Foot end of foot type mobile robot suitable for non-structural terrain and walking method

Abstract

The invention belongs to the field of mobile robots, and particularly relates to a foot-type mobile robot foot end suitable for non-structural terrains and a walking method, and the foot-type mobile robot foot end comprises a foundation plate, a spherical hinge module and an elastic air bag group; the spherical hinge module comprises a spherical hinge seat connected to the leg of the mobile robot, a spherical hinge head integrally connected with the spherical hinge seat and a spherical pair for installing the spherical hinge head, and the spherical pair is connected into a middle through hole of the foundation plate through a spherical pair fixing plate; the force sensor installed on the spherical pair fixing plate is used for measuring the load borne by the spherical hinge module. The elastic air bag set comprises a plurality of elastic air bags, the elastic air bags are arranged and installed at the bottom of the foundation plate through the elastic air bag fixing modules in the walking direction, the foot pulling device can adapt to different working conditions and different terrains, and the adsorption resistance of soft soil to the foot end in the foot pulling process is effectively reduced.

Description

Technical Field

[0001] The invention relates to the field of mobile robots, and in particular to a foot end of a foot-type mobile robot suitable for unstructured terrain and a walking method. Background Art

[0002] The mobile mechanisms of mobile robots mainly include wheeled mobile mechanisms, tracked mobile mechanisms and footed mobile mechanisms. In addition, there are stepping mobile mechanisms, creeping mobile mechanisms, serpentine mobile mechanisms and hybrid mobile mechanisms to adapt to different working environments and occasions. Generally, indoor mobile robots usually use wheeled mobile mechanisms, while outdoor mobile robots mostly use tracked mobile mechanisms to adapt to the needs of the field environment. Some bionic robots usually imitate a certain biological movement mode and use corresponding mobile mechanisms, such as the robot snake using a serpentine mobile mechanism and the robot fish using a tail fin propulsion mobile mechanism. Among them, the wheeled type has the highest efficiency, but the adaptability is relatively poor.

[0003] The legged robot has strong terrain adaptability, and its motion trajectory consists of a series of discrete points. Rough terrain can provide support for these discrete points, allowing the robot to move smoothly. The motion of wheeled and tracked robots is a continuous trajectory. Some terrains with large undulations do not support this continuous motion trajectory, which in turn limits the range of activities of this type of robot. The legs of the legged robot have multiple degrees of freedom, and the movement is more flexible. The center of gravity of the robot can be controlled by adjusting the length of the legs, so it is not easy to overturn and has higher stability. The body of the legged robot is separated from the ground. The advantage of this mechanical structure is that the robot body can move smoothly without considering the roughness of the ground and the position of the legs. It is characterized by good stability and strong off-road ability. However, this type of robot moves slowly and has poor maneuverability. Therefore, the load of the robot cannot be too heavy; the adaptability of the footed robot to the ground and the flexibility of movement need to be further improved; the control system of the footed robot is relatively complex, and the control method needs to be improved.

[0004] At present, the support methods of non-structural soft terrain walking machinery are usually foot-type or crawler-type support, but both support methods cannot provide reliable support for machinery on soft ground such as coastal mudflats, which are mixed with rocks, sand, and mud and accompanied by seawater scouring. Crawler-type support overcomes the problems of sinking and being compressed, and has a certain degree of adaptive ability, but on soft ground, the adhesion between the crawler and the soft ground is often less than the total resistance of the crawler-type walking machinery, resulting in the inability of underwater walking machinery to move. Foot-type support is usually a flat plate structure. Due to the limitations of the mechanical structure, the ground contact area is small and the ground contact pressure is large. Therefore, there will be a certain amount of sinking on soft ground. In addition, under the pressure of seawater and mud, the support structure is easily compressed and cannot be lifted. In addition, the flat plate support structure is difficult to form a stable support on a terrain mixed with rocks, sand, and mud. In severe cases, it will cause the machinery to overturn. It does not have the ability to adapt to complex terrain. Summary of the invention

[0005] To solve the above problems, the present invention provides a foot-type mobile robot suitable for unstructured terrain, which can dynamically sense the changes in the load borne by the support and realize two different working modes through the combined load-bearing of steel structure and elastic airbag.

[0006] The present invention is achieved through the following technical solutions: A foot end of a foot-type mobile robot suitable for unstructured terrain, comprising a base plate 100, a ball joint module 300, and an elastic airbag group 400; the ball joint module 300 comprises a ball joint seat 330 connected to the leg of the mobile robot, a ball joint head 320 integrally connected to the ball joint seat 330, and a spherical pair 340 for mounting the ball joint head 320, the spherical pair 340 being connected to the middle through hole of the base plate 100 via a spherical pair fixing plate 350; a force sensor 310 mounted on the spherical pair fixing plate 350 is used to measure the load on the ball joint module 300; the elastic airbag group 400 comprises a plurality of elastic airbags, which are arranged and mounted at the bottom of the base plate 100 along the walking direction via an elastic airbag fixing module 500.

[0007] As a more optimal technical solution of the present invention: the base plate 100 includes a central plate 110, a side plate 120 and a steel structure beam 130 which are fixedly connected as one body, the central plate 110 and the side plate 120 have an angle of 45°, and the steel structure beam 130 is vertically and evenly arranged and installed below the central plate 110. The steel structure beam 130 is used to improve the overall strength of the base plate 100, assist in fixing the elastic airbag group 400, and improve the supporting rigidity.

[0008] As a better technical solution of the present invention: a transition inclined plate module 200 is installed on the base plate 100, and the transition inclined plate module 200 is a quadrangular pyramid, and the side surfaces are respectively a front steel plate 210, a rear steel plate 220, a left steel plate 230 and a right steel plate 240, the top surface is a center steel plate 250, and the bottom edge is connected to the upper surface of the base plate 100.

[0009] As a more optimal technical solution of the present invention: the elastic airbag group 400 includes a first elastic airbag 420, a first elastic airbag 430, a first elastic airbag 440 and a first elastic airbag 450, and a pressure sensor is installed inside the elastic airbag. The elastic airbag is made of a material that undergoes elastic deformation under force and is used for shock absorption and seismic isolation. When working in a non-structural soft terrain mixed with rock, mud and sand, the control system changes the internal pressure of the elastic airbag to adjust the stiffness of the elastic airbag. The elastic airbag is compressed and deformed to better fit the ground to adapt to different terrains. At the same time, the contact state between the elastic airbag and the ground changes with the load during the load-bearing process, which can effectively reduce the adsorption resistance of the soft soil to the foot end during the foot pulling process.

[0010] As a better technical solution of the present invention: the elastic airbag fixing module 500 includes a flexible mesh sleeve 510 and a lifting ear, the flexible mesh sleeve 510 is fixedly connected to the lower surface of the base plate 100 through the lifting ear, the lifting ear includes a lifting ear cover 520 and a lifting ear base 530 connected as one body, and the flexible mesh sleeve 510 is connected to the lifting ear through a connecting rope.

[0011] As a more optimal technical solution of the present invention: it also includes a control system 600, and the control system 600 is controlled and connected with the force sensor 310 and the inflation and deflation system of the elastic airbag group 400.

[0012] Another object of the present invention is to provide a walking method for a foot-end of a foot-type mobile robot suitable for unstructured terrain, including taking the foot-end load as an excitation, measuring the foot-end load through a force sensor 310, adjusting the pressure inside the elastic airbag according to the foot-end load, applying an initial pressure to the elastic airbag group 400, whose bearing pressure is P1, and taking the ball joint boundary force F1 as the load threshold, to meet two working modes: If the ball joint force is greater than F1, it is in a fixed working mode. At this time, the control system 600 opens the air valve of the elastic airbag and starts the air pump to inflate the elastic airbag group 400 to increase the internal pressure of the elastic airbag to generate a supporting force greater than P1; If the ball joint force is less than F1, it is in the recovery working mode. When the elastic airbag pressure is less than the initial pressure, the control system 600 maintains the elastic airbag pressure unchanged. When the elastic airbag pressure is greater than the initial pressure, the control system 600 opens the elastic airbag valve to reduce the internal pressure of the elastic airbag until the initial pressure is reached and the system closes the elastic airbag valve.

[0013] The beneficial effects of the present invention are: The present invention monitors the load of the ball joint module in real time, and the control system adjusts the internal pressure of the elastic airbag according to the load to change the elastic airbag stiffness and adjust the contact area between the elastic airbag and the ground to meet different working conditions. The supporting contact surface is composed of the bottom surface of the base plate and four supporting surfaces formed by the pressure of four elastic airbags. The deformation of the elastic airbag can increase the contact area with the non-structural ground, so that the foot end of the present invention has good terrain adaptive ability. At the same time, the contact state between the deformable elastic airbag and the ground changes with the load during the load-bearing process, which can effectively reduce the adsorption resistance of the soft soil to the foot end during the foot pulling process. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the foot end structure of the non-structured soft terrain walking support of the present invention; Figure 2 It is a schematic diagram of the structure of the base plate for supporting the foot end of walking on non-structured soft terrain according to the present invention; Figure 3It is a schematic diagram of the transition inclined plate structure of the foot end of the non-structured soft terrain walking support of the present invention; Figure 4 It is a schematic diagram of the structure of the ball joint head of the foot end of the non-structured soft terrain walking support of the present invention; Figure 5 It is a schematic structural diagram of a ball joint seat module of the foot end of the non-structural soft terrain walking support of the present invention; Figure 6 It is a schematic diagram of the force sensor connection structure of the foot end of the non-structured soft terrain walking support of the present invention; Figure 7 It is a schematic diagram of the structure of the elastic air bag group of the foot end of the non-structured soft terrain walking support of the present invention; Figure 8 This is a schematic diagram of the mesh structure of the foot end of the non-structured soft terrain walking support of the present invention Fig. 9 This is a schematic diagram of the lug structure of the foot end of the non-structured soft terrain walking support of the present invention Fig.10 Flow chart of the foot end control method for walking support on unstructured soft terrain of the present invention; Among them, the base plate 100: a central plate 110, a side plate 120, and a steel structure beam 130; the transition inclined plate 200: a front steel plate 210, a rear steel plate 220, a left steel plate 230, a right steel plate 240 and a central steel plate 250; the ball joint module 300: a force sensor 310, a ball joint head 320, a ball joint seat 330, a spherical pair 340, and a spherical pair fixing plate 350; the elastic airbag group 400: a first elastic airbag 420, a first elastic airbag 430, a first elastic airbag 440, and a first elastic airbag 450; the elastic airbag fixing module 500: a flexible mesh sleeve 510, a lifting ear cover 520, and a lifting ear base 530; and a control system module 600. DETAILED DESCRIPTION

[0015] The present invention will be further described in detail below with reference to the accompanying drawings.

[0016] like Figure 1As shown, the present invention provides a foot end of a foot-type mobile robot suitable for unstructured terrain, including a base plate 100, a ball joint module 300, and an elastic airbag group 400; the ball joint module 300 includes a ball joint seat 330 connected to the leg of the mobile robot, a ball joint head 320 integrally connected to the ball joint seat 330, and a spherical pair 340 for installing the ball joint head 320, and the spherical pair 340 is connected to the middle through hole of the base plate 100 through a spherical pair fixing plate 350; the force sensor 310 installed on the spherical pair fixing plate 350 is used to measure the load on the ball joint module 300, and feed back the data to the control system 600, thereby determining the working condition of the new support; the spherical pair has three rotational degrees of freedom in space, allowing the foot end to obtain a swing angle of more than 10° in three directions, the installation plane of the ball joint module 300 is lower than the surface of the foot end, and is built into the transition slope of the foot end to reduce the influence of soil particles on the movement of the ball joint. The elastic airbag group 400 includes a plurality of elastic airbags, which are arranged and installed at the bottom of the base plate 100 along the walking direction through the elastic airbag fixing module 500. A control system 600 is also included, and the control system 600 is connected to the force sensor 310 and the inflation and deflation system of the elastic airbag group 400.

[0017] In some embodiments, Figure 2 As shown, the base plate 100 of the present invention includes a center plate 110, a side plate 120 and a steel structure beam 130. The angle between the center plate 110 and the side plate 120 is 45°, and the steel structure beam 130 is vertically and evenly installed below the center plate 110. The steel structure beam 130 is used to improve the overall strength of the base plate 100, assist in fixing the elastic airbag group 400, and improve the support rigidity. The side plate 120 is provided with a circular hole for balancing the pressure. The structure of the base plate 100 is helpful for sand fixation and can prevent the support surface from collapsing and causing support failure.

[0018] In some embodiments, Figure 3 As shown, a transition inclined plate module 200 is installed on the base plate 100 of the present invention. The transition inclined plate module 200 is a quadrangular pyramid, and the sides are respectively a front steel plate 210, a rear steel plate 220, a left steel plate 230 and a right steel plate 240, and the top surface is a central steel plate 250, and the bottom edge is connected to the upper surface of the base plate 100. The central steel plate 250 is rectangular, and the front steel plate 210, the rear steel plate 220, the left steel plate 230, and the right steel plate 240 are all trapezoidal, forming an inclined plane with an angle of 35° with the central steel plate 250, which can effectively prevent sediment accumulation.

[0019] In some embodiments, Figure 7As shown, the elastic airbag group 400 described in the present invention includes a first elastic airbag 420, a first elastic airbag 430, a first elastic airbag 440 and a first elastic airbag 450, and a pressure sensor is installed inside the elastic airbag. The elastic airbag is made of a material that undergoes elastic deformation when subjected to force, and is used for shock absorption and seismic isolation. When working in a non-structural soft terrain mixed with rock, mud and sand, the control system changes the internal pressure of the elastic airbag to adjust the stiffness of the elastic airbag. The elastic airbag is compressed and deformed to better fit the ground to adapt to different terrains. At the same time, the contact state between the elastic airbag and the ground changes with the load during the load-bearing process, which can effectively reduce the adsorption resistance of the soft soil to the foot end during the foot pulling process.

[0020] In some embodiments, Figure 8 and 9 As shown, the elastic airbag fixing module 500 described in the present invention includes a flexible mesh sleeve 510 and a lifting ear. The flexible mesh sleeve 510 is fixedly connected to the lower surface of the base plate 100 through the lifting ear. The lifting ear includes a lifting ear cover 520 and a lifting ear base 530 connected as one body. The flexible mesh sleeve 510 is connected to the lifting ear through a connecting rope.

[0021] In some embodiments, Fig.10 As shown, the present invention also provides a walking method for the foot of a foot-type mobile robot suitable for unstructured terrain. Based on the above foot implementation, the initial pressure of the elastic airbag group 400 is set to 5MPa and the bearing pressure is P1 in the unloaded state of the foot. When the foot is switched to a fixed working mode, the force sensor 310 installed at the bottom of the ball joint module 300 collects the foot load and feeds it back to the control system for comparison with the ball joint boundary force F1. If the foot load is greater than the ball joint boundary force F1, the control system 600 opens the air valve of the elastic airbag and starts the air pump to inflate the elastic airbag group 400, increase the internal pressure of the elastic airbag, and generate a support force greater than P1. When the foot end switches to the recovery working mode, the force sensor 310 collects the foot end load and feeds it back to the control system for comparison with the ball joint boundary force F1. If the foot end load is less than the ball joint boundary force F1, the control system detects the elastic airbag pressure. When the elastic airbag pressure is less than 5MPa, the control system maintains the elastic airbag pressure unchanged. When the elastic airbag pressure is greater than 5MPa, the control system opens the elastic airbag valve and slowly reduces the internal pressure of the elastic airbag until it reaches 5MPa. The system then closes the elastic airbag valve.

[0022] In the description of the present invention, it is necessary to understand that the terms "center", "vertical", "up", "down", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0023] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0025] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A foot-end of a foot-type mobile robot suitable for unstructured terrain, characterized in that: It includes a base plate, a ball joint module, and an elastic airbag group; the ball joint module includes a ball joint seat connected to the leg of the mobile robot, a ball joint head integrally connected to the ball joint seat, and a spherical pair for installing the ball joint head, and the spherical pair is connected to the middle through hole of the base plate through a spherical pair fixing plate; the force sensor installed on the spherical pair fixing plate is used to measure the load on the ball joint module; the elastic airbag group includes a plurality of elastic airbags, and the elastic airbags are arranged and installed at the bottom of the base plate along the walking direction through the elastic airbag fixing module; The walking method of the foot end of the foot-type mobile robot includes taking the foot end load as an excitation, measuring the foot end load through a force sensor, adjusting the pressure inside the elastic airbag according to the foot end load, applying an initial pressure to the elastic airbag group, and its bearing pressure is P1, and taking the ball joint boundary force F1 as the load threshold, which is used to meet two working modes: if the ball joint force is greater than F1, it is in a fixed working mode, at this time the control system opens the air valve of the elastic airbag, and starts the air pump to inflate the elastic airbag group to increase the internal pressure of the elastic airbag to generate a supporting force greater than P1; if the ball joint force is less than F1, it is in a recovery working mode, when the elastic airbag pressure is less than the initial pressure, the control system maintains the elastic airbag pressure unchanged, and when the elastic airbag pressure is greater than the initial pressure, the control system opens the elastic airbag valve to reduce the internal pressure of the elastic airbag until the system closes the elastic airbag valve when the initial pressure is reached.

2. The foot end of the foot-type mobile robot suitable for unstructured terrain according to claim 1, characterized in that: The base plate comprises a central plate, side plates and a steel structure beam which are fixedly connected as one body. The angle between the central plate and the side plates is an acute angle. The steel structure beams are vertically and evenly arranged and installed below the central plate.

3. The foot end of the foot-type mobile robot suitable for unstructured terrain according to claim 1, characterized in that: A transition inclined plate module is installed on the base plate. The transition inclined plate module is a four-sided platform used to prevent mud and sand from accumulating on the foot end surface. The side surfaces are the front steel plate, the rear steel plate, the left steel plate and the right steel plate, the top surface is the center steel plate, and the bottom edge is connected to the upper surface of the base plate.

4. The foot end of the foot-type mobile robot suitable for unstructured terrain according to claim 1, characterized in that: The elastic airbag group includes four elastic airbags, including a first elastic airbag, a first elastic airbag, a first elastic airbag and a first elastic airbag.

5. The foot end of the foot-type mobile robot suitable for unstructured terrain according to claim 1, characterized in that: A pressure sensor is installed inside the elastic airbag.

6. The foot end of the foot-type mobile robot suitable for unstructured terrain according to claim 1, characterized in that: The elastic airbag fixing module comprises a flexible mesh sleeve and a lifting ear, and the flexible mesh sleeve is fixedly connected to the lower surface of the base plate through the lifting ear.

7. The foot end of the foot-type mobile robot suitable for unstructured terrain according to claim 1, characterized in that: The lifting ear comprises a lifting ear upper cover and a lifting ear base which are connected as one body, and the flexible net sleeve is connected to the lifting ear through a connecting rope.

8. The foot end of the foot-type mobile robot suitable for unstructured terrain according to claim 1, characterized in that: It also includes a control system, which is controlled and connected with the force sensor, the inflation and deflation system of the elastic airbag group and the pressure sensor.

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