CN110682976A - Multi-degree-of-freedom mechanical wheel leg structure of wheel leg combined type mobile robot - Google Patents

Abstract

The invention discloses a multi-degree-of-freedom mechanical wheel-leg structure of a wheel-leg compound mobile robot, whose wheel and leg movement modes can be flexibly switched, and effectively combine the high mobility of the wheeled type and the strong environmental adaptability of the legged type. ; The wheel legs have multiple degrees of freedom, which can realize all-round movement to adjust the body posture and center of gravity balance. Among them, damping springs are arranged at the knee joints of the wheel legs, and the buffering capacity of the springs is used to improve the adaptability of the leg joints when they are impacted by the ground. By controlling the motor, the lifting and stretching telescopic mechanism of the thigh lead screw slide table and the force feedback telescopic mechanism of the calf electric cylinder are coordinated to operate. The lockable swing mechanism of the hip joint chain drive can drive the mechanical wheel legs to swing along the rotation axis vertical to the ground. And the action in cooperation with the wheel hub steering mechanism can realize the omnidirectional driving function of the wheel legs or the variable wheelbase and wheelbase driving. The mechanical wheel legs have modular characteristics, as well as good dynamic ride comfort and high passability on complex terrain.

Description

A multi-degree-of-freedom mechanical wheel-leg structure of a wheel-leg compound mobile robot

technical field

The invention relates to the technical field of robots and automatic control, in particular to a multi-degree-of-freedom mechanical wheel-leg structure of a wheel-leg compound mobile robot.

Background technique

The application requirements of mobile robots in many fields such as military, agriculture and scientific research are becoming more and more extensive. Traditional mobile robots can be divided into wheeled, legged and crawler based on different driving methods. The most common application is the wheeled mobile robot, which has a relatively simple structure and control, high movement efficiency, and fast moving speed. The disadvantage is that it has poor adaptability to terrain. Legged robots are usually bipedal, quadrupedal, and hexapodal. Compared with wheeled robots, this type of robot has strong adaptability to terrain and strong ability to overcome obstacles. higher. Compared with the first two types of robots, the crawler robot has a large contact area with the ground and is suitable for moving on soil or loose ground. The wheel-leg compound mobile robot adopts an efficient wheel-leg compound walking mechanism, which can travel in a variety of motion modes under different road conditions and terrain environments. When the terrain is leveled, it mainly relies on the wheeled mechanism to move forward, which has high moving efficiency. For complex and rugged terrain, the wheel-leg compound structure is adopted, which greatly improves the robot's ability to adapt to the terrain, has strong off-road performance, and can pass extreme terrain conditions such as vertical obstacles and trenches. Due to its strong terrain adaptability, low energy consumption and fast speed, it has developed rapidly in recent years, and is widely used in unmanned transportation, unmanned mine clearance, unmanned weapons carrying military fields and agriculture, logistics, rescue and underwater. Construction civil field.

The invention patent 201711105290.6 discloses "a wheel-leg structure of a wheel-leg compound robot". The wheel-leg structure of the robot consists of an actuator, a tripod, a damping spring, a double wishbone suspension, a steering motor, wheel legs and a wheel hub. The drive wheel of the motor is composed. The wheel-leg structure realizes the movement in the height direction by controlling the actuator, but the disadvantage is that the length of the mechanical leg is fixed, and the length of the mechanical leg cannot be changed; at the same time, the hip joint cannot rotate freely horizontally.

In the invention patent 201910054295.3, "a wheel-leg structure of a wheel-leg compound robot" is proposed. The mechanical leg structure consists of three parts: a leg section, a foot section and a wheeled mechanism. Both the wheel mechanism of the first segment of the foot segment and the end of the foot segment can be used as the ground contact end, and the ground contact end of the foot segment is controlled by the controller to realize the switch between the wheel type and the leg type movement. However, the wheeled movement has a narrower range of motion than the legged movement; at the same time, only two legs can be controlled at the same time through the slider movement, and the independent control of a single leg cannot be achieved.

SUMMARY OF THE INVENTION

In order to avoid the shortcomings of the prior art, the present invention proposes a multi-degree-of-freedom mechanical wheel-leg structure of a wheel-leg compound mobile robot.

The technical scheme adopted by the present invention to solve its technical problems is: including a hip joint chain drive locking swing mechanism, a thigh lead screw sliding table lifting type tensioning and retracting mechanism, a knee joint shock-resistant spring buffer mechanism, a calf electric cylinder force feedback telescopic mechanism, a wheel hub The large-angle steering structure and the electric wheel hub are characterized in that the hip joint chain transmission lockable swing mechanism includes a frame top connecting plate, a frame bottom connecting plate, a main drive shaft, a driving sprocket, a first hip joint support plate, and a slave drive shaft. , the lower connecting plate of the sliding table, the driven sprocket, the chain, the second hip joint support plate, the frame bottom connecting plate, the driving sprocket, the main drive shaft and the chain tension bracket, the frame top connecting plate and the frame bottom connecting plate Connected with the center frame, the first servo motor and the first reducer are fixedly connected with the motor connecting frame plate and located on the upper part of the center frame, the main drive shaft is respectively connected with the first reducer and the driving sprocket, and the first hip joint support plate The upper end is fixedly connected to the frame top connecting plate, the lower end is fixedly connected to the frame bottom connecting plate, the upper end of the second hip joint support plate is connected to the frame top connecting plate, the lower end is fixedly connected to the frame bottom connecting plate, and the electromagnetic brake bracket is fixed to the frame top connecting plate. The upper part of the tooth-clamped electromagnetic brake is fixedly connected with the electromagnetic brake bracket, the lower part is connected with the slave drive shaft, the upper connecting plate of the sliding table is connected with the frame top connecting plate, the slave drive shaft is connected with the driven sprocket, the frame bottom connecting plate is connected with the sliding The connecting plate under the stage is connected by cylindrical roller bearings; the first servo motor drives the main drive shaft and the driving sprocket to rotate through the first reducer, and drives the slave drive shaft to rotate through the chain drive, so as to realize the rotation of the mechanical leg around the driven shaft ;

The lifting and stretching mechanism of the thigh lead screw slide table includes a second servo motor, an upper thigh connecting plate, a support rod, a lower thigh connecting plate, a slider, a sliding table frame, a motor support seat, a second reducer, and a knee joint inner plate. connecting rod, the lead screw slide table frame is fixedly connected with the slide table upper connecting plate and the slide table lower connecting plate; the second servo motor and the second reducer are connected with the motor support seat, and the motor support seat is fixed with the lead screw slide table frame The support rod is fixedly connected with the slider and the upper thigh connecting plate, and the lead screw slide table frame is connected with the lower thigh connecting plate; Quadrilateral mechanism; the second servo motor drives the ball screw to rotate through the second reducer and the coupling, the slider moves up and down to drive the support rod to rotate, realizes the vertical rotation of the parallel four-bar linkage mechanism, and completes various lifting actions of the mechanical leg ;

The knee joint shock-resistant spring buffer mechanism includes a knee link, a second link optical axis, an outer knee link, an inner knee link, an optical axis of the first link, a spring connecting plate, a first damping spring, The second damping spring, the optical axis of the first connecting rod passes through the inner connecting rod of the knee joint and the upper thigh connecting rod and is connected with the inner connecting rod of the knee joint through a deep groove ball bearing, and the lower connecting rod of the thigh is hinged with the inner connecting rod of the knee joint, The inner link of the knee joint, the outer link of the knee joint and the lower link of the lower leg are hinged, the first damping spring is fixedly connected with the inner link of the knee joint and the outer link of the knee joint, and the second damping spring is connected with the inner link of the knee joint and the knee joint The outer connecting rod is fixedly connected, the outer side of the first damping spring and the second damping spring are prevented from moving radially by the spring connecting plate, and the outer side of the spring connecting plate is provided with a locking nut to prevent its axial moving. There are anti-loosening nuts at both ends of the optical axis of the second connecting rod to prevent it from moving axially. There is a chute on the knee connecting rod. The outer connecting rod of the knee joint moves relative to the knee connecting rod. rod, which buffers the external impact;

The calf electric cylinder force feedback telescopic mechanism includes a third reducer, a third servo motor, an upper calf link, a third link optical axis, a wheel hub frame, a fourth link optical axis, a calf lower link, and an electric cylinder The optical axis of the second connecting rod passes through the upper link of the lower leg and the outer link of the knee joint is connected with the upper link of the lower leg through a deep groove ball bearing, and the inner link of the knee joint, the outer link of the knee joint and the lower link of the lower leg are hinged ; The optical axis of the third connecting rod passes through the upper connecting rod of the lower leg and the hub frame and is connected with the upper connecting rod of the lower leg through the deep groove ball bearing, and the optical axis of the fourth connecting rod passes through the lower connecting rod of the lower leg and the hub frame and the lower connecting rod of the lower leg through the deep groove ball bearing. The groove ball bearing is connected, the rod end of the electric cylinder is connected with the upper link of the lower leg, the cylinder end of the electric cylinder is connected with the lower link of the lower leg, the upper link of the lower leg and the lower link of the lower leg are connected with the outer link of the knee and the hub in the wheel steering structure The frame consists of a parallel four-bar linkage mechanism; the third servo motor drives the electric cylinder piston rod to move linearly through the third reducer and the coupling, so as to realize the rotation of the parallelogram mechanism around the knee joint buffer structure, and complete various actions of the mechanical leg.

The large-angle steering structure of the wheel hub includes a swinging hydraulic cylinder, a wheel hub rotating shaft, a wheel, a wheel hub motor, a brake bracket, a wheel hub side plate, a wheel hub rotation stop plate, and a wheel hub transverse plate. The upper link and the upper mounting hole of the hub frame are connected by the optical axis of the third link, the lower link of the lower leg and the lower mounting hole of the hub frame are connected by the optical axis of the fourth link, and the hub rotating shaft passes through the bottom of the hub frame and the hub horizontal plate through the method The flange is fixedly connected, the hub rotating shaft and the hub frame are connected by deep groove ball bearings, the swing hydraulic cylinder is connected with the hub rotating shaft, the hub transverse plate is connected with the hub side plate, the hub rotation stop plate is fixedly connected with the hub side plate, the hub rotation stop plate is connected Hinged with the brake bracket, the hub motor is located on the inner side of the wheel and is firmly connected with the side plate of the hub; when the pressure oil enters the oil chamber of the swing hydraulic cylinder, it pushes the wheel hub shaft to rotate, and the oil in the other chamber is discharged back to the oil chamber; when the pressure oil reverses When entering the oil cavity, the hub rotating shaft moves in the opposite direction, thereby realizing the steering of the hub; by controlling the flow direction of the pressure oil, the hub rotating shaft can achieve a large angle rotation of -178° to 178°.

beneficial effect

The multi-degree-of-freedom mechanical wheel-leg structure of a wheel-leg compound mobile robot proposed by the present invention has the characteristics of modularization, and the movement modes of the wheel and the leg can be switched flexibly, which effectively combines the high mobility of the wheel type and the legs and feet. It has strong environmental adaptability; the wheel legs have multiple degrees of freedom, which can realize all-round motion to adjust the body posture and center of gravity balance.

The multi-degree-of-freedom mechanical wheel leg structure of the present invention has four high stiffness damping springs arranged at the knee joints of the mechanical wheel legs, and the buffer capacity of the springs is used to improve the passive adaptability of the leg joints when they are impacted by the ground, and avoid the driving device and the Structure is destroyed.

The multi-degree-of-freedom mechanical wheel-leg structure of the present invention can control the motor to make the thigh lead screw slide platform lift and stretch the telescopic mechanism and the calf electric cylinder force feedback telescopic mechanism to operate in coordination, so that the power wheel at the end of the leg can reach a larger space range, Ensure that the fuselage has sufficient support area, spanning width, stepping depth and climbing height in complex terrain environments, ensuring the balance of the fuselage center of gravity and completing obstacle crossing. The design of the lifting and stretching telescopic mechanism of the thigh lead screw slide and the force feedback telescopic mechanism of the calf electric cylinder adopts the tension bearing method, which effectively reduces the weight of the mechanical wheel leg and the weight of the driving device, and realizes the lightweight of the wheel leg.

The multi-degree-of-freedom mechanical wheel leg structure of the present invention, the hip joint chain drive can lock the swing mechanism, and can drive the mechanical wheel leg to swing along the rotation axis vertical to the ground. A tooth-type electromagnetic brake locking mechanism is designed at the swing joint, which can maintain the swing angle and resist torsional impact force during the movement on uneven ground through control commands. In cooperation with the wheel hub steering mechanism, the omnidirectional driving function of the mechanical wheel legs or the variable wheelbase and wheelbase driving can be realized.

The motor hydraulic braking unit of the multi-degree-of-freedom mechanical wheel-leg structure of the present invention can lock part of the degrees of freedom to realize switching between wheel-type movement and leg-foot walking. The brake unit also enables the in-wheel motors to have service and parking brake functions.

Description of drawings

The multi-degree-of-freedom mechanical wheel-leg structure of a wheel-leg compound mobile robot of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

Figure 1 is a front view of the multi-degree-of-freedom mechanical wheel-leg structure of the wheel-leg compound mobile robot.

FIG. 2 is a schematic diagram of a multi-degree-of-freedom mechanical wheel-leg structure of a wheel-leg compound mobile robot.

FIG. 3 is a front view of the lockable swing mechanism of the hip joint chain drive.

Figure 4 is a schematic view of the assembly of the lockable swing mechanism of the hip joint chain drive.

Figure 5 is a front view of the lifting and stretching mechanism of the thigh lead screw slide table.

Figure 6 is a schematic diagram of the assembly of the lifting and stretching mechanism of the thigh lead screw slide table.

FIG. 7 is a front view of a knee joint shock-resistant spring buffer mechanism.

FIG. 8 is a schematic diagram of the assembly of the anti-shock spring buffer mechanism of the knee joint.

FIG. 9 is a front view of the force feedback telescopic mechanism of the calf electric cylinder.

Figure 10 is a schematic diagram of the assembly of the force feedback telescopic mechanism of the calf electric cylinder.

Figure 11 is a front view of the wheel hub's large-angle steering structure.

Figure 12 is a schematic diagram of the assembly of the wheel hub's large-angle steering structure.

pictured

1. Center frame 2. The first reducer 3. The first servo motor 4. The motor connecting frame plate 5. The frame top connecting plate 6. The electromagnetic brake bracket 7. The toothed electromagnetic brake 8. The sliding table upper connecting plate 9. First hip joint support plate 10. Slave drive shaft 11. Lower connecting plate of sliding table 12. Driven sprocket 13. Chain 14. Second hip joint support plate 15. Frame bottom connecting plate 16. Driving sprocket 17. Main drive Shaft 18. Chain tensioning bracket 19. Second servo motor 20. Upper thigh connecting plate 21. Support rod 22. Lower thigh connecting plate 23. Slider 24. Slide table frame 25. Motor support seat 26. Second reducer 27 . Knee link 28. Second link optical axis 29. Knee joint outer link 30. Knee joint inner link 31. First link optical axis 32. Spring connecting plate 33. First damping spring 34. Second Damping spring 35. Third reducer 36. Third servo motor 37. Lower leg link 38. Third link optical axis 39. Hub frame 40. Fourth link optical axis 41. Lower leg link 42. Electric cylinder 43. Swing hydraulic cylinder 44. Wheel hub shaft 45. Wheel 46. Wheel hub motor 47. Brake bracket 48. Wheel hub side plate 49. Hub rotation stop plate 50. Hub cross plate

Detailed ways

This embodiment is a multi-degree-of-freedom mechanical wheel-leg structure of a wheel-leg compound mobile robot.

Referring to Figures 1 to 12, the multi-degree-of-freedom mechanical wheel-leg structure of the wheel-leg compound mobile robot in this embodiment is driven by the hip joint chain to lock the swing mechanism, the thigh screw slide table lifting and stretching mechanism, and the knee joint impact resistance. It is composed of a spring buffer mechanism, an electric cylinder force feedback telescopic mechanism for the calf, a large-angle steering structure of the wheel hub and an electric wheel hub. Four mechanical wheel legs are symmetrically installed at the four corners of the center frame. Each mechanical wheel leg has six degrees of freedom relative to the center frame. Among them, the lockable swing mechanism of the hip joint chain transmission includes the frame top connecting plate 5, the frame bottom connecting plate 15, the main transmission shaft 17, the driving sprocket 16, the first hip joint support plate 9, the slave transmission shaft 10, the sliding table lower connection Plate 11, driven sprocket 12, chain 13, second hip joint support plate 14, frame bottom connecting plate 15, driving sprocket 16, main drive shaft 17, chain tension bracket 18, hip joint chain drive type lockable swing The top connecting plate 5 and the bottom connecting plate 15 of the middle frame of the mechanism are fixed to the central frame 1 by screws, the first servo motor 3 and the first reducer 2 are fixed to the motor connecting frame plate 4 by screws, and the main drive shaft 17 is connected to the frame. The first reducer 2 is connected by a flat key, the main drive shaft 17 and the driving sprocket 16 are connected by two flat keys, the upper end of the first hip joint support plate 9 and the frame top connecting plate 5 are fixedly connected by screws, and the first hip joint support The lower end of the plate 9 and the frame bottom connecting plate 15 are fixed by screws, the upper end of the second hip joint support plate 14 and the frame top connecting plate 5 are fixed by screws, and the lower end of the second hip joint support plate 14 and the frame bottom connecting plate 15 are fixed by screws. The electromagnetic brake bracket 6 and the frame top connecting plate 5 are fixedly connected by screws, the upper teeth of the toothed electromagnetic brake 7 and the electromagnetic brake bracket 6 are fixed by screws, and the lower teeth of the toothed electromagnetic brake 7 are connected to the driven shaft 10 through the flat The upper connecting plate 8 of the sliding table is connected with the frame top connecting plate 5 through cylindrical roller bearings, the transmission shaft 10 and the driven sprocket 12 are connected by two flat keys, and the frame bottom connecting plate 15 is connected with the lower connecting plate of the sliding table. 11 is supported by a cylindrical roller bearing, and the axial movement of the lower connecting plate 11 of the sliding table is prevented by loosening the nut from the lower end of the transmission shaft 10 . The first servo motor 3 drives the main drive shaft 17 and the driving sprocket 16 to rotate through the first reducer 2 and the coupling, and drives the slave drive shaft 10 to rotate through the chain drive 13, so as to realize the rotation of the mechanical leg around the driven shaft. In order to complete various expected actions of the mechanical leg.

The lifting and stretching mechanism of the thigh screw slide table includes the second servo motor 19, the upper thigh connecting plate 20, the support rod 21, the lower thigh connecting plate 22, the slider 23, the sliding table frame 24, the motor support seat 25, the second deceleration 26 and the inner link 30 of the knee joint, in the lifting and stretching mechanism of the thigh screw slide table, the upper and lower parts of the frame side of the screw slide table frame 24 have 6 threaded holes respectively, and the upper connecting plate 8 of the slide table is connected to the screw The upper threaded holes of the rod sliding table frame 24 are fixedly connected by 6 screws, and the lower connecting plate 11 of the sliding table and the lead screw sliding table frame 24 are fixedly connected by 6 screws. The second servo motor 19 and the second reducer 26 are fixedly connected to the motor support base 25 by screws, the motor support base 25 is fixed to the lead screw slide frame 24 by screws, the support rod 21 is connected to the slider 23 and the upper thigh connecting plate 20 The screw slide frame 24 and the lower thigh connecting plate 22 are fixedly connected by screws. All the above screw fixing positions need to be installed with loosening nuts to prevent them from moving axially. The lead screw slide frame 24, the upper thigh connecting plate 20, the lower thigh connecting plate 22 and the inner link 30 of the knee joint form a parallelogram mechanism. The second servo motor 19 drives the ball screw to rotate through the second reducer 26 and the coupling, and the slider 23 moves up and down to drive the support rod 21 to rotate, thereby realizing the rotation of the parallelogram mechanism to complete various lifting actions of the mechanical legs. .

The knee joint anti-shock spring buffer mechanism includes a knee link 27, a second link optical axis 28, a knee joint outer link 29, a knee joint inner link 30, a first link optical axis 31, a spring connecting plate 32, and a second link. A damping spring 33, a second damping spring 34, in the knee joint anti-shock spring buffer mechanism, the optical axis 31 of the first link passes through the inner link 30 of the knee joint and the upper thigh connecting plate 20 at the same time, and the optical axis 31 of the first link It is connected with the inner link 30 of the knee joint through deep groove ball bearings, the lower thigh connecting plate 22 and the inner link 30 of the knee joint are hinged with screws, and the inner link 30 of the knee joint, the outer link 29 of the knee joint and the lower link 41 of the lower leg pass through The pin is hinged, the first damping spring 33 is fixed with the knee joint inner link 30 and the knee joint outer link 29 by screws, and the second damping spring 34 is fixed with the knee joint inner link 30 and the knee joint outer link 29 by screws. , the outer side of the first damping spring 33 and the second damping spring 34 are prevented from moving radially by the spring connecting plate 32, the outside of the spring connecting plate 32 is prevented from moving axially by loosening the nut, the optical axis 31 of the first connecting rod and the second connecting plate 32 are prevented from moving axially. The two ends of the optical axis 28 of the connecting rod are prevented from moving in the axial direction by loosening the nuts, and the outer side of the pin is prevented from moving in the axial direction by the circlip. The knee link 27 is provided with a chute. Under the external impact, the spring shortens, and the knee joint outer link 29 moves relative to the knee link 27. The buffering capacity of the spring is used to improve the leg structure when it is impacted by the ground. passive adaptability.

The calf electric cylinder force feedback telescopic mechanism includes a third reducer 35, a third servo motor 36, an upper calf link 37, a third link optical axis 38, a hub frame 39, a fourth link optical axis 40, and a lower calf link. In the rod 41, the electric cylinder 42, and the calf electric cylinder force feedback telescopic mechanism, the optical axis 28 of the second link passes through the upper link 37 of the calf and the outer link 29 of the knee joint at the same time, and the optical axis 28 of the second link passes through the upper link 37 of the lower leg and the outer link 29 of the knee joint. The connecting rod 37 is supported by the deep groove ball bearing, the inner connecting rod 30 of the knee joint, the outer connecting rod 29 of the knee joint and the lower connecting rod 41 of the lower leg are hinged by pins, and the optical axis 38 of the third connecting rod passes through the upper connecting rod 37 of the lower leg and the hub frame 39. The optical axis 38 of the third connecting rod and the upper connecting rod 37 of the lower leg are supported by deep groove ball bearings, the optical axis 40 of the fourth connecting rod passes through the lower connecting rod 41 of the lower leg and the hub frame 39, and the optical axis 40 of the fourth connecting rod is connected to the lower leg of the lower leg. The lower connecting rod 41 is supported by the deep groove ball bearing, the cylinder side of the electric cylinder 42 is hinged with the lower leg connecting rod 41 by screws, and the rod end of the electric cylinder 42 is hinged with the upper leg connecting rod 37 by screws. The upper calf link 37 , the lower calf link 42 , the outer knee link 29 and the hub frame 39 in the wheel hub steering structure constitute a parallel four-bar linkage mechanism. The third servo motor 36 drives the piston rod of the electric cylinder 42 to move linearly through the third reducer 35 and the coupling, thereby realizing the rotation of the parallelogram mechanism around the knee joint buffer structure to complete various actions of the mechanical leg.

The wheel hub large-angle steering structure includes a swing hydraulic cylinder 43, a wheel hub rotating shaft 44, a wheel 45, a wheel hub motor 46, a brake bracket 47, a wheel hub side plate 48, a wheel hub rotation stop plate 49, and a wheel hub cross plate 50. The wheel hub in the wheel hub large-angle steering structure The upper and lower parts of the frame 39 have two mounting holes respectively, the upper link 37 of the lower leg and the upper mounting hole of the hub frame 39 are connected by the third link optical axis 38, and the lower link 41 of the lower leg and the lower mounting hole of the hub frame 39 are connected by the fourth link. The rod optical axis 40 is connected, the hub rotating shaft 44 passes through the bottom of the hub frame 39 and is fixedly connected with the hub transverse plate 50 through the flange plate, the hub rotating shaft 44 and the hub frame 39 are supported by deep groove ball bearings, and the swing hydraulic cylinder 43 and the hub rotating shaft 44 Through the flat key connection, the hub transverse plate 50 and the hub side plate 48 are fixedly connected by screws, the hub rotation stop plate 49 and the hub side plate 48 are fixed by screws, the hub rotation stop plate 49 and the brake bracket 47 are hinged by screws, and the hub motor 46 Fixed on the inner side of the wheel 45 , the hub motor 46 is fixed on the hub side plate 48 . When the pressure oil enters the oil cavity of the oscillating hydraulic cylinder 43, the wheel hub shaft 44 is pushed to rotate, and the oil in the other cavity is discharged back to the oil cavity; when the pressure oil enters the oil cavity in the reverse direction, the wheel hub shaft 44 moves in the opposite direction, thereby realizing the wheel hub 's turning. By controlling the flow direction of the pressure oil, the hub rotating shaft 44 can realize a large-angle rotation of -178° to 178°, so as to realize the omnidirectional movement of the robot.

In this embodiment, the central frame 1 is connected to each mechanical wheel leg or the controller and various equipment used for loading the whole machine, four mechanical wheel legs are installed at the four corners of the central frame 1, and each mechanical wheel leg has six The degree of freedom can be controlled by the claw-type electromagnetic brake or the motor brake, respectively, so that a part of the degrees of freedom can be locked to realize the switching between wheeled movement and leg-foot walking. The mechanical wheel legs are controlled by various servo motors, electric cylinders, oscillating hydraulic cylinders and wheel hub motors, and transmit motion through a series of leg members and rotating shafts, so that the wheel legs can move in three dimensions relative to the center frame.

Claims (2)

1. A multi-degree-of-freedom mechanical wheel leg structure of a wheel leg combined type mobile robot comprises a hip joint chain transmission locking swing mechanism, a thigh lead screw sliding table lifting type tensioning telescopic mechanism, a knee joint impact-resistant spring buffer mechanism, a shank electric cylinder force feedback telescopic mechanism, a wheel hub large-angle steering structure and an electric wheel hub The upper end of a first hip joint support plate is fixedly connected with a frame top connecting plate, the lower end of the first hip joint support plate is fixedly connected with a frame bottom connecting plate, the upper end of a second hip joint support plate is connected with the frame top connecting plate, the lower end of the second hip joint support plate is fixedly connected with the frame bottom connecting plate, an electromagnetic brake support is fixedly connected with the frame top connecting plate, the upper part of a tooth-embedded electromagnetic brake is fixedly connected with the electromagnetic brake support, the lower part of the tooth-embedded electromagnetic brake support is connected with a driven shaft, a sliding table upper connecting plate is connected with the frame top connecting plate, the driven shaft is connected with a driven chain wheel, and the; the first servo motor drives the main transmission shaft and the driving chain wheel to rotate through the first speed reducer, and drives the driven transmission shaft to rotate through chain transmission, so that the mechanical legs rotate around the driven shaft;

the thigh screw sliding table lifting, tensioning and stretching mechanism comprises a second servo motor, a thigh upper connecting plate, a supporting rod, a thigh lower connecting plate, a sliding block, a sliding table frame, a motor supporting seat, a second speed reducer and a knee joint inner connecting rod, wherein the screw sliding table frame is fixedly connected with the sliding table upper connecting plate and the sliding table lower connecting plate; the second servo motor and the second speed reducer are connected with a motor support seat, the motor support seat is fixedly connected with a lead screw sliding table frame, a support rod is fixedly connected with a slide block and a thigh upper connecting plate, and the lead screw sliding table frame is connected with a thigh lower connecting plate; the lead screw sliding table frame, the upper thigh connecting plate, the lower thigh connecting plate and the knee joint inner connecting rod form a parallelogram mechanism; the second servo motor drives the ball screw to rotate through a second speed reducer and a coupler, the slide block moves up and down to drive the support rod to rotate, the vertical direction rotation of the parallel four-bar linkage mechanism is realized, and various lifting actions of the mechanical leg are completed;

the knee joint impact-resistant spring buffer mechanism comprises a knee connecting rod, a second connecting rod optical axis, a knee joint outer connecting rod, a knee joint inner connecting rod, a first connecting rod optical axis, a spring connecting plate, a first damping spring and a second damping spring, wherein the first connecting rod optical axis penetrates through the knee joint inner connecting rod and a thigh upper connecting plate to be connected with the knee joint inner connecting rod through a deep groove ball bearing, a thigh lower connecting plate is hinged with the knee joint inner connecting rod, the knee joint outer connecting rod and a shank lower connecting rod are hinged, the first damping spring is fixedly connected with the knee joint inner connecting rod and the knee joint outer connecting rod, the second damping spring is fixedly connected with the knee joint inner connecting rod and the knee joint outer connecting rod, the outer sides of the first damping spring and the second damping spring are prevented from radial movement through the spring connecting plate, the outer side of the spring connecting plate is provided with a check nut to prevent axial movement, and, the knee connecting rod is provided with a sliding chute, the knee joint outer connecting rod moves relative to the knee connecting rod, and the damping spring is used for connecting the knee inner connecting rod and the knee outer connecting rod to play a role in buffering external impact;

the shank electric cylinder force feedback type telescopic mechanism comprises a third speed reducer, a third servo motor, a shank upper connecting rod, a third connecting rod optical axis, a hub frame, a fourth connecting rod optical axis, a shank lower connecting rod and an electric cylinder, wherein the second connecting rod optical axis penetrates through the shank upper connecting rod to be connected with a knee joint outer connecting rod and the shank upper connecting rod through deep groove ball bearings, and a knee joint inner connecting rod, the knee joint outer connecting rod and the shank lower connecting rod are hinged; the optical axis of a third connecting rod penetrates through an upper shank connecting rod and a hub frame to be connected with the upper shank connecting rod through a deep groove ball bearing, the optical axis of a fourth connecting rod penetrates through a lower shank connecting rod and the hub frame to be connected with the lower shank connecting rod through the deep groove ball bearing, the rod end of an electric cylinder is connected with the upper shank connecting rod, the cylinder end of the electric cylinder is connected with the lower shank connecting rod, and the upper shank connecting rod, the lower shank connecting rod, a knee outer connecting rod and the hub frame in a hub steering structure form a parallel four-bar mechanism; the third servo motor drives the piston rod of the electric cylinder to move linearly through the third speed reducer and the coupler, so that the parallelogram mechanism rotates around the knee joint buffer structure, and various actions of the mechanical legs are completed.

2. The multi-degree-of-freedom mechanical wheel leg structure of the wheel leg combined type mobile robot as claimed in claim 1, wherein the wheel hub large-angle steering structure comprises a swing type hydraulic cylinder, a wheel hub rotating shaft, a wheel, a wheel hub motor, a brake bracket, a wheel hub side plate, a wheel hub rotation stopping plate and a wheel hub transverse plate, wherein mounting holes are respectively formed in the upper portion and the lower portion of a wheel hub frame, a shank upper connecting rod is connected with the mounting hole in the upper portion of the wheel hub frame through a third connecting rod optical axis, a shank lower connecting rod is connected with the mounting hole in the lower portion of the wheel hub frame through a fourth connecting rod optical axis, the wheel hub rotating shaft penetrates through the bottom of the wheel hub frame and is fixedly connected with the wheel hub transverse plate through a flange plate, the wheel hub rotating shaft is connected with the wheel hub rotating shaft through a deep groove ball bearing, the hub motor is positioned on the inner side of the wheel and fixedly connected with the hub side plate; when pressure oil enters an oil cavity of the swing type hydraulic cylinder, the rotating shaft of the hub is pushed to rotate, and oil in the other cavity is discharged back to the oil cavity; when the pressure oil reversely enters the oil cavity, the rotating shaft of the hub reversely moves, so that the steering of the hub is realized; by controlling the flow direction of the pressure oil, the hub rotating shaft can realize large-angle rotation of-178 degrees.

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