A motion control system for a bionic leg-type landing gear

Abstract

The present application belongs to the field of landing gear for vertical take-off and landing aircraft, and is a bionic leg-type landing gear motion control system, comprising a navigation layer, a planning layer, a control layer and a structural layer; when the aircraft is preparing to land, it first collects external environment data through a laser radar and a visual camera, and then the navigation layer performs comprehensive analysis and processing based on the outer ring environment data and motion instruction data to generate a decision instruction; then the planning layer solves the behavioral parameters of the control decision, and makes a posture adjustment instruction based on the slope terrain information and the leg posture information; the control layer generates a driving instruction for the motion parameters of each joint based on the posture adjustment instruction and a single-leg model; the structural layer drives each joint to move based on the motion parameter driving instruction, and interacts with the slope terrain environment in real time, so that during landing, no matter what kind of inclined terrain, the bionic leg can control the foot force corresponding to the joint angle, thereby achieving a stable landing of the aircraft on the terrain.

Description

Technical Field

[0001] The present application belongs to the field of vertical take-off and landing aircraft landing gear, and in particular relates to a bionic leg-type landing gear motion control system. Background Art

[0002] Conventional unmanned helicopters currently use two common landing gear types: skid-type and wheel-type. Their takeoff and landing environment should be as flat as possible, the descent should be slow and smooth, and the entire aircraft should remain stable after landing. However, for certain applications, flat areas are not easy to find, and suitable takeoff and landing locations are often difficult to find in field land combat environments, such as hilly terrain and rocky ground. Furthermore, in marine environments, strong winds and waves can cause deck swaying, which can adversely affect the safe takeoff, landing, and parking of unmanned helicopters. These restrictions significantly limit the applicability of unmanned helicopters.

[0003] An existing aircraft landing navigation system and control method utilizes a laser receiving unit, an aircraft GPS unit, an aircraft control unit, and an aircraft communication unit. The system uses lasers to guide the aircraft and adjust its position. The laser receiving unit automatically receives the laser signal, locates the aircraft's descent position, and achieves a positioned landing. This design only enables positioned landing and is incapable of adapting to complex, unstructured terrain.

[0004] Prior art also discloses an autonomous control method for pinpoint landing of a shipborne aircraft. This system uses an altitude-guided control method to track the altitude trajectory to achieve pinpoint landing of the shipborne aircraft. However, this design only enables pinpoint landing on the ship's surface, making it difficult for the shipborne aircraft to achieve autonomous and stable landing in complex sea conditions.

[0005] Therefore, how to achieve autonomous and stable landing in complex and unstructured terrain is a problem that needs to be solved. Summary of the Invention

[0006] The purpose of this application is to provide a bionic leg-type landing gear motion control system to solve the problem that existing aircraft are difficult to adapt to various unstructured terrains and complex sea conditions in the field and have difficulty landing due to shaking ship decks.

[0007] The technical solution of the present application is: a bionic leg-type landing gear motion control system, including a navigation layer, a planning layer, a control layer and a structural layer; the navigation layer includes an environment sensing module, a data processing module and a decision instruction module; the environment sensing module is used to generate a two-dimensional image of a visual camera through visual camera scanning, form a three-dimensional point cloud of the laser radar through a laser radar, and send it to the data processing module; the data processing module is used to model the terrain environment based on the data of the two-dimensional image of the visual camera and the three-dimensional point cloud of the laser radar, form a terrain environment model, and send it to the decision instruction module; the decision instruction module is used to make a decision on the landing point based on the terrain environment model and the motion instruction data issued by the host computer, and send the decision instruction to the planning layer; the planning layer includes a behavior parameter solving module, a terrain information parsing module and a posture adjustment module; the behavior parameter solving module is used to parse the decision instruction, generate relevant terrain information and the position information of the landing point; the terrain information parsing module is used to parse the relevant information information, generate a specific The terrain parameters of the body are calculated, and the posture adjustment module is used to plan the landing posture and contact force of each leg of the bionic leg according to the specific terrain parameters, generate posture adjustment instructions, and send them to the control layer; the control layer includes a single-leg model management module and a single-leg model, and the single-leg model has multiple groups and generates different single-leg models according to different legs of the bionic leg. The single-leg model management module is used to receive the landing posture and contact force of each leg, and send them to each single-leg model respectively. The single-leg model determines the control amount of each joint of the leg according to the specific landing posture and contact force, generates a joint motion parameter driving instruction, and sends it to the structural layer; the structural layer includes a single-leg structure management module and a single-leg structure unit. The single-leg structure management module is used to receive different joint motion parameter driving instructions of different legs, and send them to different single-leg structure units. The single-leg structure unit obtains the motion parameters of each joint motor according to the specific joint motion parameter driving instruction, and outputs the motor shaft torque to drive the joint rotation.

[0008] Preferably, a speed planning module is also provided in the navigation layer, and the speed planning module is used to generate three stages from high to low according to the current aircraft altitude and the distance from the target point. In the first stage, the aircraft is controlled to land at a higher speed, and in the second stage, the aircraft is controlled to land at a lower speed. The speed of the aircraft in the first stage is greater than the speed of the aircraft in the second stage. In the third stage, the foot touches the ground to control the aircraft to hover.

[0009] Preferably, the posture adjustment module uses a foot force distribution algorithm combined with impedance control to calculate the expected foot force values for different legs, and performs foot force distribution, landing control, joint space control, joint angle planning, leg angle solution and posture planning.

[0010] Preferably, the single-leg model includes a computational model and a dynamic model. The computational model calculates the change in driving joint angle caused by the change in foot end position, and the dynamic model calculates the control amount of each joint of the bionic leg in the joint space, and uses impedance control to adjust the corresponding foot force to generate foot force distribution information.

[0011] Preferably, the single-leg structural unit is provided with a torque sensor and an accelerometer. The torque sensor detects the joint torque in real time, and the accelerometer detects the pitch, yaw and roll angles of the fuselage. The torque sensor and accelerometer send the monitored data to the single-leg model. The single-leg model dynamically plans the foot force distribution information according to the changes in the joint torque and the pitch, yaw and roll angles of the fuselage, and generates a new landing posture and contact force through impedance control, and sends it to the single-leg structural unit again to control the corresponding single leg.

[0012] The present application discloses a bionic leg-type landing gear motion control system, comprising a navigation layer, a planning layer, a control layer and a structural layer. When the aircraft is preparing to land, external environment data is first collected through a laser radar and a visual camera. Then, the navigation layer performs comprehensive analysis and processing based on the outer ring environment data and motion instruction data to generate a decision instruction. Then, the planning layer solves the behavioral parameters of the control decision, and makes a posture adjustment instruction based on the slope terrain information and the leg posture information. The control layer generates a motion parameter driving instruction for each joint based on the posture adjustment instruction and a single-leg model. The structural layer drives each joint to move based on the motion parameter driving instruction, and interacts with the slope terrain environment in real time. In this way, no matter what kind of inclined terrain is encountered during landing, the bionic leg can achieve a stable landing of the aircraft on the terrain by controlling the foot force at the corresponding angle of the joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions provided by this application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this application.

[0014] Figure 1 This is a schematic diagram of the overall structure of this application. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solutions and advantages of the implementation of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below in conjunction with the drawings in the embodiments of this application.

[0016] A bionic leg-type landing gear motion control system, such as Figure 1 As shown, it includes navigation layer, planning layer, control layer and structure layer.

[0017] The navigation layer includes an environment sensing module, a data processing module and a decision-making instruction module; the environment sensing module is used to generate a two-dimensional image of the visual camera through scanning with a visual camera, form a three-dimensional point cloud of the lidar through a lidar, and send it to the data processing module; the data processing module is used to model the terrain environment based on the data of the two-dimensional image of the visual camera and the three-dimensional point cloud of the lidar, form a terrain environment model, and send it to the decision-making instruction module; the decision-making instruction module is used to make a decision on the landing point based on the terrain environment model and the motion instruction data issued by the host computer, and send the decision instruction to the planning layer.

[0018] The planning layer includes a behavior parameter calculation module, a terrain information analysis module and a posture adjustment module; the behavior parameter calculation module is used to analyze decision instructions and generate relevant terrain information and the location information of the landing point; the terrain information analysis module is used to analyze relevant information and generate specific terrain parameters; the posture adjustment module is used to plan the landing posture and contact force of each leg of the bionic leg according to the specific terrain parameters, generate posture adjustment instructions, and send them to the control layer.

[0019] The control layer includes a single-leg model management module and a single-leg model. The single-leg model has multiple groups and generates different single-leg models according to the different single legs of the bionic leg. The single-leg model management module is used to receive the landing posture and contact force of each leg, and send them to each single-leg model respectively. The single-leg model determines the control amount of each joint of the single leg according to the specific landing posture and contact force, generates joint motion parameter drive instructions, and sends them to the structural layer.

[0020] The structural layer includes a single-leg structure management module and a single-leg structure unit. The single-leg structure management module is used to receive different joint motion parameter driving instructions of different legs and send them to different single-leg structure units. The single-leg structure unit obtains the motion parameters of each joint motor according to the specific joint motion parameter driving instructions, and outputs the motor shaft torque to drive the joint rotation.

[0021] When the aircraft is preparing to land, it first collects external environment data through lidar and visual cameras, and then the navigation layer conducts comprehensive analysis and processing based on the outer ring environment data and motion instruction data to generate decision instructions; then the planning layer solves the behavioral parameters of the control decision, and makes posture adjustment instructions based on the slope terrain information and leg posture information. The control layer generates motion parameter driving instructions for each joint based on the posture adjustment instructions and the single-leg model. The structural layer drives each joint to move according to the motion parameter driving instructions, and interacts with the slope terrain environment in real time. In this way, no matter what kind of inclined terrain is during landing, the bionic leg can control the foot force at the corresponding angle of the joint, so as to achieve a stable landing of the aircraft on the terrain.

[0022] This application integrates flight control, environmental perception, and leg mechanism control data, determines and selects a suitable landing terrain through the environmental perception system, and guides the leg posture to pre-swing before landing, thereby improving terrain adaptability and achieving stable landing in various unstructured terrains and complex sea conditions with shaking ship surfaces in the wild.

[0023] Preferably, a speed planning module is also provided in the navigation layer. The speed planning module is used to generate three stages from high to low according to the current aircraft height and the distance from the target point. In the first stage, the aircraft is controlled to land at a higher speed. In the second stage, the aircraft is controlled to land at a lower speed. For example, when the vertical height from the target point is less than 20m, the aircraft continues to descend vertically at a lower speed. The speed of the aircraft in the first stage is greater than the speed of the aircraft in the second stage. In the third stage, the foot touches the ground, that is, the foot force sensor is not zero, and the aircraft is controlled to hover, and the leg impedance control is turned on to eliminate errors and interference, so that all the foot ends gradually touch the ground in a smooth manner.

[0024] The posture adjustment module preferably uses a force distribution algorithm combined with impedance control to calculate the desired force values for each leg, thereby maintaining body stability and reducing excessive weight on a single leg. It also performs force distribution, landing control, joint space control, joint angle planning, leg angle calculation, and posture planning to ensure that the body completes posture adjustment during the low-speed descent phase and completes the predetermined joint space trajectory before the foot touches the ground.

[0025] The terrain information analysis module can analyze the terrain information of flat terrain, slope terrain, step terrain and shaking ship surface respectively, and generate different terrain parameters.

[0026] Preferably, the single-leg model includes a computational model and a dynamic model. The computational model calculates the change in the driving joint angle caused by the change in the foot end position. The dynamic model calculates the control amount of each joint of the bionic leg in the joint space, and uses impedance control to adjust the corresponding foot force, generate foot force distribution information, and realize the adjustment of the body's posture after landing.

[0027] Preferably, the single-leg structural unit is equipped with a torque sensor and accelerometer. The torque sensor detects joint torque in real time, while the accelerometer detects the pitch, yaw, and roll angles of the aircraft. The torque sensor and accelerometer transmit the monitored data to the single-leg model. The single-leg model dynamically plans the distribution of foot force based on the changes in joint torque and the pitch, yaw, and roll angles of the aircraft. It then generates a new landing posture and contact force through impedance control, and transmits this information back to the single-leg structural unit to control the corresponding leg. By providing a torque sensor and accelerometer, the landing posture of each leg can be further corrected, resulting in a more stable landing for the aircraft.

[0028] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A bionic leg-type landing gear motion control system, characterized by: Includes navigation layer, planning layer, control layer and structure layer; The navigation layer includes an environment sensing module, a data processing module, and a decision-making instruction module; the environment sensing module is used to generate a two-dimensional image of the visual camera through scanning with a visual camera, and to form a three-dimensional point cloud of the laser radar through a laser radar, and send the result to the data processing module; the data processing module is used to perform terrain environment modeling based on the data of the two-dimensional image of the visual camera and the three-dimensional point cloud of the laser radar, form a terrain environment model, and send the result to the decision-making instruction module; the decision-making instruction module is used to make a landing point decision based on the terrain environment model and the motion instruction data issued by the host computer, and send the decision instruction to the planning layer; The planning layer includes a behavior parameter calculation module, a terrain information analysis module, and a posture adjustment module; the behavior parameter calculation module is used to analyze decision instructions and generate relevant terrain information and landing point location information; the terrain information analysis module is used to analyze relevant information and generate specific terrain parameters; the posture adjustment module is used to plan the landing posture and contact force of each leg of the bionic leg according to the specific terrain parameters, generate posture adjustment instructions, and send them to the control layer; The control layer includes a single-leg model management module and a single-leg model. The single-leg model has multiple groups and generates different single-leg models according to different single legs of the bionic leg. The single-leg model management module is used to receive the landing posture and contact force of each leg and send them to each single-leg model respectively. The single-leg model determines the control amount of each joint of the single leg according to the specific landing posture and contact force, generates joint motion parameter drive instructions, and sends them to the structural layer; The structural layer includes a single-leg structure management module and a single-leg structure unit. The single-leg structure management module is used to receive different joint motion parameter drive instructions for different legs and send them to different single-leg structure units. The single-leg structure unit obtains the motion parameters of each joint motor according to the specific joint motion parameter drive instructions and outputs the motor shaft torque to drive the joint rotation. The navigation layer is also provided with a speed planning module, which is used to generate three stages from high to low according to the current aircraft altitude and the distance between the target point. In the first stage, the aircraft is controlled to land at a higher speed, and in the second stage, the aircraft is controlled to land at a lower speed. The speed of the aircraft in the first stage is greater than the speed of the aircraft in the second stage. In the third stage, the foot touches the ground to control the aircraft to hover.

2. The bionic leg-type landing gear motion control system according to claim 1, characterized in that: The posture adjustment module uses a foot force distribution algorithm combined with impedance control to calculate the expected foot force values for different legs, and performs foot force distribution, landing control, joint space control, joint angle planning, leg angle solution and posture planning.

3. The bionic leg-type landing gear motion control system according to claim 1, characterized in that: The single-leg model includes a computational model and a dynamic model. The computational model calculates the change in the driving joint angle caused by the change in the foot end position. The dynamic model calculates the control amount of each joint of the bionic leg in the joint space, and uses impedance control to adjust the corresponding foot force to generate foot force distribution information.

4. The bionic leg-type landing gear motion control system according to claim 3, characterized in that: The single-leg structural unit is provided with a torque sensor and an accelerometer. The torque sensor detects the joint torque in real time, and the accelerometer detects the pitch, yaw and roll angles of the fuselage. The torque sensor and accelerometer send the monitored data to the single-leg model. The single-leg model dynamically plans the foot force distribution information according to the changes in the joint torque and the pitch, yaw and roll angles of the fuselage, and generates a new landing posture and contact force through impedance control, and sends it to the single-leg structural unit again to control the corresponding single leg.

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