Four-footed robot dog structure with variable reduction ratio

Abstract

The invention discloses a four-footed robot dog structure with a variable reduction ratio. The four-footed robot dog structure comprises a supporting frame and leg structures fixed to the four corners of the supporting frame and composed of pitching motor assemblies, rolling motor assemblies, input transmission parts, thigh connecting rod parts, transmission connecting rod parts and shank connecting rod parts. According to the quadruped robot dog, through the transmission mode of the space four-bar mechanism with the unequal lengths, secondary speed reduction is conducted outside the motor, meanwhile, the load capacity of the quadruped robot dog is further improved, the movement performance of the quadruped robot dog on the mountain is improved, the requirement that the motor with the small torque transmits the large torque is met, and the service life of the quadruped robot dog is prolonged. The problem that the transmission torque of the foot structure of the quadruped robot dog is insufficient in the movement process is solved, and the movement performance of the quadruped robot dog is improved.

Description

Technical Field

[0001] This invention belongs to the field of quadruped robot dog design, and particularly relates to a quadruped robot dog structure with a variable reduction ratio. Background Technology

[0002] The quadruped robot dog is a high-tech integrated device that mimics the characteristics of a dog. It can jump, run, and crawl, and can be applied to scenarios such as future warfare, fire rescue, and mountain transport. The quadruped robot dog requires motors to provide power for its movement, thereby enabling various actions and functions.

[0003] Existing quadruped robot dog motor joint drives all have fixed reduction ratios, which can only work in the inefficient range. In order to meet the peak torque, they often need to be over-designed, which means that they cannot meet the requirement of a motor that can transmit a large torque with a small torque. In addition, there are problems such as difficulty in balancing high-speed swing and high torque support, low motion efficiency, and insufficient adaptability to complex terrain. Summary of the Invention

[0004] To address the issue of insufficient load capacity in existing quadruped robot dogs, this invention introduces an unequal-length spatial four-bar linkage, giving the quadruped robot dog's leg structure variable deceleration and increased torque characteristics, thereby improving the quadruped robot dog's load-bearing capacity.

[0005] The objective of this invention is achieved through the following technical solution: A quadruped robot dog structure with a variable reduction ratio includes a support frame and a leg structure fixed to the four corners of the support frame, consisting of a pitch motor assembly, a roll motor assembly, an input transmission component, a thigh linkage, a transmission linkage, and a lower leg linkage. The support frame includes a frame, and roll motor mounting holes and pitch motor mounting holes located at the four corners of the frame; The pitch motor assembly includes a connecting base at the bottom, a regular hexagonal short shaft and a cylindrical support shaft on both sides, and a first pitch motor and a second pitch motor located at the front and rear, respectively. The rolling motor assembly includes a rolling motor and a mounting plate fixed to the rolling motor, wherein the mounting plate has an internal hexagonal mounting hole in its center. The input transmission component includes a connector mounting hole at the bottom, a regular hexagonal boss at the top, and screw holes evenly distributed around the regular hexagonal boss in the circumference. The thigh linkage has a pitch motor mounting slot at the top and a lower leg connection hole at the bottom. The transmission linkage includes a main rod, and a first support rod and a second support rod located at both ends of the main rod; The lower leg connecting rod is provided with a connector mounting hole and a thigh connecting hole; The connecting base of the pitch motor assembly is fixedly connected to the pitch motor mounting slot at the top of the thigh linkage; the regular hexagonal short shaft of the pitch motor assembly is embedded in the internal hexagonal mounting hole of the roll motor assembly; the regular hexagonal boss of the input transmission component is embedded in the regular hexagonal mounting hole of the pitch motor assembly. The mounting plate of the roll motor assembly is fixedly installed in the roll motor mounting hole of the support frame; the cylindrical support shaft of the pitch motor assembly is installed in the pitch motor mounting hole through a spherical bearing; the second support rod of the transmission linkage is installed in the connector mounting hole of the input transmission component through a bearing; the lower leg connection hole of the thigh linkage is rotatably connected to the thigh connection hole of the lower leg linkage; the first support rod of the transmission linkage and the connector mounting hole of the lower leg linkage are rotatably connected through a bearing.

[0006] Furthermore, the center points of the hexagonal mounting holes of the pitch motor assembly, the connecting holes of the input transmission component, the thigh connecting holes of the lower leg linkage, and the connecting holes of the lower leg linkage are connected in sequence to form a spatial four-bar linkage with four sides of unequal length.

[0007] Furthermore, the included angle between the line connecting the center point of the regular hexagonal mounting hole and the center point of the calf connecting hole, and the line connecting the center point of the connector mounting hole and the center point of the regular hexagonal boss, is 35-145°. The distance between the center point of the regular hexagonal mounting hole and the center point of the lower leg connecting hole is less than the distance between the center point of the first support rod and the center point of the second support rod of the transmission connecting rod. The distance between the center point of the connecting hole of the input transmission component and the center point of the regular hexagonal boss is less than the distance between the center point of the thigh connecting hole of the lower leg connecting rod and the center point of the connecting hole.

[0008] Furthermore, the distance between the center point of the hexagonal mounting hole and the center point of the calf connecting hole is 350mm; The distance between the center point of the first support rod and the center point of the second support rod of the transmission linkage is 375mm. The distance between the center point of the connecting hole of the input transmission component and the center point of the regular hexagonal boss is 40mm. The distance between the center point of the thigh connection hole of the lower leg connecting member and the center point of the connecting member mounting hole is 65mm.

[0009] Furthermore, the reduction ratio of the spatial four-bar linkage is 0.4~0.8, and the rotation angle between the lower leg link and the upper leg link is 0~85°.

[0010] Furthermore, the axis of the output end of the pitch motor is perpendicular to and intersects the axis of the output end of the roll motor.

[0011] Furthermore, a through hole is formed at the center of the regular hexagonal boss of the input transmission component.

[0012] The beneficial effects of this invention are as follows: The quadruped robot dog of the present invention uses a spatial four-bar linkage with unequal lengths for transmission, which reduces the speed of the motor externally while further improving the load capacity of the quadruped robot dog and enhancing its uphill movement performance. That is, it can achieve the transmission of a large torque demand by a motor with a small torque; or, under the same load capacity, it can reduce the requirements of the motor and reduce the weight of the robot dog itself. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of a quadruped robot dog.

[0014] Figure 2 This is a schematic diagram of the rack.

[0015] Figure 3 This is a schematic diagram of a pitch motor.

[0016] Figure 4 This is a schematic diagram of a rolling motor.

[0017] Figure 5 This is a schematic diagram of the input transmission component.

[0018] Figure 6 Schematic diagram of the thigh linkage. Figure 7 This is a schematic diagram of a connecting rod.

[0019] Figure 8 This is a schematic diagram of the lower leg connecting rod.

[0020] Figure 9 for Figure 1 A magnified view of a portion of the image.

[0021] Figure 10 This is a schematic diagram of a spatial quadrilateral.

[0022] In the diagram, the components are: support frame 1, pitch motor 2, roll motor 3, input transmission component 4, thigh connecting rod 5, transmission connecting rod 6, lower leg connecting rod 7, roll motor mounting hole 101, pitch motor mounting hole 102, frame 103, connecting base 201, regular hexagonal mounting hole 202, regular hexagonal short shaft 203, cylindrical support shaft 204, first pitch motor 205, second pitch motor 206, fixing hole 207, internal hexagonal mounting hole 301, roll motor 302, mounting plate 303, connector mounting hole 401, screw hole 402, regular hexagonal boss 403, lower leg connecting hole 501, pitch motor mounting slot 502, main rod 602, first support rod 601, second support rod 603, connector mounting hole 701, and thigh connecting hole 702. Detailed Implementation

[0023] The present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. The purpose and effects of the present invention will become clearer. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0024] The quadruped robot dog structure of this invention features a variable reduction ratio. Utilizing the continuously changing transmission angle characteristic of a four-bar linkage during movement, the single-motor drive passively and automatically provides differentiated transmission ratios based on the leg movement phase (e.g., the "high-speed gear" during the swing phase and the "power gear" during the push-off phase), thereby optimizing output. This directly solves the problem of existing fixed-reduction-ratio joint motors often operating in inefficient zones and being over-designed to meet peak torque requirements, improving energy utilization efficiency and explosive power. Simultaneously, the structure itself can form a compact, multi-degree-of-freedom leg unit, enhancing the robot dog's mobility in narrow or unstructured terrain. The quadruped robot dog structure of this invention with a variable reduction ratio can also simplify traditional transmission chains, reduce leg inertia, and provide a certain degree of cushioning protection during impacts through the structural characteristics of the linkage mechanism.

[0025] like Figure 1 As shown in one embodiment, the quadruped robot dog structure is a sagittal plane symmetrical structure with two degrees of freedom: pitch and roll. Specifically, it includes a support frame 1 and a leg structure fixed to the four corners of the support frame 1, consisting of a pitch motor assembly 2, a roll motor assembly 3, an input transmission component 4, a thigh linkage 5, a transmission linkage 6, and a lower leg linkage 7.

[0026] like Figure 2 As shown, the support frame 1 includes a frame 103, and roll motor mounting holes 101 and pitch motor mounting holes 102 located at the four corners of the frame 103. The line connecting the center point of the roll motor mounting hole 101 and the center point of the pitch motor mounting hole 102 is parallel to the OX axis.

[0027] like Figure 3As shown, the pitch motor assembly 2 includes a connecting base 201, a hexagonal mounting hole 202, a hexagonal short shaft 203, a cylindrical support shaft 204, a first pitch motor 205, and a second pitch motor 206. The connecting base 201 is located at the bottom and is used to fix it to the pitch motor mounting slot 501 at the top of the thigh linkage 5, thereby connecting the entire pitch motor 2 to the thigh linkage 5. The hexagonal short shaft 203 and the cylindrical support shaft 204 are located on two side surfaces, respectively. The first pitch motor 205 and the second pitch motor 206 are located on the front and rear sides of the entire pitch motor assembly 2, respectively, and the hexagonal mounting hole 202 is located at the center of the first pitch motor 205.

[0028] like Figure 4 As shown, the rolling motor assembly 3 includes a rolling motor 302 and a mounting plate 303 fixed together with the rolling motor 302. The mounting plate 303 has an internal hexagonal mounting hole 301 in the center.

[0029] like Figure 5 As shown, the input transmission component 4 includes a connector mounting hole 401 at the bottom, a regular hexagonal boss 403 at the top, and screw holes 402 evenly distributed around the regular hexagonal boss 403. To reduce weight, a through hole is formed in the center of the regular hexagonal boss 403.

[0030] like Figure 6 As shown, the top of the thigh connecting rod 5 is provided with a pitch motor mounting groove 502, and the bottom is provided with a lower leg connecting hole 501.

[0031] like Figure 7 As shown, the transmission linkage 6 includes a main rod 602, and a first support rod 601 and a second support rod 603 located at both ends of the main rod 602.

[0032] like Figure 8 As shown, the lower leg connecting rod 7 has a connector mounting hole 701 and a thigh connecting hole 702.

[0033] like Figure 9 As shown, Figure 1 A magnified view of a section, from Figure 9 and Figure 3 As can be seen, the connecting base 201 of the pitch motor assembly 2 is fixed to the pitch motor mounting slot 502 on the top of the thigh linkage 5 by screws, thus connecting the pitch motor assembly 2 and the thigh linkage 5. The hexagonal short shaft 203 of the pitch motor assembly 2 is embedded in the internal hexagonal mounting hole 301 of the roll motor assembly 3, thus connecting the pitch motor assembly 2 and the roll motor assembly 3. The hexagonal boss 403 of the input transmission component 4 is embedded in the hexagonal mounting hole 202 of the pitch motor assembly 2, and a screw passes through the screw hole 402 and the fixing hole 207, thus achieving a straight-cut connection between the pitch motor assembly 2 and the input transmission component 4.

[0034] like Figure 9 As shown, the mounting plate 303 of the roll motor assembly 3 is fixedly installed in the roll motor mounting hole 101 of the support frame 1 with screws, realizing the fixed connection between the roll motor assembly 3 and the frame 1; the cylindrical support shaft 204 of the pitch motor assembly 2 is installed in the pitch motor mounting hole 102 through a spherical bearing, realizing the rotatable connection between the pitch motor assembly 2 and the support frame 1. The second support rod 603 of the transmission linkage 6 is installed in the connector mounting hole 401 of the input transmission component 4 through a fisheye bearing, realizing the connection between the transmission linkage 6 and the input transmission component 4.

[0035] like Figure 1 As shown, the thigh connecting hole 501 of the thigh connecting member 5 and the thigh connecting hole 702 of the thigh connecting member 7 are connected by a pin to realize the rotational connection between the thigh connecting member 5 and the thigh connecting member 7; the first support rod 601 of the transmission connecting member 6 and the connecting member mounting hole 701 of the thigh connecting member 7 are connected by a fisheye bearing to realize the rotational connection between the transmission connecting member 6 and the thigh connecting member 7.

[0036] like Figure 10 As shown, the lines connecting the center points of the hexagonal mounting hole 202 of the pitch motor assembly 2, the connecting hole 401 of the input transmission component 4, the thigh connecting hole 702 of the lower leg connecting rod 7, and the connecting hole 701 of the lower leg connecting rod 7 in sequence form an inverted quadrilateral on opposite sides of the frame. This is a spatial quadrilateral with unequal sides, which can be equivalent to a spatial four-bar linkage. Furthermore, the included angles between the lines connecting the center points of the hexagonal mounting hole 202 and the lower leg connecting hole 501, and between the center point of the connecting hole 401 and the center point of the hexagonal boss 403, are 35-145°. The distance between the center point of the hexagonal mounting hole 202 and the center point of the lower leg connecting hole 501 is less than the distance between the center point of the first support rod 601 and the center point of the second support rod 603 of the transmission link 6; the distance between the center point of the connecting hole 401 of the input transmission component 4 and the center point of the hexagonal boss 403 is less than the distance between the center point of the thigh connecting hole 702 of the lower leg link 7 and the center point of the connecting hole 701. This results in a variable reduction ratio of 0.4 to 0.8 for the unequal-length spatial four-bar linkage, and a rotation angle of 0 to 85° between the lower leg link 7 and the thigh link 5, which increases the torque by 1.25 to 2.5 times. This gives the leg structure of the quadruped robot dog variable reduction torque-increasing characteristics, improving the load-bearing capacity of the quadruped robot dog.

[0037] In this embodiment, the distance between the center point of the regular hexagonal mounting hole 202 and the center point of the calf connecting hole 501 is 350mm; The distance between the center point of the first support rod 601 and the center point of the second support rod 603 of the transmission link 6 is 375mm. The distance between the center point of the connecting hole 401 of the input transmission component 4 and the center point of the regular hexagonal boss 403 is 40mm. The distance between the center point of the thigh connection hole 702 of the lower leg connecting rod 7 and the center point of the connecting member mounting hole 701 is 65mm.

[0038] like Figure 1 As shown, the coordinate axes OXYZ are defined. The origin O is the center of the entire quadruped robot dog structure, i.e. the center of the support frame 1. The X-axis is the positive direction along the direction the robot dog moves forward, and the Z-axis is the positive direction perpendicular to the horizontal plane. The OX axis is rotated 90° counterclockwise along the OZ axis to form the OY direction.

[0039] In the initial position, the line connecting the center point of the pitch motor mounting hole 102 and the center point of the roll motor mounting hole 101 of the support frame 1 is parallel to the plane OXY in the coordinate system OXYZ of the support frame and parallel to the axis OX. That is, the axis of the roll motor's output end connected to the hexagonal mounting hole 301 coincides with the line connecting the center points of the pitch motor mounting hole 102 and the roll motor mounting hole 101 of the support frame 1. The roll motor's output end connected to the hexagonal mounting hole 301 provides the quadruped robot dog with rotational freedom around the OX axis. The axis of the pitch motor's output end connected to the regular hexagonal mounting hole 202 is parallel to the plane OXY in the coordinate system OXYZ of the support frame 1 and parallel to the axis OY. The pitch motor's output end connected to the regular hexagonal mounting hole 202 provides the quadruped robot dog with rotational freedom around the OY axis. Specifically, the axis of the pitch motor's output end is perpendicular to and intersects the axis of the roll motor's output end. Therefore, the pitch motor and the roll motor provide the quadruped robot dog with two degrees of freedom in space: pitch and roll. The roll motor provides the roll rotation of its own structural components for the pitch motor.

[0040] The second pitch motor 206 of the pitch motor assembly 2 determines the rotation angle of the first pitch motor 205, which in turn determines the swing of the thigh linkage 5; while the first pitch motor 205 determines the rotation of the input transmission component 4, which in turn determines the swing of the lower leg linkage 7. Therefore, the thigh swing of the quadruped robot dog is achieved through the second pitch motor 206, the connecting base 201, and the thigh linkage 5, and the lower leg swing of the quadruped robot dog is achieved through the first pitch motor 205, the input transmission component 4, the transmission linkage 6, and the lower leg linkage 7; that is, when the first pitch motor 205 and the coaxial second pitch motor 206 of the pitch motor assembly 2 rotate at different times, that is, when the four spatial four-bar linkages of unequal length form a variable reduction ratio transmission, the quadruped robot dog can crawl and jump.

[0041] It will be understood by those skilled in the art that the above descriptions are merely preferred examples of the invention and are not intended to limit the invention. Although the invention has been described in detail with reference to the foregoing examples, those skilled in the art can still modify the technical solutions described in the foregoing examples or make equivalent substitutions for some of the technical features. All modifications and equivalent substitutions made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A quadruped robot dog structure with a variable reduction ratio, characterized in that, It includes a support frame and a leg structure fixed to the four corners of the support frame, consisting of a pitch motor assembly, a roll motor assembly, an input transmission component, a thigh linkage component, a transmission linkage component, and a lower leg linkage component; The support frame includes a frame, and roll motor mounting holes and pitch motor mounting holes located at the four corners of the frame; The pitch motor assembly includes a connecting base at the bottom, a regular hexagonal short shaft and a cylindrical support shaft on both sides, and a first pitch motor and a second pitch motor located at the front and rear, respectively. The rolling motor assembly includes a rolling motor and a mounting plate fixed to the rolling motor, wherein the mounting plate has an internal hexagonal mounting hole in its center. The input transmission component includes a connector mounting hole at the bottom, a regular hexagonal boss at the top, and screw holes evenly distributed around the regular hexagonal boss in the circumference. The thigh linkage has a pitch motor mounting slot at the top and a lower leg connection hole at the bottom. The transmission linkage includes a main rod, and a first support rod and a second support rod located at both ends of the main rod; The lower leg connecting rod is provided with a connector mounting hole and a thigh connecting hole; The connecting base of the pitch motor assembly is fixedly connected to the pitch motor mounting slot at the top of the thigh linkage; the regular hexagonal short shaft of the pitch motor assembly is embedded in the internal hexagonal mounting hole of the roll motor assembly; the regular hexagonal boss of the input transmission component is embedded in the regular hexagonal mounting hole of the pitch motor assembly. The mounting plate of the roll motor assembly is fixedly installed in the roll motor mounting hole of the support frame; the cylindrical support shaft of the pitch motor assembly is installed in the pitch motor mounting hole through a spherical bearing; the second support rod of the transmission linkage is installed in the connector mounting hole of the input transmission component through a bearing; the lower leg connection hole of the thigh linkage is rotatably connected to the thigh connection hole of the lower leg linkage; the first support rod of the transmission linkage and the connector mounting hole of the lower leg linkage are rotatably connected through a bearing.

2. The quadruped robot dog structure with variable reduction ratio according to claim 1, characterized in that, The center points of the hexagonal mounting holes of the pitch motor assembly, the center points of the connecting holes of the input transmission components, the center points of the thigh connecting holes of the lower leg linkage, and the center points of the connecting holes of the lower leg linkage form a spatial four-bar linkage with four sides of unequal length.

3. The quadruped robot dog structure with variable reduction ratio according to claim 2, characterized in that, The included angle between the center point of the regular hexagonal mounting hole and the center point of the calf connecting hole, and the included angle between the center point of the connector mounting hole and the center point of the regular hexagonal boss, is 35-145°. The distance between the center point of the regular hexagonal mounting hole and the center point of the lower leg connecting hole is less than the distance between the center point of the first support rod and the center point of the second support rod of the transmission connecting rod. The distance between the center point of the connecting hole of the input transmission component and the center point of the regular hexagonal boss is less than the distance between the center point of the thigh connecting hole of the lower leg connecting rod and the center point of the connecting hole.

4. The quadruped robot dog structure with variable reduction ratio according to claim 3, characterized in that, The distance between the center point of the regular hexagonal mounting hole and the center point of the lower leg connecting hole is 350mm; The distance between the center point of the first support rod and the center point of the second support rod of the transmission linkage is 375mm. The distance between the center point of the connecting hole of the input transmission component and the center point of the regular hexagonal boss is 40mm. The distance between the center point of the thigh connection hole of the lower leg connecting member and the center point of the connecting member mounting hole is 65mm.

5. The quadruped robot dog structure with variable reduction ratio according to claim 4, characterized in that, The variable reduction ratio of the spatial four-bar linkage is 0.4~0.8, and the rotation angle between the lower leg link and the upper leg link is 0~85°.

6. The quadruped robot dog structure with variable reduction ratio according to claim 1, characterized in that, The axis of the output end of the pitch motor is perpendicular to and intersects the axis of the output end of the roll motor.

7. The quadruped robot dog structure with variable reduction ratio according to claim 1, characterized in that, A through hole is formed at the center of the regular hexagonal boss of the input transmission component.

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