Direct-drive active compliant end effector (active RCC)

1988 ◽  
Vol 4 (3) ◽  
pp. 324-333 ◽  
Author(s):  
H. Kazerooni
Keyword(s):  
Direct Drive ◽  
End Effector

Design and Control of Planar Parallel Mechanisms with High Speed and High Precision

2006 ◽  
Vol 315-316 ◽  
pp. 872-0
Author(s):  
L.N. Sun ◽  
Y.J. Liu ◽  
J. Li ◽  
J. Cui
Keyword(s):  
High Precision ◽  
Disturbance Observer ◽  
High Speed ◽  
Optimization Design ◽  
Advanced Manufacturing ◽  
Parallel Mechanisms ◽  
Direct Drive ◽  
End Effector ◽  
Load Disturbance ◽  
And Control

In order to satisfy the requirement of advanced manufacturing equipments with high speed and high precision, two planar parallel mechanisms have been developed. Based on these mechanisms, firstly, in consideration with the velocity and the precision of the end-effector together, the dimension optimization design is performed based on conditioning index and the precision characteristics. Then a disturbance observer is designed for the purpose of restraining load disturbance in the direct-drive system, and the experimental results show that load disturbance can be effectively restrained by the disturbance observer.

scholarly journals On the Robot Compliant Motion Control

1989 ◽  
Vol 111 (3) ◽  
pp. 416-425 ◽  
Author(s):  
H. Kazerooni
Keyword(s):  
Control Method ◽  
Robot Manipulator ◽  
Direct Drive ◽  
End Effector ◽  
Compliant Motion ◽  
General Stability ◽  
Dc Motors ◽  
Nonlinear Approach ◽  
Fast Light ◽  
Miniature Robot

The work presented here is a nonlinear approach for the control and stability analysis of manipulative systems in compliant maneuvers. Stability of the environment and the manipulator taken as a whole has been investigated using unstructured models for the dynamic behavior of the robot manipulator and the environment, and a bound for stable manipulation has been derived. We show that for stability of the robot, there must be some initial compliancy either in the robot or in the environment. The general stability condition has been extended to the particular case where the environment is very rigid in comparison with the robot stiffness. A fast, light-weight, active end-effector (a miniature robot) which can be attached to the end-point of large commercial robots has been designed and built to verify the control method. The device is a planar, five-bar linkage which is driven by two direct drive, brush-less DC motors. The control method makes the end-effector to behave dynamically as a two-dimensional, Remote Center Compliance (RCC).

A New Kinematic Kalman Filter (KKF) for End-Effector Sensing of Robotic Manipulators

2007 ◽  
Author(s):  
Soo Jeon ◽  
Masayoshi Tomizuka ◽  
Tetsuaki Katou
Keyword(s):  
Kalman Filter ◽  
Real Time ◽  
Sampling Rate ◽  
Accurate Estimation ◽  
Vision Sensor ◽  
Direct Drive ◽  
State Estimator ◽  
Parameter Uncertainties ◽  
End Effector ◽  
The Real

The kinematic Kalman filter (KKF) is a sensor-based state estimator which is immune to the external disturbances and the parameter uncertainties of mechanical plants. This paper extends the original idea of the KKF to a more general form as a means to enhance a real time vision sensor for the end-effector control of a robot manipulator, the performance of which is often limited by its slow sampling rate. The original one-dimensional KKF is reformulated in a higher dimensional form by incorporating the measurements from the vision sensor, accelerometers and gyroscopes. A nonlinear state space model of the kinematics of the end-effector is derived including the time delay associated with vision sensing. Then, the new KKF is formulated as a state estimator combining the inter-sample predictions with an extended Kalman filter (EKF). The paper discusses practical issues such as the real time computation to implement the EKF and the vision sensor to measure the absolute position. Experimental results are presented to confirm the benefits of the new KKF using a two-link direct drive manipulator equipped with a dual axis MEMS accelerometer, a single axis MEMS gyroscope and an end-effector mounted vision camera. The accurate estimation of the position and velocity of the end-effector from the new KKF will be useful for the real time visual-servo and the task space control of robot manipulators.

Inertial and Vision Sensor Based End-Effector Sensing and Control for Robot Manipulators

2010 ◽  
Author(s):  
H. Cheng ◽  
M. Tomizuka
Keyword(s):  
Kalman Filter ◽  
Tracking Control ◽  
Robot Manipulators ◽  
Industrial Robot ◽  
Sampling Rate ◽  
Direct Drive ◽  
End Effector ◽  
Velocity Information ◽  
Accurate Position ◽  
And Control

In the application of industrial robot manipulators, it is often desirable to obtain accurate position and velocity information regarding the end-effector. Estimations based on motor-side encoders alone are often inaccurate due to joint flexibilities and errors in the robot link kinematics. A vision based approach may also be insufficient due to its low sampling rate and image processing and transportation delay. However, with additional accelerometer measurements, a kinematic Kalman filter (KKF) can be formulated to estimate the end-effector motion accurately without encoder signals. The estimation results can be utilized for real time tracking control effectively. In this paper a multirate kinematic Kalman filter (KKF) scheme is formulated using vision and acceleration measurements from the end-effector. Estimations based on the scheme are utilized as feedback signals for tracking control. The effectiveness of the proposed approach is demonstrated by experiments on a single joint direct drive setup.

CAD of a direct drive rotary motor based on giant magnetostrictive alloys

1998 ◽  
Vol 08 (PR2) ◽  
pp. Pr2-785-Pr2-788
Author(s):  
M. E.H. Benbouzid ◽  
G. Reyne ◽  
G. Meunier
Keyword(s):  
Direct Drive ◽  
Rotary Motor
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