A hopping wheel-foot mobile robot
By combining adaptive shock-absorbing legs and active attitude control, the stability and attitude control problems of wheeled robots in complex environments have been solved, enabling smooth switching between wheeled driving and legged jumping and efficient energy utilization, thereby improving the reliability and efficiency of civil aviation flight area operations.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CIVIL AVIATION UNIV OF CHINA
- Filing Date
- 2026-03-25
- Publication Date
- 2026-05-29
AI Technical Summary
The existing shock absorption structure of wheeled and legged robots is poorly designed and cannot effectively absorb shocks in stages throughout the entire stroke range. It rebounds significantly upon landing and is prone to instability. Furthermore, the wheel-leg switching and shock absorption system are independent of each other, resulting in large structural redundancy and making it difficult to achieve adaptive adjustment between wheeled driving filtering and legged jumping buffering.
The adaptive shock-absorbing leg structure, including thigh link, lower leg link and rotating joint, is adopted. It uses torsion springs to absorb impact energy, and through the cooperation of active attitude control and adaptive shock-absorbing legs, it realizes real-time closed-loop correction of the fuselage attitude and graded absorption of impact energy. Combined with the coordinated design of wheel and foot structure and shock absorption system, it reduces the redundancy and weight of the whole machine.
It enables robots to operate stably in complex environments, improves landing stability and sensor accuracy, ensures smooth switching between wheeled movement and legged hopping, reduces mechanical redundancy and weight, and improves energy utilization efficiency.
Smart Images
Figure CN122101352A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of mobile robot technology, and more particularly to a wheeled mobile robot capable of jumping. Background Technology
[0002] As the core area of an airport, the operational efficiency and safety level of the civil aviation flight area directly affect the operational quality of the air transport system. Currently, ground support operations are highly dependent on manual labor: baggage transfer still generally relies on manual handling, resulting in high labor costs and difficulty in recruiting workers; aircraft skin inspections depend on manual visual inspection, which is inefficient and prone to omissions; high-altitude operations still require the use of high-altitude platforms, posing significant safety hazards; and the complex apron environment makes it difficult for existing AGVs to detour or stop when encountering obstacles as small as centimeters, hindering continuous coverage of the entire area.
[0003] Industry and academia have developed specialized robots for the above scenarios, such as luggage-grabbing robots, wall-climbing inspection robots, and cleaning robots. These robots have achieved remarkable results in their respective fields, but they are limited in function, difficult to switch tasks flexibly, and their mobility is mainly based on pure wheeled or pure adhesive structures, which limits their obstacle-crossing capabilities.
[0004] Wheel-legged hybrid robots possess advantages in both speed and obstacle-crossing, but research on them in civil aviation flight areas is still lacking, and existing technologies suffer from two common problems: First, the shock absorption design is flawed, making it unable to effectively absorb impacts in stages throughout the entire stroke range. This leads to rebound and instability upon landing, affecting sensor accuracy. Secondly, the wheel-foot switching and shock absorption system do not form a structural synergy. The independent setting of the two mechanisms results in large redundancy and high weight, making it difficult to achieve adaptive adjustment between wheel-type driving filtering and foot-type jumping buffer.
[0005] To address these issues, a hopping wheel-legged mobile robot is proposed. Summary of the Invention
[0006] The purpose of this invention is to solve the problems of unreasonable shock absorption structure design in existing wheeled and legged robots, which cannot effectively absorb shock in stages throughout the entire stroke range, have obvious rebound and are prone to instability upon landing, and have wheel-leg switching and shock absorption systems that are independent of each other, resulting in large structural redundancy and difficulty in achieving adaptive adjustment between wheeled driving filtering and legged jumping buffer. Therefore, this invention proposes a hopping wheeled and legged mobile robot.
[0007] To achieve the above objectives, the present invention adopts the following technical solution: A hopping wheeled mobile robot includes a body with four hopping motors on both sides of the body. The output ends of the hopping motors are connected to adaptive shock-absorbing legs. A travel component is provided on the side of the adaptive shock-absorbing legs away from the body. The adaptive shock-absorbing leg includes a thigh link, a lower leg link, and a rotating joint. The upper end of the thigh link is connected to the corresponding jumping motor, and the lower end of the thigh link is connected to the upper end of the lower leg link through the rotating joint. The rotating joint includes a plug screw, a flange bearing, a washer, and a torsion spring. The plug screw passes through the flange bearing, the thigh link, the washer, the torsion spring, and the lower leg link in sequence, hinged to the thigh link and the lower leg link. The driving assembly includes a motor mounting base, with a bearing retaining ring on the outer side wall of the motor mounting base. A driving motor is embedded in the motor mounting base. A connecting seat is provided on the side of the motor mounting base away from the machine body. A wheel mounting base is rotatably connected in the connecting seat. One end of the wheel mounting base is connected to the output end of the driving motor, and a Mecanum wheel is fixedly installed at the other end of the wheel mounting base.
[0008] Preferably, the two ends of the torsion spring are fixed to the middle of the thigh link and the middle of the lower leg link, respectively, to absorb impact energy and assist the leg in recovery during jump landing.
[0009] Preferably, the restoring torque and energy absorption of the torsion spring are calculated according to the following formula: In the formula: The restoring torque generated by the torsion spring, This refers to the torsional stiffness of the torsion spring. The torsion spring absorbs the impact kinetic energy. This is the torsion angle of the torsion spring.
[0010] Preferably, the formulas for calculating the robot's ground clearance speed and jump height during the jump are as follows: In the formula: The instantaneous velocity upon leaving the ground. The acceleration generated by the jump motor drive, To speed up the process, For jump height, It is the acceleration due to gravity. For the time required to clear the space.
[0011] Preferably, the relationship between the landing impact force and the deformation of the torsion spring is as follows: In the formula: For the impact force during landing, This is the damping coefficient of the torsion spring. To the torsion angle of the torsion spring, This represents the rate of change of the torsion angle.
[0012] Preferably, the two lower leg connecting rods located on the same side of the body are respectively fixed to both sides of the same bearing retaining ring.
[0013] Preferably, limit rings are fixedly installed on both sides of the machine body corresponding to the jump motors. The limit rings are sleeved on the outer periphery of the jump motor output shaft to limit the swing angle range of the thigh linkage relative to the machine body.
[0014] Preferably, the active attitude control employs a PID control algorithm to achieve closed-loop adjustment of the fuselage attitude, and its core control formula is as follows: In the formula: The output control quantity for the jump motor. This is the proportionality coefficient; The integral coefficient is... The differential coefficients are... for Constant deviation in fuselage attitude, As an integral variable, the output speed and torque of the jump motor are adjusted in real time through this formula to ensure the stability of the aircraft's posture.
[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention, through the combined action of active attitude control and adaptive shock-absorbing legs, achieves real-time closed-loop correction of the robot's attitude throughout the entire process of jumping off the ground, adjusting attitude in the air, and recovering upon landing. This ensures that the wheeled mobile structure is always facing downwards in preparation for landing, and enables smooth and controllable switching between wheeled movement and legged jumping modes. This provides a reliable guarantee for the robot to operate continuously and stably in complex apron environments.
[0016] 2. This invention utilizes the combined use of the thigh link, lower leg link, and rotating joint, along with a torsion spring, to achieve graded absorption and dissipation of impact energy throughout the entire stroke range. This effectively reduces the peak impact value at the moment of landing after takeoff, and the restoring torque of the torsion spring assists in the smooth return of the leg, significantly improving the robot's landing stability and sensor accuracy.
[0017] 3. This invention achieves structural synergy between the wheel-foot structure and the shock absorption system by fixing the lower leg connecting rods of the two adaptive shock-absorbing legs located on the same side of the machine body to the same travel component. This ensures the filtering effect of the torsion spring on the high-frequency micro-vibrations of the ground during wheel travel, and meets the adaptive requirements for buffering performance during foot jumping. It effectively reduces the redundancy and weight of the whole machine and improves the integration and energy utilization efficiency of the mechanism. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the overall structure of a hopping wheeled mobile robot proposed in this invention; Figure 2 This is a structural assembly diagram of the body and adaptive shock-absorbing legs in a jumping wheeled mobile robot proposed in this invention; Figure 3 This is a structural assembly diagram of the body, jumping motor, and limiting ring of a jumping wheeled mobile robot proposed in this invention; Figure 4 This is a structural assembly diagram of the rotating joint in a hopping wheeled mobile robot proposed in this invention; Figure 5 This is a schematic diagram of the driving component and the lower leg linkage in a jumping wheeled mobile robot proposed in this invention; Figure 6 This is a schematic diagram of the driving component in a hopping wheeled mobile robot proposed in this invention; Figure 7 This is a structural assembly diagram of the driving component in a hopping wheeled mobile robot proposed in this invention.
[0019] In the diagram: 1. Body; 2. Jump motor; 3. Thigh linkage; 4. Lower leg linkage; 5. Plug screw; 6. Flange bearing; 7. Washer; 8. Torsion spring; 9. Motor mounting bracket; 10. Ball bearing; 1001. Bearing retaining ring; 11. Travel motor; 12. Connecting bracket; 13. Wheel mounting bracket; 14. Mecanum wheel; 15. Limit ring. Detailed Implementation
[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0021] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0022] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" 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 a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0023] Example, refer to Figures 1 to 7 A hopping wheeled mobile robot includes a body 1, four hopping motors 2 on both sides of the body 1, the output end of the hopping motors 2 is connected to an adaptive shock-absorbing leg, and a driving component is provided on the side of the adaptive shock-absorbing leg away from the body 1. The adaptive shock-absorbing leg includes a thigh link 3, a lower leg link 4, and a rotating joint. The upper end of the thigh link 3 is connected to the corresponding jump motor 2, and the lower end of the thigh link 3 is connected to the upper end of the lower leg link 4 through the rotating joint. The rotating joint includes a plug screw 5, a flange bearing 6, a washer 7, and a torsion spring 8. The plug screw 5 passes through the flange bearing 6, the thigh link 3, the washer 7, the torsion spring 8, and the lower leg link 4 in sequence, and hinges the thigh link 3 and the lower leg link 4. The travel assembly includes a motor mounting base 9, with a ball bearing 10 on the outer side wall of the motor mounting base 9 and a bearing retaining ring 1001 on the outer side wall of the ball bearing 10. A travel motor 11 is embedded in the motor mounting base 9. A connecting seat 12 is provided on the side of the motor mounting base 9 away from the body 1. A wheel mounting seat 13 is rotatably connected in the connecting seat 12. One end of the wheel mounting seat 13 is connected to the output end of the travel motor 11, and a Mecanum wheel 14 is fixedly installed at the other end of the wheel mounting seat 13.
[0024] Furthermore, the two ends of the torsion spring 8 are respectively fixed to the middle of the thigh link 3 and the middle of the lower leg link 4, which are used to absorb impact energy and assist the leg in recovery when jumping and landing; Furthermore, the restoring torque and energy absorption of the torsion spring 8 are calculated according to the following formula: In the formula: The restoring torque generated by torsion spring 8 The torsional stiffness of the torsion spring 8 is set in the range of 3.8 N·m / rad to 25.6 N·m / rad. The impact kinetic energy absorbed by the torsion spring 8 The torsion angle of the torsion spring 8 is set in the range of π / 6 (30°) to π / 2 (90°). The further advantage of adopting the above is that by establishing a quantitative relationship between jump height, acceleration time, and takeoff speed, the motor control parameters can be calculated in reverse according to the actual obstacle crossing requirements, so as to achieve precise planning and repeated execution of the jump action and avoid energy waste or insufficient jump height caused by blind acceleration.
[0025] Furthermore, the formulas for calculating the robot's ground clearance speed and jump height during the jump are as follows: In the formula: The instantaneous velocity upon takeoff is 1.5 m / s, corresponding to an instantaneous velocity upon takeoff of approximately 1.401 m / s. The acceleration generated by the jump motor drive, To speed up the process, The target value for the jump height is 0.1m. The acceleration due to gravity is taken as 9.81 m / s². 2 , For the time required to clear the space.
[0026] Furthermore, the relationship between the landing impact force and the deformation of the torsion spring 8 is as follows: In the formula: For the impact force during landing, The damping coefficient of torsion spring 8, For a torsion spring with a torsion angle of 8, The torsional angle change rate is used to characterize the instantaneous velocity of the impact. The torsional angle change rate of this robot during landing is approximately 42 rad / s. The further advantage of adopting the above is that by introducing a damping term to characterize the influence of impact velocity on dynamic force, the transient impact characteristics at the moment of landing can be described more accurately, providing theoretical guidance for the material selection and damping coefficient optimization of the torsion spring 8, and ensuring that peak reduction can still be effectively achieved under high-speed landing conditions.
[0027] Furthermore, the two lower leg connecting rods 4 located on the same side of the body 1 are respectively fixed to both sides of the same bearing retaining ring 1001, so that the wheel foot structure and the shock absorption system are integrated in a mechanical way, eliminating the need for separate shock absorber mounting seats and connecting parts. While reducing the weight of the whole machine and structural redundancy, the symmetry and consistency of the buffer response of the left and right legs are ensured. Furthermore, limit rings 15 are fixedly installed on both sides of the body 1 corresponding to the jump motor 2. The limit rings 15 are sleeved on the outer periphery of the output shaft of the jump motor 2 to limit the swing angle range of the thigh connecting rod 3 relative to the body 1. Furthermore, the active attitude control employs a PID control algorithm to achieve closed-loop adjustment of the fuselage attitude, and its core control formula is as follows: In the formula: The output control quantity for jump motor 2, is the proportionality coefficient, ranging from 1.8 to 2.2; Ki is the integral coefficient. These are the differential coefficients, ranging from 0.5 to 0.7. for Constant deviation in fuselage attitude, As an integral variable, the output speed and torque of the jump motor 2 are adjusted in real time using this formula to ensure the stability of the fuselage attitude; The further advantage of adopting the above is that, through the coordinated adjustment of the proportional, integral, and derivative components, the pitch and roll deviations of the fuselage can be quickly responded to and steadily eliminated during takeoff. Combined with the calibrated optimal coefficient range, high dynamic response and zero steady-state error control for attitude correction are achieved, ensuring that the wheeled structure always lands downwards in the predetermined attitude.
[0028] When the robot is in use, performing baggage transfer or inspection tasks on a flat airport runway, the active attitude control system detects the attitude of the robot 1 in real time through an inertial measurement unit fixed at the geometric center of the robot body 1. The controller controls the four jump motors 2 according to the attitude signals, so that the four adaptive shock-absorbing legs maintain a certain pre-compression angle. The travel motor 11 in the travel assembly drives the Mecanum wheel 14 to rotate, realizing omnidirectional high-speed movement. During this process, the torsion spring 8 is in a small-angle deformation state, according to the restoring torque formula. The torsion spring 8 generates a restoring torque proportional to the torsion angle, which is used to filter out high-frequency micro-vibrations on the ground and ensure the smooth operation of the machine body 1.
[0029] When the robot encounters steps, wheel stops, or needs to cross obstacles, the controller issues a jump command. The jump motor 2 quickly drives the thigh link 3 to swing forward, while the lower leg link 4 extends with the help of inertia and torsion spring 8, giving the robot an upward acceleration and enabling it to jump off the ground. According to the jump height formula, by controlling the motor acceleration time and acceleration, the target jump height can be achieved to cross ground obstacles.
[0030] During the jump and takeoff phase, the pitch and roll angles of the robot body 1 are detected in real time using the inertial measurement unit in the existing technology. The controller fine-tunes the output of each jump motor 2 according to the attitude deviation signal through the PID control algorithm. The output speed and torque of the motor are adjusted in real time according to the PID control formula to correct the robot's attitude in the air and ensure that the wheeled mobile structure is facing down in preparation for landing.
[0031] At the moment of landing, the wheeled moving structure makes contact with the ground first. The impact force is transmitted to the rotating joint through the lower leg link 4, forcing the lower leg link 4 to fold upward relative to the thigh link 3. The torsion spring 8 is then twisted sharply, according to the energy absorption formula. This converts impact kinetic energy into elastic potential energy, achieving graded energy absorption, based on the landing impact force formula. The torsional stiffness of the torsion spring 8 is used to resist deformation, and the damping coefficient is used to dissipate impact energy. Together, they effectively reduce the peak impact value.
[0032] Under the reaction force of the torsion spring 8, the lower leg link 4 slowly returns to its original position. According to the restoring torque formula, the torsion spring 8 releases part of the stored elastic potential energy to help the robot restore its standing posture. The limiting ring 15 is sleeved on the outer periphery of the output shaft of the jump motor 2 to limit the swing angle range of the thigh link 3 relative to the body 1 and avoid mechanism interference. The entire shock absorption process is completed passively, with fast response speed and high reliability. The robot can quickly return to the wheeled movement mode and continue to perform subsequent tasks.
[0033] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
Claims
1. A hopping wheeled mobile robot, comprising a body (1) and an active posture control system, characterized in that, The body (1) has four jumping motors (2) on both sides. The output end of the jumping motor (2) is connected to an adaptive shock-absorbing leg. The adaptive shock-absorbing leg is provided with a travel component on the side away from the body (1). The adaptive shock-absorbing leg includes a thigh link (3), a lower leg link (4) and a rotating joint. The upper end of the thigh link (3) is connected to the corresponding jump motor (2), and the lower end of the thigh link (3) is connected to the upper end of the lower leg link (4) through the rotating joint. The rotating joint includes a plug screw (5), a flange bearing (6), a washer (7) and a torsion spring (8). The plug screw (5) passes through the flange bearing (6), the thigh link (3), the washer (7), the torsion spring (8) and the lower leg link (4) in sequence, and hinges the thigh link (3) and the lower leg link (4). The driving assembly includes a motor mounting base (9), a ball bearing (10) is provided on the outer side wall of the motor mounting base (9), a bearing retainer (1001) is provided on the outer side wall of the ball bearing (10), a driving motor (11) is embedded in the motor mounting base (9), a connecting seat (12) is provided on the side of the motor mounting base (9) away from the body (1), a wheel mounting base (13) is rotatably connected in the connecting seat (12), one end of the wheel mounting base (13) is connected to the output end of the driving motor (11), and a Mecanum wheel (14) is fixedly installed on the other end of the wheel mounting base (13).
2. The hopping wheel-legged mobile robot according to claim 1, characterized in that, The two ends of the torsion spring (8) are fixed to the middle of the thigh link (3) and the middle of the lower leg link (4) respectively, and are used to absorb impact energy and assist the leg to return to its original position when jumping and landing.
3. The hopping wheel-legged mobile robot according to claim 2, characterized in that, The restoring torque and energy absorption of the torsion spring (8) are calculated according to the following formula: In the formula: The restoring torque generated by the torsion spring (8), For the torsional stiffness of the torsion spring (8), The impact kinetic energy absorbed by the torsion spring (8) The torsion angle of the torsion spring (8).
4. The hopping wheel-legged mobile robot according to claim 1, characterized in that, The formulas for calculating the robot's takeoff speed and jump height during the jump are as follows: In the formula: The instantaneous velocity of the robot when it leaves the ground. The acceleration generated by the jump motor (2) To speed up the process, For jump height, This is the acceleration due to gravity.
5. A hopping wheel-legged mobile robot according to claim 3, characterized in that, The relationship between the landing impact force and the deformation of the torsion spring (8) is as follows: In the formula: For the impact force during landing, The damping coefficient of the torsion spring (8); For the torsion angle of the torsion spring (8), This represents the rate of change of the torsion angle.
6. A hopping wheel-legged mobile robot according to claim 1, characterized in that, The two lower leg connecting rods (4) located on the same side of the body (1) are respectively fixed on both sides of the same bearing retaining ring (1001).
7. A hopping wheel-legged mobile robot according to claim 1, characterized in that, Limiting rings (15) are fixedly installed on both sides of the body (1) at the jump motor (2). The limiting rings (15) are sleeved on the outer periphery of the output shaft of the jump motor (2) to limit the swing angle range of the thigh link (3) relative to the body (1).
8. A hopping wheel-legged mobile robot according to claim 1, characterized in that, The active attitude control employs a PID control algorithm to achieve closed-loop adjustment of the fuselage attitude. Its core control formula is as follows: In the formula: The output control quantity for the jump motor; This is the proportionality coefficient; The integral coefficient is... These are the differential coefficients. for Constant deviation in fuselage attitude, As an integral variable, the output speed and torque of the jump motor (2) are adjusted in real time through this formula to ensure the stability of the body posture.