Manipulator control using the configuration space method

1978 ◽  
Vol 5 (2) ◽  
pp. 69-73 ◽  
Author(s):  
M.H. Raibert
Keyword(s):  
Real Time ◽  
Configuration Space ◽  
Degrees Of Freedom ◽  
Control Method ◽  
Equations Of Motion ◽  
Tabular Form ◽  
Gravity Acceleration ◽  
Manipulator Control ◽  
Space Method ◽  
Manipulation Process

The throughput of a manipulation process depends upon the arm's speed of operation, but many existing controllers provide accurate trajectory control only at low or moderate velocities. We propose a control method that explicitly compensates for configuration‐dependent gravity, acceleration, and velocity forces ‐ the latter being especially important during rapid simultaneous motions of a number of joints. A tabular form of the equations of motion is used in real‐time in conjunction with a configuration space memory organized by positional variables. The contents of the memory are pre‐computed only once for each manipulator and are usable for all possible movements. A planned implementation of this method for the Stanford Schienman arm that uses about 250K memory locations and requires about n3 + 3n2 arithmetic operations per evaluation is discussed, where n is the number of degrees of freedom of the device.

Joint Self-Tuning With Cartesian Setpoints

1986 ◽  
Vol 108 (2) ◽  
pp. 146-150 ◽  
Author(s):  
P. G. Backes ◽  
G. G. Leininger ◽  
Chun-Hsien Chung
Keyword(s):  
Real Time ◽  
Control Method ◽  
Hybrid Control ◽  
Pole Placement ◽  
Real Time Control ◽  
Time Control ◽  
Self Tuning ◽  
Cause Of Error ◽  
Time Position ◽  
Manipulator Control

A joint coordinate self-tuning manipulator control method is presented which uses Cartesian setpoints. The method is capable of both position and hybrid control. Position and force errors are transformed from Cartesian coordinates to position and force errors at the joints. The position and force errors at each joint are combined into one hybrid error that is eliminated using pole-placement self-tuning. Real time position and hybrid control results are given. No prior knowledge of manipulator or load dynamics is required and real time control results show that the goal of consistent control with changing load dynamics is achieved. The major cause of error in position and hybrid control is the large friction effects in the joints.

scholarly journals Study on Control Method for Redundant Manipulator. Control of Tomato Harvesting Manipulator with 7 Degrees of Freedom.

1993 ◽  
Vol 5 (1) ◽  
pp. 44-53
Author(s):  
Naoshi KONDO ◽  
Mitsuji MONTA ◽  
Tateshi FUJIURA ◽  
Yasunori SHIBANO ◽  
Kentaro MOHRI ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Control Method ◽  
Redundant Manipulator ◽  
Manipulator Control

Real-Time Motion Capture for a Human Body using Accelerometers

Robotica ◽  
2001 ◽  
Vol 19 (6) ◽  
pp. 601-610 ◽  
Author(s):  
Jihong Lee ◽  
Insoo Ha
Keyword(s):  
Real Time ◽  
Motion Capture ◽  
Human Body ◽  
Degrees Of Freedom ◽  
Low Cost ◽  
Human Motion ◽  
The Body ◽  
Sensor Data ◽  
Time Motion ◽  
Gravity Acceleration

In this paper we propose a set of techniques for a real-time motion capture of a human body. The proposed motion capture system is based on low cost accelerometers, and is capable of identifying the body configuration by extracting gravity-related terms from the sensor data. One sensor unit is composed of 3 accelerometers arranged orthogonally to each other, and is capable of identifying 2 rotating angles of joints with 2 degrees of freedom. A geometric fusion technique is applied to cope with the uncertainty of sensor data. A practical calibration technique is also proposed to handle errors in aligning the sensing axis to the coordination axis. In the case where motion acceleration is not negligible compared with gravity acceleration, a compensation technique to extract gravity acceleration from the sensor data is proposed. Experimental results not only for individual techniques but also for human motion capturing with graphics are included.

A REAL-TIME EMG-DRIVEN ARM WRESTLING ROBOT CONSIDERING MOTION CHARACTERISTICS OF HUMAN UPPER LIMBS

2007 ◽  
Vol 04 (04) ◽  
pp. 645-670 ◽  
Author(s):  
QUANJUN SONG ◽  
YONG YU ◽  
YUNJIAN GE ◽  
ZHEN GAO ◽  
HUANGHUAN SHEN ◽  
...  
Keyword(s):  
Neural Network ◽  
Real Time ◽  
Degrees Of Freedom ◽  
Control Method ◽  
Wavelet Packet ◽  
Neuromuscular Control ◽  
Joint Force ◽  
Mems Accelerometers ◽  
Usb Camera ◽  
Motion Characteristics

An EMG-driven Arm Wrestling Robot (AWR) is developed for the purposes of studying neuromuscular control of human elbow movements. The AWR arm has two degrees-of-freedom, integrated with mechanical arm, elbow/wrist force sensors, servo motors, encoders, MEMS accelerometers, and a USB camera, and is used to estimate tension generated by individual muscles from recorded electromyograms (EMG). The surface electromyography signal from the upper limb is sampled from a real player in the same conditions. By using the method of wavelet packet transformation (WPT) and autoregressive model (AR), the characteristics of EMG signals can be extracted. Then, an artificial neural network is adopted to estimate the elbow joint force. The effectiveness of the control method using force control estimated via neural network using WPT and AR as inputs is confirmed by experiments. The purpose of this paper is to describe the design objectives, fundamental components, and implementation of our real-time, EMG-driven AWR arm.

Servo-Constraint Based Computed Torque Control of Underactuated Mechanical Systems

2011 ◽  
Author(s):  
La´szlo´ L. Kova´cs ◽  
Jo´zsef Ko¨vecses ◽  
Ambrus Zelei ◽  
La´szlo´ Bencsik ◽  
Ga´bor Ste´pan
Keyword(s):  
Degrees Of Freedom ◽  
Control Method ◽  
Equations Of Motion ◽  
Geometric Constraints ◽  
Torque Control ◽  
Underactuated Mechanical Systems ◽  
Computed Torque Control ◽  
Distribution Matrix ◽  
Underactuated Robot ◽  
Computed Torque

This paper aims to generalize the computed torque control method for underactuated systems which are modeled by a non-minimum set of generalized coordinates subjected to geometric constraints. The control task of the underactuated robot is defined in the form of servo constraint equations that have the same number as the number of independent control inputs. A PD controller is synthesized based on projecting the equations of motion into the nullspace of the distribution matrix of the actuator forces/torques. The results are demonstrated by numerical simulation and experiments conducted on a two degrees-of-freedom device.

A Master–Slave Control Method for Dexterous Hands with Shaking Elimination Strategy

2017 ◽  
Vol 14 (01) ◽  
pp. 1650016
Author(s):  
Wenzhen Yang ◽  
Xinli Wu ◽  
Shiguang Yu
Keyword(s):  
Real Time ◽  
Degrees Of Freedom ◽  
Control Method ◽  
Integrated Control ◽  
Open Loop ◽  
Loop Control ◽  
Data Glove ◽  
Motion Data ◽  
Hand Joints ◽  
Dexterous Hand

With the limitations of the artificial intelligence, automatic control and sensor technologies, the dexterous hand in unstructured environments to achieve fully autonomous operations is still very difficult. This paper proposed a master–slave control method for dexterous hands with the combination of the data glove and the micro-stepper motor. The hardware of this method included CyberGloveII device, personal computer (PC), integrated control board (ICB), and YWZ dexterous hand (a multi-fingered robot hand with 20 active degrees of freedom (DOFs)). By the CyberGloveII device, we gained human finger joints motion data in real-time firstly, which were preprocessed by a shaking elimination algorithm to ensure the motion stability of the dexterous hand. Then, the motion data were mapped to the dexterous hand joints, respectively. A communication protocol was designed to transfer the motion data between the PC and the ICB. The motion data were transmitted into the ICB through a serial interface driving the corresponding dexterous hand joints. The experimental results showed that this method is feasible, can achieve the open-loop control of dexterous hands, and has excellent movement accuracy, real-time and stability.

A real-time motion planning algorithm for a hyper-redundant set of mechanisms

Robotica ◽  
2013 ◽  
Vol 31 (8) ◽  
pp. 1327-1335 ◽  
Author(s):  
Nir Shvalb ◽  
Boaz Ben Moshe ◽  
Oded Medina
Keyword(s):  
Motion Planning ◽  
Real Time ◽  
Configuration Space ◽  
Degrees Of Freedom ◽  
Morse Function ◽  
Climbing Robot ◽  
Probabilistic Algorithm ◽  
Road Map ◽  
Time Motion ◽  
Planning Algorithm

SUMMARYWe introduce a novel probabilistic algorithm (CPRM) for real-time motion planning in the configuration space${\EuScript C}$. Our algorithm differs from a probabilistic road map (PRM) algorithm in the motion between a pair of anchoring points (local planner) which takes place on the boundary of the obstacle subspace${\EuScript O}$. We define a varying potential fieldfon ∂${\EuScript O}$as a Morse function and follow$\vec{\nabla} f$. We then exemplify our algorithm on a redundant worm climbing robot withndegrees of freedom and compare our algorithm running results with those of the PRM.

scholarly journals Dynamic Models of Unmanned Aerial Vehicle Manipulator Control and Stabilization

2021 ◽  
Vol 24 (4) ◽  
pp. 200-216
Author(s):  
V. V. Nguyen ◽  
E. E. Usina
Keyword(s):  
Control System ◽  
Unmanned Aerial Vehicle ◽  
Degrees Of Freedom ◽  
Dynamic Models ◽  
Control Method ◽  
Kinematic Model ◽  
Acceptable Result ◽  
Manipulation System ◽  
Aerial Vehicle ◽  
Manipulator Control

Purpose or research. Improving guidance accuracy of robotic capture mounted on an unmanned aerial vehicle and the stability of combined aerial manipulation system is the main objective of this study. In order to achieve this goal, a particular task of developing a manipulator control system that considers joint working space of manipulator and unmanned aerial vehicle has been solved. Methods. Kinematic model of a manipulator with three degrees of freedom is proposed in this work. This is a part of air manipulation system of quadrotor. Rotary movement of two successive links is performed by means of hinge joint. Direct and inverse kinematic tasks were solved for this manipulator. Equations for dynamic model were also obtained. Dynamic response of each link is sufficient for quick stabilization of the system with little re-adjustment. Self-tuning fuzzy proportional-integral-differentiating (PID) regulator was developed based on these data to control the manipulator. Control system for each manipulator link consists of a PID regulator and a fuzzy PID output using Mamdani method. Results. Simulation of developed manipulator control system was carried out in the absence of disturbances. The proposed control system satisfies specified requirements and ensures continuous and smooth movement of manipulator links in calculated trajectory. Conclusion. The developed three-link manipulator motion control method provides a horizontal mass center shift not more than 1.25 mm, which is an acceptable result for rapid stabilization of unmanned aerial manipulator and further practical experiments.

An Approach to Vibration Control of Multiple-Pendulum System by Wave Absorption

1998 ◽  
Vol 120 (2) ◽  
pp. 524-533 ◽  
Author(s):  
M. Saigo ◽  
N. Tanaka ◽  
K. Tani
Keyword(s):  
Degrees Of Freedom ◽  
Deflection Angle ◽  
Control Method ◽  
Equations Of Motion ◽  
Simulation Method ◽  
Traveling Wave Solution ◽  
New Wave ◽  
Pendulum System ◽  
Time Simulation ◽  
The Difference

In this paper, a new wave-absorbing strategy has been studied to suppress the vibration of a multiple-pendulum system by controlling the lateral movement of the support. The wave-absorbing condition is derived from the difference between the equation of motion of the boundary pendulum and that of an inner pendulum. An online real-time simulation method using the numerical solution is proposed to control the movement that satisfies the wave-absorbing condition. According to this method, vibration of a multiple-pendulum system with arbitrary degrees of freedom can be controlled by measuring only the deflection angle of the uppermost pendulum adjacent to the support if the dimensions of the uppermost pendulum and the total mass of the system are known. Both the numerical simulations and the experiments have confirmed the effectiveness of this method. The basic idea of this control method can easily be applied to any discrete vibrating system whose equations of motion have no traveling-wave solution.

The motion of a lunar orbiter

1966 ◽  
Vol 25 ◽  
pp. 373
Author(s):  
Y. Kozai
Keyword(s):  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Artificial Satellite ◽  
Equations Of Motion ◽  
Triaxial Ellipsoid ◽  
The Moon ◽  
Secular Motion ◽  
The Earth ◽  
Close Satellite ◽  
The Mean

The motion of an artificial satellite around the Moon is much more complicated than that around the Earth, since the shape of the Moon is a triaxial ellipsoid and the effect of the Earth on the motion is very important even for a very close satellite.The differential equations of motion of the satellite are written in canonical form of three degrees of freedom with time depending Hamiltonian. By eliminating short-periodic terms depending on the mean longitude of the satellite and by assuming that the Earth is moving on the lunar equator, however, the equations are reduced to those of two degrees of freedom with an energy integral.Since the mean motion of the Earth around the Moon is more rapid than the secular motion of the argument of pericentre of the satellite by a factor of one order, the terms depending on the longitude of the Earth can be eliminated, and the degree of freedom is reduced to one.Then the motion can be discussed by drawing equi-energy curves in two-dimensional space. According to these figures satellites with high inclination have large possibilities of falling down to the lunar surface even if the initial eccentricities are very small.The principal properties of the motion are not changed even if plausible values ofJ3andJ4of the Moon are included.This paper has been published in Publ. astr. Soc.Japan15, 301, 1963.

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