrudes outward, and a bottom of the inner sliding block and a bottom of the outer sliding block are in contact with the sliding block mounting groove from bottom to top.

[0012] Further, three annular grooves are arranged in a circumferential direction at a position where the sliding block is in contact with an inner wall of the slide bottom, the middle annular groove is filled with the excitation coil and the magnetorheological fluid, and the two side annular grooves are respectively filled with sealing rings.

[0013] Further, the sealing ring is made of nitrile rubber.

[0014] Further, the outer spring has a greater rigidity than the inner spring.

[0015] Further, the flexible foot bottom is made of rubber material, and the bottom is further provided with anti-skid textures.

[0016] Further, the top of the main support is provided with an outer shell, and the outer shell is made of hard rubber or plastic material.

[0017] Further, the outer sliding block, the inner sliding block and the insulating cover are all made of insulating material.

[0018] Further, the main body support and the spring cover are both made of aluminum alloy material.

[0019] Further, the excitation coil is a multi-coil winding enameled wire, and a coil sleeve is arranged on the outer coil of the excitation coil.

[0020] Further, the detection coil is made of copper material.

[0021] The present application has the following beneficial effects:

[0022] (1) The touch sensing variable damping buffer foot device designed in the present application has two stages of travel, in the first stage of travel, the touch detection is performed through the Faraday effect, and in the second stage of travel, the damping force is adjusted through the magnetorheological effect to perform buffering and flexible support; therefore, the detection and buffering of the robot foot are organically combined.

[0023] (2) The biped structure arranged in front and back symmetry in the present application ensures a certain support while improving the flexible buffering capacity and touch detection performance of the foot.

[0024] (3) The touch sensing variable damping buffer foot device designed in the present application can overcome the problems of the traditional buffer device such as inflexible movement and insufficient compact structure. The device can detect the foot touch information before impact and has certain variable damping buffering performance, absorbs the impact force with the ground in the process of robot walking and running, and improves the perception and adaptation ability of the robot when moving in a complex environment. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is an exploded view of the touch sensing variable damping buffer foot device of the present application;

[0026] Figure 2 is a sectional view of the touch sensing variable damping buffer foot device of the present application;

[0027] Figure 3 is a structural schematic view of the main body support in the touch sensing variable damping buffer foot device of the present application;

[0028] Figure 4 is a structural schematic view of the slider component in the touch sensing variable damping buffer foot device of the present application;

[0029] Figure 5 in which a and b are both structural schematic views of the detection coil in the touch sensing variable damping buffer foot device of the present application;

[0030] Figure 6 is a structural schematic view of the flexible foot bottom in the touch sensing variable damping buffer foot device of the present application;

[0031] Figure 7is a schematic view of an inner sliding block structure in the ground-touching sensing variable-damping cushioning foot device of the present application;

[0032] In the figure, 1 is an outer shell, 2 is a spring cover, 3 is a sliding block component, 4 is a main body support, 5 is a flexible foot bottom, 6 is an ankle-foot fixing flange, 7 is a spring cover flange, 8 is a guide table, 9 is an outer shell mounting hole, 10 is a sliding channel, 11 is a guide groove, 3a is an outer spring, 3b is a detection coil, 3c is a sealing ring, 3d is a coil sleeve, 3e is an excitation coil, 3f is an insulating cover, 3g is an inner spring, 3h is a magnet, 3i is an outer sliding block, and 3j is an inner sliding block. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0034] The ground-touching sensing variable-damping cushioning foot device designed in the present application has a structure as shown in Figure 1 The ground-touching sensing variable-damping cushioning foot device designed in the present application has a structure as shown in

[0035] As shown in Figure 3 The two ends of the main body support 4 are respectively provided with one sliding channel 10, and each sliding channel 10 is provided with a group of sliding block components 3. The sliding block components 3 can move up and down along the axial direction in the sliding channel 10. More specifically, the sliding channel 10 is in a cylindrical shape, and the spring cover flange 7 is arranged on the top end face of the sliding channel 10 in the circumferential direction. The spring cover flange 7 is fixedly connected with the spring cover 2 through a screw, so that the spring cover 2 limits the sliding block components 3 in the corresponding sliding channel 10.

[0036] As shown in Figure 2 , 4, 5, 7, the slider component 3 includes inner slider 3j, outer slider 3i, magnet 3h, inner spring 3g, insulating cover 3f, excitation coil 3e, coil cover 3d, detection coil 3b, outer spring 3a; More specifically, the outer slider 3i middle position along the axial opening has a through hole, the through hole from bottom to top in turn is equipped with inner slider 3j, magnet 3h and inner spring 3g, and the through hole is provided with insulating cover 3f outside, and the insulating cover 3f is fixedly connected with the upper surface of the outer slider 3i by screws. The upper part of the insulating cover 3f is provided with a detection coil 3b, which can also be fixedly connected with the insulating cover 3f and the outer slider 3i by screws, and the detection coil 3b is in contact with the top of the inner spring 3g. The excitation coil 3e and the detection coil 3b are connected with the control unit through signal lines for transmission of monitoring signals and control signals.

[0037] The outer wall of the upper part of the slider component 3 is in contact with part of the inner wall of the slide 10, so that three annular grooves are arranged on the outer wall of the slider component 3, the middle annular groove is filled with excitation coil 3e and magnetorheological fluid, and the two side annular grooves are respectively filled with sealing rings 3c.

[0038] The outer spring 3a is arranged in the cavity between the outer slider 3i and the slide 10, i.e. the upper part of the detection coil 3b, the top of the outer spring 3a is in contact with the spring cover 2, and the stiffness of the outer spring 3a is greater than that of the inner spring 3g.

[0039] The flexible sole 5 is made of rubber material with good resilience and high wear resistance, which quickly deforms when the foot touches the ground and transmits the change to the inner slider component 3. The slider component mounting groove is provided at the position opposite to the slide 10, and the slider component mounting groove protrudes outward, the bottom of the inner slider 3j and the bottom of the outer slider 3i are in contact with the slider component mounting groove from bottom to top, which serves as the moving space of the slider component 3.

[0040] The middle part of the flexible sole 5 is provided with anti-skid texture.

[0041] In this embodiment, the materials of the inner spring 3g and the outer spring 3a are alloy steel springs, which can provide good elastic effect and high elastic life.

[0042] The outer slider 3i, the inner slider 3j and the insulating cover 3f are plastic insulating materials which need to have high mechanical strength and certain wear resistance, including but not limited to nylon, pom, ABS, etc.

[0043] The detection coil 3b is made of copper and is fixed on the insulating cover 3f by screws.

[0044] The sealing ring 3c is made of nitrile rubber.

[0045] The main body support 4 and the spring cover 2 are made of aluminum alloy material, which has good mechanical strength and magnetic shielding performance.

[0046] The excitation coil 3e is a multi-coil winding of enameled wire, and a coil cover 3d made of a conductive material is arranged on the outer coil of the excitation coil 3e to avoid coil abrasion.

[0047] The shell 1 is made of hard rubber or plastic material and is used for insulation, dustproof and waterproof.

[0048] The working process of the ground-touching sensing variable-damping cushioning foot device will be further described below:

[0049] When the foot just touches the ground, the flexible foot bottom 5 first pushes the inner sliding block 3j and the magnet 3h to move upward, and the inner spring 3g is first compressed; in this stage, the contact force is small, and the stiffness of the outer spring 3a is greater than that of the inner spring 3g, so the outer spring 3a is not compressed at this time. In this stage, when the magnet 3h moves upward with the inner sliding block 3j, the magnet 3h moves to generate a changing magnetic field, and the detection coil 3b detects the change of the magnetic field through the induced current to form a ground-touching detection signal.

[0050] With the continuous increase of the contact force, the inner sliding block 3j is compressed to the deepest position, and the bottom of the inner sliding block 3j is flush with the bottom of the outer sliding block 3i, at which time the bottom of the outer sliding block 3i becomes the main part in contact with the flexible foot bottom 5; with the continuous inward movement of the outer sliding block 3i, the outer spring 3a is compressed to form an impact force absorption, and at the same time, the excitation coil 3e located on the periphery of the outer sliding block 3i generates an excitation current through the controller, and the excitation coil 3e can form a radial magnetic field perpendicular to the inner cylindrical surface of the slide 10, so as to generate a magneto-rheological effect, that is, to make the coil cover 3d and the magneto-rheological fluid on the inner surface of the slide 10 yield, and then to control the yield strength, and further to control the damping force action of the coil cover 3d and the slide 10, so as to form a controllable impact absorption and dissipation capacity, thereby realizing the contact detection and impact buffering of the foot.

[0051] The above examples are only used to illustrate the design idea and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and to implement it, and the protection scope of the present application is not limited to the above examples. Therefore, any equivalent changes or modifications made according to the principles and design ideas disclosed by the present application are within the protection scope of the present application.

Claims

1. A ground-feel aware variable-damper cushion foot device characterized by, The utility model relates to a kind of flexible foot of robot, including: Main body support (4), the middle part of the main body support (4) is used to connect with the ankle joint of anthropomorphic robot;Two ends of the main body support (4) are respectively provided with 1 slide (10), each slide (10) is slidably equipped with slider component (3), and the top of the slide (10) is fixedly connected with spring cover (2);The slider component (3) includes outer slider (3i), the outer slider (3i) is slidably sleeved in slide (10), the upper outer wall of the outer slider (3i) is in contact with the inner wall of slide (10), and excitation coil (3e) and magnetorheological fluid are arranged on the outer wall at the contact of outer slider (3i) in the circumferential direction;A through hole is opened in the middle position of the outer slider (3i) in the axial direction, and the through hole is sequentially slidably equipped with inner slider (3j), magnet (3h) and inner spring (3g) from bottom to top, the bottom of the inner slider (3j) extends out of the outer slider (3i), an insulating cover (3f) is arranged outside the through hole, the insulating cover (3f) is fixedly connected with the upper surface of the outer slider (3i), a detection coil (3b) is arranged on the upper portion of the insulating cover (3f), and the detection coil (3b) is in contact with the top of the inner spring (3g);The detection coil (3b) and excitation coil (3e) are signal-connected to control unit;The upper portion of the detection coil (3b) is provided with outer spring (3a), and the top of the outer spring (3a) is in contact with spring cover (2); Flexible foot bottom (5) arranged at the bottom of the main body support (4), the flexible foot bottom (5) is provided with a slider component mounting groove opposite to the slide (10), the slider component mounting groove protrudes outward, the bottom of the inner slider (3j) and the bottom of the outer slider (3i) are sequentially in contact with the slider component mounting groove from bottom to top.

2. The ground-aware variable-damper cushion foot device of claim 1, wherein, The slider component (3) is provided with three annular grooves in contact with the inner wall of the bottom of the slide (10) in the circumferential direction, the middle annular groove is filled with excitation coil (3e) and magnetorheological fluid; The two side annular grooves are respectively filled with sealing ring (3c).

3. The ground-aware variable-damper cushion foot device of claim 2, wherein, The sealing ring (3c) is made of nitrile rubber.

4. The ground-aware variable-damper cushion foot device of claim 1, wherein, The stiffness of the outer spring (3a) is greater than that of the inner spring (3g).

5. The ground-aware variable-damper cushion foot device of claim 1, wherein, The flexible foot bottom (5) is made of rubber material, and the bottom is further provided with anti-skid texture.

6. The ground-aware variable-damper cushion foot device of claim 1, wherein, The top of the main body support (4) is provided with an outer shell (1), and the outer shell (1) is made of hard rubber or plastic material.

7. The ground-aware variable-damper cushion foot device of claim 1, wherein, The outer slider (3i), the inner slider (3j) and the insulating cover (3f) are all made of insulating material.

8. The ground-aware variable-damper cushion foot device of claim 1, wherein, The main body support (4) and the spring cover (2) are both made of aluminum alloy material.

9. The ground-aware variable-damper cushion foot device of claim 1, wherein, The excitation coil (3e) is a multi-coil winding enameled wire, and a coil sleeve (3d) is arranged on the outer coil of the excitation coil (3e).

10. The ground-aware variable-damper cushion foot device of claim 1, wherein, The detection coil (3b) is made of copper material.

Images