Haitao Yang

Bio: Haitao Yang is an academic researcher from Harbin Institute of Technology. The author has contributed to research in topics: Robot & Visual servoing. The author has an hindex of 6, co-authored 16 publications receiving 87 citations.

Capture tolerance capacity testing system and method of three-jaw type space end effector in microgravity environment

Abstract: The invention discloses a capture tolerance capacity testing system and method of a three-jaw type space end effector in a microgravity environment, and relates to a target interface capture tolerance capacity testing system and method of a three-jaw type space manipulator end effector in the microgravity environment. The problems that an existing microgravity platform verification system is complex, poor in safety and reliability and not capable of achieving six-degree-of-freedom motion of a mechanical arm or a spacecraft in the three-dimensional space of the microgravity environment can be solved. The capture tolerance capacity testing system comprises a capture subsystem, a target subsystem and a measurement subsystem. The capture tolerance capacity testing method includes the steps that first, the capture tolerance capacity testing system is mounted; second, the original position and the coordinate axis of a coordinate system of the space end effector are determined; third, the pose of the three-jaw type space end effector is determined; fourth, the pose of a target to be captured is determined; fifth, the pose deviation of the target to be captured relative to the space end effector is acquired; sixth, a capture test is carried out under different pose deviations. The capture tolerance capacity testing system and method of the three-jaw type space end effector in the microgravity environment belong to the field of space robots or spacecraft ground verification systems.

Ground verification of space robot capturing the free-floating target based on visual servoing control with time delay

Abstract: Purpose – The purpose of this paper is to solve the ground verification and test method for space robot system capturing the target satellite based on visual servoing with time-delay in 3-dimensional space prior to space robot being launched. Design/methodology/approach – To implement the approaching and capturing task, a motion planning method for visual servoing the space manipulator to capture a moving target is presented. This is mainly used to solve the time-delay problem of the visual servoing control system and the motion uncertainty of the target satellite. To verify and test the feasibility and reliability of the method in three-dimensional (3D) operating space, a set of ground hardware-in-the-loop simulation verification systems is developed, which adopts the end-tip kinematics equivalence and dynamics simulation method. Findings – The results of the ground hardware-in-the-loop simulation experiment validate the reliability of the eye-in-hand visual system in the 3D operating space and prove the...

Device and method for simulating space mechanical arm to capture ground three-dimensional space microgravity of target satellite

Abstract: The invention provides a device and method for simulating a space mechanical arm to capture ground three-dimensional space microgravity of a target satellite, and relates to a device and method of the ground three-dimensional space microgravity. The problem that the movement of a floating satellite base in the three-dimensional space and operation process of the space mechanical arm is not considered is solved. The device comprises two industrial mechanical arms, the space mechanical arm, a hand eye camera, a capturing paw, a capturing connector, a service satellite body simulator, a target satellite body simulator and six-dimensional force and torque sensors; the method comprises the steps that target satellite movement is simulated; the position and attitude of the target satellite and movement information of joints of the space mechanical arm are determined; movement information of a service satellite body simulator base and the industrial mechanism arms is calculated; the capturing connector captures the target satellite body simulator in a capturing paw area; a movement state of the service satellite body simulator is achieved by simulating a real target satellite movement sate. The device and method for simulating the space mechanical arm to capture the ground three-dimensional space microgravity of the target satellite is applied to the field of space mechanical arm ground three-dimensional space microgravity simulation.

Development of ground experiment system for space end-effector capturing the floating target in 3-dimensional space

Abstract: Purpose – The purpose of this paper is to develop a set of ground experiment system to verify the basic functions of space effector and the capturing reliability of space end-effector for the free-floating target payload in the three-dimensional space. The development of ground experiment system for space end-effector is essential and significant, because it costs too much to launch a space robot or other spacecraft and carry out operation tasks in space. Owing to the negligible gravity in space, which is different from that in the ground environment, ground experiment system for space end-effector should have the capability of verifying the basic functions of space effector and the reliability of space end-effector in capturing the free-floating target payload in space. Design/methodology/approach – The ground experiment system for space end-effector mainly adopts the hybrid simulation method, which includes the real hardware experiment and software simulation. To emulate the micro-gravity environment, t...

Minimum Base Disturbance Control of Free-Floating Space Robot during Visual Servoing Pre-capturing Process

Abstract: During visual servoing space activities, the attitude of free-floating space robot may be disturbed due to dynamics coupling between the satellite base and the manipulator. And the disturbance may cause communication interruption between space robot and control center on earth. However, it often happens that the redundancy of manipulator is not enough to fully eliminate this disturbance. In this paper, a method named off-line optimizing visual servoing algorithm is innovatively proposed to minimize the base disturbance during the visual servoing process where the degrees-of-freedom of the manipulator is not enough for a zero-reaction control. Based on the characteristic of visual servoing process and the robot system modeling, the optimal control method is applied to achieve the optimization, and a pose planning method is presented to achieve a second-order continuity of quaternion getting rid of the interruption caused by ambiguity. Then simulations are carried out to verify the method, and the results show that the robot is controlled with optimized results during visual servoing process and the joint trajectories are smooth.

Direct image-based visual servoing of free-floating space manipulators

Abstract: This paper presents an image-based controller to perform the guidance of a free-floating robot manipulator. The manipulator has an eye-in-hand camera system, and is attached to a base satellite. The base is completely free and floating in space with no attitude control, and thus, freely reacting to the movements of the robot manipulator attached to it. The proposed image-based approach uses the system's kinematics and dynamics model, not only to achieve a desired location with respect to an observed object in space, but also to follow a desired trajectory with respect to the object. To do this, the paper presents an optimal control approach to guiding the free-floating satellite-mounted robot, using visual information and considering the optimization of the motor commands with respect to a specified metric along with chaos compensation. The proposed controller is applied to the visual control of a four-degree-of-freedom robot manipulator in different scenarios.

A High-Gain Transmitarray for Generating Dual-Mode OAM Beams

Abstract: This paper proposes a novel transmitarray antenna which can achieve high gain and produce dual-mode orbital angular momentum (OAM) beams in Ku -band. Two back-to-back wideband dual-polarized microstrip antennas are employed as the unit cells, which are connected using metalized via holes. Full 360° phase ranges can be obtained by varying the length of feeding lines in two orthogonal polarizations. Due to high isolation between the two orthogonal polarizations, dual-mode OAM beams can be formed simultaneously by tuning phase distributions in x- and y-polarizations, respectively. The approach for generating OAM beams is explained. To verify this concept, one prototype carrying 0 and +1 mode OAM beams is designed, fabricated, and measured. Experimental results demonstrate that both 0 and +1 mode OAM beams can be generated successfully, and the measured results agree well with the simulated results. Because of high directivity and focusing effects of transmitarray, the proposed +1 mode OAM beam has stable performance at a long propagation distance. The maximum gain reaches 26 and 20 dBi in 0 and +1 mode OAM beams, respectively. Meanwhile, a narrow divergence angle of ±5° is obtained in +1 mode OAM beam. Compared with other OAM antennas reported, main advantages of the proposed antenna include high gain, narrow divergence angle, low cost, planar structure, and the capability of producing dual-mode OAM beams.

Compensation of base disturbance using optimal trajectory planning of dual-manipulators in a space robot

Abstract: This paper presents a trajectory planning algorithm for a space robot with dual-manipulators. Here one manipulator of the space robot captures a target, and another manipulator is free. In this case, this study uses one manipulator as the mission manipulator to capture the target, and another as the balance manipulator aiming at the compensation of the pose disturbance. For this method, a novel trajectory planning algorithm applied to the balance manipulator is presented. The trajectory planning problem is transformed into series of problems of the optimal state solution, and then the iterative algorithms for the trajectory planning are designed. In the iterative algorithms, the bias force on the spacecraft base caused by the balance manipulator is used as the compensation force. Then, to calculate the expected compensation force and torque, a pose control law for the spacecraft base is introduced. The expected compensation force and torque provide equality constraints for optimization problems, which implies that the trajectory planning algorithm compensates for not only the disturbance generated by the manipulator’s motion, but also environmental disturbances. This is because the expected compensation force and torque depend on the pose change of the spacecraft base rather than the type of the disturbance. Numerical simulation was carried out to analyze the proposed trajectory planning method. It was observed that the method greatly reduces the disturbance of Manipulator A on the spacecraft base. These results validated the effectiveness of the proposed method for the trajectory planning to make the spacecraft base disturbance up to minimum.

Teleoperation method and system for grabbing objects using space mechanical arm based on simulation

Abstract: The invention provides a teleoperation system for grabbing objects using space mechanical arm based on simulation, which comprises a data source acquisition module, a middle piece module, a target tracking and positioning module, an operation planning module, and a motion simulation module. Through an insertion piece type structuring strategy, it is possible to realize the real time acquisition of a plurality of different data sources by the system and to realize the inconsistency adjustment between data acquisition and data processing speed. Through the use of a rapid tracking algorithm, the photographing camera is ensured to track the target in real time; and through the pose measurement algorithm, the synchronization of the poses between a real target and a simulated target could be ensured. The invention provides a testing platform for the visual positioning algorithm in the dynamic target grabbing process by a space mechanism arm and can demonstrate the grabbing process through a three-dimensional visualized manner to assist the operation men on the ground to complete the control over the grabbing process.