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.

Kinematic Kalman Filter (KKF) for Robot End-Effector Sensing

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Soo Jeon ◽  
Masayoshi Tomizuka ◽  
Tetsuaki Katou
Keyword(s):  
Kalman Filter ◽  
High Speed ◽  
High Performance ◽  
Control Strategies ◽  
Sampling Rate ◽  
Body Motion ◽  
Vision Sensor ◽  
End Effector ◽  
Measurement Delay ◽  
Velocity Information

In control of industrial manipulators, the position from the motor encoder has been the only sensor measurement for axis control. In this case, it is not easy to estimate the end-effector motion accurately because of the kinematic errors of links, joint flexibility of gear mechanisms, and so on. Direct measurement of the end-effector using the vision sensor is considered as a solution but its performance is often limited by the slow sampling rate and the latency. To overcome these limitations, this paper extends the basic idea of the kinematic Kalman filter (KKF) to general rigid body motion leading to the formulation of the multidimensional kinematic kalman filter (MD-KKF). By combining the measurements from the vision sensor, the accelerometers and the gyroscopes, the MD-KKF can recover the intersample values and compensate for the measurement delay of the vision sensor providing the state information of the end-effector fast and accurately. The performance of the MD-KKF is verified experimentally using a planar two-link robot. The MD-KKF will be useful for widespread applications such as the high speed visual servo and the high-performance trajectory learning for robot manipulators, as well as the control strategies which require accurate velocity information.

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.

Micro/Macro or Link-Integrated Micro-actuator Manipulation—A Kinematics and Dynamics Perspective

2006 ◽  
Vol 129 (10) ◽  
pp. 1086-1093 ◽  
Author(s):  
J. Zhang ◽  
J. Rastegar
Keyword(s):  
Dynamic Response ◽  
Closed Loop ◽  
Robot Manipulator ◽  
Robot Manipulators ◽  
High Harmonic ◽  
Kinematics And Dynamics ◽  
Control Problems ◽  
End Effector ◽  
Micro Actuators ◽  
And Control

Smart (active) materials based actuators, hereinafter called micro-actuators, have been shown to be well suited for the elimination of high harmonics in joint and/or end-effector motions of robot manipulators and in the reduction of actuator dynamic response requirements. Low harmonic joint and end-effector motions, as well as low actuator dynamic response requirements, are essential for a robot manipulator to achieve high operating speed and precision with minimal vibration and control problems. Micro-actuators may be positioned at the end-effector to obtain a micro- and macro-robot manipulation configuration. Alternatively, micro-actuators may be integrated into the structure of the links to vary their kinematics parameters, such as their lengths during the motion. In this paper, the kinematics and dynamics consequences of each of the aforementioned alternative are studied for manipulators with serial and closed-loop chains. It is shown that for robot manipulators constructed with closed-loop chains, the high harmonic components of all joint motions can be eliminated only when micro-actuators are integrated into the structure of the closed-loop chain links. The latter configuration is also shown to have dynamics advantage over micro- and macro-manipulator configuration by reducing the potential vibration and control problems at high operating speeds. The conclusions reached in this study also apply to closed-loop chains of parallel and cooperating robot manipulators.

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.

Tracking Control of Robot Manipulators Using a Robust Deterministic Control Law

1998 ◽  
Vol 120 (4) ◽  
pp. 537-541 ◽  
Author(s):  
C.-G. Kang ◽  
R. Horowitz ◽  
G. Leitmann
Keyword(s):  
Dynamic Systems ◽  
Tracking Control ◽  
Robot Manipulators ◽  
Experimental Studies ◽  
Control Law ◽  
Direct Drive ◽  
Control Scheme ◽  
Deterministic Control ◽  
Two Degree Of Freedom ◽  
Theoretical Developments

There have been theoretical developments on the control of dynamic systems based on deterministically uncertain and singularly perturbed models in recent years. In this paper, a robust deterministic control scheme proposed originally by M. Corless et al. is modified, and is applied to the tracking control of robot manipulators. Simulation and experimental studies for a two degree of freedom, direct drive SCARA manipulator are conducted to evaluate the effectiveness of the control scheme.

scholarly journals Tracking Control of Autonomous Underwater Vehicles with Acoustic Localization and Extended Kalman Filter

2021 ◽  
Vol 11 (17) ◽  
pp. 8038
Author(s):  
Dongzhou Zhan ◽  
Huarong Zheng ◽  
Wen Xu
Keyword(s):  
Kalman Filter ◽  
Extended Kalman Filter ◽  
Tracking Control ◽  
Autonomous Underwater Vehicles ◽  
Acoustic Signals ◽  
Underwater Vehicles ◽  
Ocean Currents ◽  
Acoustic Localization ◽  
And Control ◽  
Constraints Model

The absence of global positioning system (GPS) signals and the influence of ocean currents are two of the main challenges facing the autonomy of autonomous underwater vehicles (AUVs). This paper proposes an acoustic localization-based tracking control method for AUVs. Particularly, three buoys that emit acoustic signals periodically are deployed over the surface. Times of arrivals of these acoustic signals at the AUV are then obtained and used to calculate an estimated position of the AUV. Moreover, the uncertainties involved in the localization and ocean currents are handled together in the framework of the extended Kalman filter. To deal with system physical constraints, model predictive control relying on online repetitive optimizations is applied in the tracking controller design. Furthermore, due to the different sampling times between localization and control, the dead-reckoning technique is utilized considering detailed AUV dynamics. To avoid using the highly nonlinear and complicated AUV dynamics in the online optimizations, successive linearizations are employed to achieve a trade-off between computational complexity and control performance. Simulation results show that the proposed algorithms are effective and can achieve the AUV tracking control goals.

scholarly journals Differential Kinematics Of Contemporary Industrial Robots

2014 ◽  
Vol 19 (3) ◽  
pp. 643-659
Author(s):  
T. Szkodny
Keyword(s):  
Closed Form ◽  
Robot Manipulators ◽  
Industrial Robot ◽  
Industrial Robots ◽  
The Other ◽  
Simple Method ◽  
End Effector ◽  
Singular Configurations ◽  
Global Form

Abstract The paper presents a simple method of avoiding singular configurations of contemporary industrial robot manipulators of such renowned companies as ABB, Fanuc, Mitsubishi, Adept, Kawasaki, COMAU and KUKA. To determine the singular configurations of these manipulators a global form of description of the end-effector kinematics was prepared, relative to the other links. On the basis of this description , the formula for the Jacobian was defined in the end-effector coordinates. Next, a closed form of the determinant of the Jacobian was derived. From the formula, singular configurations, where the determinant’s value equals zero, were determined. Additionally, geometric interpretations of these configurations were given and they were illustrated. For the exemplary manipulator, small corrections of joint variables preventing the reduction of the Jacobian order were suggested. An analysis of positional errors, caused by these corrections, was presented

Micro-Macro or Link-Integrated Micro-Actuator Manipulation: A Kinematics and Dynamics Perspective

2005 ◽  
Author(s):  
J. Zhang ◽  
J. Rastegar
Keyword(s):  
Dynamic Response ◽  
Closed Loop ◽  
Robot Manipulator ◽  
Robot Manipulators ◽  
Active Material ◽  
Kinematics And Dynamics ◽  
Control Problems ◽  
End Effector ◽  
Micro Actuators ◽  
And Control

Smart (active) material based actuators, hereinafter called micro-actuators, have been shown to be well suited for the elimination of high harmonics in joint and/or end-effector motions of the robot manipulators and reduce actuator dynamic response requirements. Low harmonic joint and end-effector motions as well as low actuator dynamic response requirements are essential for a robot manipulator to be capable of operating at high speeds with greater precision and with less vibration and control problems. Micro-actuators may be positioned at the end-effector to obtain a micro and macro robot manipulation. Alternatively, micro-actuators may be integrated into the links to vary a link parameter such as the link length. In this paper, the kinematics and dynamics consequences of each alternative are studies for manipulators with serial and closed-loop chains. It is shown that for the robot manipulator constructed with closed-loop chains, the high harmonic components of all joint motions can be eliminated only when micro-actuators are integrated into the structure of the closed-loop chain links. The latter configuration is also shown to have dynamics advantage over micro and macro configuration. thereby reducing the potential vibration and control problems at higher operating speeds. The conclusions also apply to closed-loop chains of parallel and cooperating robot manipulators.

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