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This paper presents a novel way to derive the analytical expression of the reaction torque acted on the satellite base's centroid firstly. The reaction torque is acted as the optimization index to achieve the satellite base disturbance minimization in this paper. The null-space based solution and Lagrange multipliers based solution are utilized to solve the reaction torque plus joint torque minimization...
In this paper, a novel robust adaptive controller is proposed to simultaneously cope with the unknown nonlinear backlash, friction and dynamic uncertainties in the 3-DOF robotic head system. Inverse backlash compensation with on-line backlash parameter estimation and model-based friction compensation with off-line Stribeck friction identification are incorporated into this robust adaptive scheme....
Around 2020, China is going to build its own space station and to carry out space science research of larger scale. Chinese Space Station (CSS) will operate in orbit for about ten years. This period will provide much more opportunities to scientists in China after the international space station. The space manipulators as cost-effective, energy-efficient tools supporting humans on extended space missions...
Manipulators with flexible joints are widely used as the space manipulators, whereas the elasticity of flexible joint leads to poor dynamic performance. To solve the influence of elasticity, the paper is to establish the model of flexible joint, identify the parameters, and design the controller. The off-line methods are applied to identify the current coefficient and the parameters of flexible joint...
The traditional six-dimensional force/torque sensor calibration method requires a lot of precision loading force and can only be off-line calibration. In this paper, to solve the problem, an online calibration and decoupling method based on the shape from motion combined with complex algorithm is proposed. It does not require accurate and redundant loading force information, and have better noise...
In order to achieve large tolerance capture and high stiffness connection for space payload operations, a Chinese large-scale space end-effector (EER) was developed. Friction is a kind of strong nonlinear factor that severely degrades performance of EER. To predict the friction amplitude and compensate the dynamic error, the friction model based Generalized Maxwell-Slip model (GMS) is built. In order...
A space-saving end-effector is designed for small scale manipulator in this paper. The end-effector is equipped with capture and actuation transmission capabilities. Two subsystems are highly integrated systems of mechanics, electronics and sensors. A trefoil shaped capture system is developed for closed envelop. The worm shaft and worm wheels are adopted for the self-locking property, and they are...
This paper proposes the design and development of an integrated serial elastic actuator (SEA) which is used as the elbow joint in the soft humanoid arm. First, requirements of SEA are illustrated. And six different types of elastic elements (e.g. the discoid element, the cylindrical) are analyzed using the design of experiment (DOE) method. And then, a discoid elastic element with larger flexibility...
Not only output of the six-dimension force/torque sensor changes with force or torque, but also be susceptible to ambient temperature, thus limiting measurement accuracy of the sensor. In order to overcome the above drawbacks of six-dimension force/torque sensor, this paper proposes a temperature compensation method based on Radial Basis Function (RBF) Neural Network. Compared with the conventional...
This paper presents a novel six-axis force/torque sensor based on strain gauges. Firstly, the six-axis force/torque sensor's design criterion is systematically expounded by calibration matrix, condition number, coupling error, sensor accuracy, strain gauge sensitivity, sensor sensitivity and sensor stiffness. Secondly, a novel sensing element is designed and simulated by finite element method. Then,...
A highly integrated joint controller using in a humanoid robot arm has been developed in the paper. The joint controller is highly integrated with position sensors — the hall sensors, the magnetic sensor and the photoelectrical sensor, the torque sensors, the temperature sensor and so on. Besides, it can control and drive the motor in PWM and SVPWM modes. What is more, the joint controller has been...
Six-axis force/torque sensor plays an important role in many fields. A novel six-axis force/torque sensor based on strain gauge was designed and optimized with design of experiments (DOE) approach and response surface methodology. In order to reduce the errors bonding strain gauges, we adopted strain distribution analysis to acquire the accurately positions. The strain compliance matrix was attained...
This paper presents experimental results on the five-finger dexterous robot hand DLR-HIT II, with Cartesian impedance control based on joint torque and nonlinearity compensation for elastic dexterous robot joints. To improve the performance of the impedance controller, system parameter estimations with extended kalman filter and gravity compensation have been investigated on the robot hand. Experimental...
This paper presents an overview of the structure and requirements of a ground engineering model for a space remote manipulator system, with long arm and large torque driver capacity. The system consists of a 6 DOFs robot arm composed of six identical modular joints, and a large-error tolerated end effector. A FPGA based joint controller hardware structure is built to form a distributed control scheme...
This paper presents a DSP/FPGA based multi-sensory flexible-joint robot including modular mechanics, hardware and software architecture. The robot is composed of four modular flexible joints and a DLR-HIT-Hand. In each joint there is a Field Programmable Gate Array (FPGA) for sensor data processing, brushless DC motor control and communication. The kernel of the hardware system is a PCI-based high...
In this paper, we discuss a collision detection approach which enables the flexible joint manipulator to work safely in an unstructured environment. By using joint torque sensors, a novel Cartesian impedance control law is proposed to implement the compliance control at first; then adaptive dynamics joint controller is extended to all the joints for achieving precision control performance; furthermore,...
In this paper, a new type of master finger in exoskeleton type has been developed to implement master-slave operation for DLR/HIT dexterous hand. The finger has three novel characteristics. Firstly, the exoskeleton mechanism uses ldquofour-bar mechanism jointrdquo, which rotates about an instant center that coincides with joint center of operator's finger. Secondly, the master finger can distinguish...
In this paper, an improved algorithm to measure Chinapsilas EMU spacesuit joint damping parameters for the old passive robot system is presented. The measuring principle is based on robot kinematics and dynamics. Firstly, a kinematic model of the passive robot and the EMU spacesuitpsilas arm is built according to the special mechanical structure. Secondly, improved methods of solving the inverse kinematics...
A power control strategy for a real variable speed wind turbine system is presented in this paper. The Hinfin-based mixed sensitivity method is applied to realize multi-objective control such as the tracking characteristics for the rated power, poles placement and robustness to disturbances. LMI Toolbox in MATLAB is used to optimize the parameters of Hinfincontroller. First in this paper, a physical...
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