Mechanical Design of the Jasper Mobile Manipulator

2008 ◽  
Author(s):  
Darrin Willis ◽  
Scott B. Nokleby ◽  
Remon Pop-Iliev
Keyword(s):  
Robot Manipulator ◽  
Mechanical Design ◽  
Degree Of Freedom ◽  
Mobile Manipulator ◽  
Design Features ◽  
Coupling Device ◽  
Mobile Base

This paper describes the mechanical design and analysis of a mobile-manipulator system comprised of a robot manipulator and a mobile base. The combination of the two is known as a mobile manipulator and combines the maneuverability of the mobile base with the accuracy of the robot manipulator. The mechanical design of a new mobile-manipulator system with the robot manipulator mounted on the front is discussed. The device features an innovative 2-DOF (degree-of-freedom) parallelogram coupling device that allows the base of the robot manipulator to translate vertically and roll longitudinally relative to the mobile base. The coupling device has dampers to reduce the vibrations caused by the motion of the mobile base on the robot manipulator and vice versa. The design features the use of omni-wheels that eliminate the problems inherent with traditional caster wheels.

scholarly journals A New Kinematic Model and Control Strategy for a Mobile Platform for Transporting Lightweight Manipulators

Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 441
Author(s):  
Daniel Feliu-Talegon ◽  
Andres San-Millan ◽  
Vicente Feliu-Batlle
Keyword(s):  
Control Strategy ◽  
Mechanical Design ◽  
Kinematic Model ◽  
Mobile Platform ◽  
Mobile Manipulator ◽  
Mobile Manipulators ◽  
The Real ◽  
And Control ◽  
Mobile Base

This work is concerned with the mechanical design and the description of the different components of a new mobile base for a lightweight mobile manipulator. These kinds of mobile manipulators are normally composed of multiple lightweight links mounted on a mobile platform. This work is focused on the description of the mobile platform, the development of a new kinematic model and the design of a control strategy for the system. The proposed kinematic model and control strategy are validated by means of experimentation using the real prototype. The workspace of the system is also defined.

Cooperation and Null-Space Control of Networked Omni-Directional Mobile Manipulators

2020 ◽  
Author(s):  
Michael John Chua ◽  
Yen-Chen Liu
Keyword(s):  
Degrees Of Freedom ◽  
Null Space ◽  
Kinematic Model ◽  
Mobile Manipulator ◽  
Main Task ◽  
Mobile Manipulators ◽  
Robot Arm ◽  
Task Space ◽  
End Effector ◽  
Mobile Base

Abstract This paper presents cooperation and null-space control for networked mobile manipulators with high degrees of freedom (DOFs). First, kinematic model and Euler-Lagrange dynamic model of the mobile manipulator, which has an articulated robot arm mounted on a mobile base with omni-directional wheels, have been presented. Then, the dynamic decoupling has been considered so that the task-space and the null-space can be controlled separately to accomplish different missions. The motion of the end-effector is controlled in the task-space, and the force control is implemented to make sure the cooperation of the mobile manipulators, as well as the transportation tasks. Also, the null-space control for the manipulator has been combined into the decoupling control. For the mobile base, it is controlled in the null-space to track the velocity of the end-effector, avoid other agents, avoid the obstacles, and move in a defined range based on the length of the manipulator without affecting the main task. Numerical simulations have been addressed to demonstrate the proposed methods.

Discrete-Time LQR and H 2 Damping Control of Flexible Payloads Using a Robot Manipulator With a Wrist-Mounted Force/Torque Sensor

2000 ◽  
Author(s):  
Chunhao Joseph Lee ◽  
Constantinos Mavroidis
Keyword(s):  
Optimal Control ◽  
Discrete Time ◽  
Robot Manipulator ◽  
Control Design ◽  
Degree Of Freedom ◽  
Flexible Beam ◽  
Torque Sensor ◽  
Damping Control ◽  
Control Feedback ◽  
Six Degree Of Freedom

Abstract This paper presents robust and optimal control methods to suppress vibrations of flexible payloads carried by robotic systems. A new improved estimator in discrete-time H2 optimal control design based on the Kalman Filter predictor form is developed here. Two control design methods using state-space models, LQR and H2 Optimal Design, in discrete-time domain are applied and compared. The manipulator joint encoders and the wrist-mounted six-degree-of-freedom force/torque sensor provide the control feedback. A complete dynamic model of the robot/payload system is taken into account to synthesize the controllers. Experimental verifications of both methods are performed using a Mitsubishi five-degree-of-freedom robot manipulator that carries a flexible beam. It is shown that both methods damp out the vibrations of the payload very effectively.

scholarly journals New time delay estimation-based virtual decomposition control for n-DoF robot manipulator

2021 ◽  
Vol 10 (3) ◽  
pp. 192
Author(s):  
Hachmia Faqihi ◽  
Khalid Benjelloun ◽  
Maarouf Saad ◽  
Mohammed Benbrahim ◽  
M. Nabil Kabbaj
Keyword(s):  
Time Delay ◽  
Dynamic Model ◽  
Control Strategy ◽  
Robot Manipulator ◽  
Time Delay Estimation ◽  
Lyapunov Theory ◽  
Degree Of Freedom ◽  
Delay Estimation ◽  
The Stability

<p>One of the most efficient approaches to control a multiple degree-of-freedom robot manipulator is the virtual decomposition control (VDC). However, the use of the re- gressor technique in the conventionnal VDC to estimate the unknown and uncertaities parameters present some limitations. In this paper, a new control strategy of n-DoF robot manipulator, refering to reorganizing the equation of the VDC using the time delay estimation (TDE) have been investigated. In the proposed controller, the VDC equations are rearranged using the TDE for unknown dynamic estimations. Hence, the decoupling dynamic model for the manipulator is established. The stability of the overall system is proved based on Lyapunov theory. The effectiveness of the proposed controller is proved via case study performed on 7-DoF robot manipulator and com- pared to the conventionnal Regressor-based VDC according to some evalution criteria. The results carry out the validity and efficiency of the proposed time delay estimation- based virtual decomposition controller (TD-VDC) approach.</p>

The Effect of Water Injection for Emissions Control on Industrial Gas Turbine Combustors

1984 ◽  
Author(s):  
R. J. Antos ◽  
W. C. Emmerling
Keyword(s):  
Gas Turbines ◽  
Mechanical Design ◽  
Water Injection ◽  
Combustion Process ◽  
Liquid Fuels ◽  
Nox Emissions ◽  
Design Features ◽  
Industrial Gas Turbines ◽  
Comprehensive Test ◽  
Industrial Gas Turbine

One common method of reducing the NOx emissions from industrial gas turbines is to inject water into the combustion process. The amount of water injected depends on the emissions rules that apply to a particular unit. Westinghouse W501B industrial gas turbines have been operated at water injection levels required to meet EPA NOx emissions regulations. They also have been operated at higher injection levels required to meet stricter California regulations. Operation at the lower rates of water did not affect combustor inspection and/or repair intervals. Operation on liquid fuels with high rates of water also did not result in premature distress. However, operation on gas fuel at high rates of water did cause premature distress in the combustors. To evaluate this phenomenon, a comprehensive test program was conducted; it demonstrated that the distress is the result of the temperature patterns in the combustor caused by the high rates of water. The test also indicated that there is no significant change in dynamic response levels in the combustor. This paper presents the test results, and the design features selected to substantially improve combustor wall temperature when operating on gas fuels, with the high rates of water injection required to meet California applications. Mechanical design features that improve combustor resistance to water injection-induced thermal gradients also are presented.

Reversible Pump-Turbines for Sir Adam Beck-Niagara Pumping-Generating Station

1959 ◽  
Vol 81 (4) ◽  
pp. 521-529 ◽  
Author(s):  
P. Deriaz ◽  
J. G. Warnock
Keyword(s):  
Mechanical Design ◽  
Hydraulic Characteristics ◽  
Design Features ◽  
Pump Turbine ◽  
Storage Scheme ◽  
New Machine

The paper describes the origin of the new machine and its application to the storage scheme at Sir Adam Beck-Niagara where it operates as a reversible pump-turbine. Description is given of its hydraulic characteristics and of some of the more important mechanical design features.

A new method for calculating the Jacobian for a robot manipulator

Robotica ◽  
1983 ◽  
Vol 1 (4) ◽  
pp. 205-209 ◽  
Author(s):  
Jadran Lenarčič
Keyword(s):  
Computational Efficiency ◽  
Execution Time ◽  
Robot Manipulator ◽  
Degree Of Freedom ◽  
New Method ◽  
Trigonometric Functions

SUMMARYA new method for calculating the Jacobian for a general n degree-of-freedom robot manipulator is presented and compared with some known other methods. The computational efficiency of the method is estimated in terms of the number of multiplications, additions/subtractions, trigonometric functions required, and the execution time on a VAX 11/750 computer. It is shown that the new method proposed in this paper is one of the most efficient when applied on a robot manipulator with successively parallel or rectangular joint rotations.

Design of a High-Speed Spherical Four-Bar Mechanism for Use in a Motion Common in Assembly Processes

2007 ◽  
Author(s):  
Andrew P. Murray ◽  
Franc¸ois Pierrot
Keyword(s):  
Sensitivity Analysis ◽  
High Speed ◽  
Mechanical Design ◽  
Degree Of Freedom ◽  
Kinematic Synthesis ◽  
Control Scheme ◽  
Smooth Motion ◽  
Spherical Mechanism

In this paper, we present the mechanical design of a spherical four-bar mechanism for performing a motion common in manufacturing and assembly processes. The mechanism is designed to create, in a single, smooth motion, the combined rotation of a body by 90 degrees about one axis with a 90 degree rotation about an axis perpendicular to the first. A spherical four-bar mechanism is pursued as the basis for the design because the reorientation is produced mechanically rather than via a control scheme typical when higher degree of freedom systems are utilized. The design initiates with the kinematic synthesis of the spherical mechanism to guide a body through two orientations. The next step in the design is to refine the spherical fourbar based on manufacturing and operational concerns. As one of the challenges of utilizing these four-bars is tuning the starting and ending angle for the mechanism’s motion, a sensitivity analysis is performed to gauge the needed accuracy. Finally, there are details and a discussion of the proposed mechanical design.

Towards Remote Teleoperation of a Semi-Autonomous Mobile Manipulator System in Machine Tending Tasks

2019 ◽  
Author(s):  
Vivek Annem ◽  
Pradeep Rajendran ◽  
Shantanu Thakar ◽  
Satyandra K. Gupta
Keyword(s):  
Material Handling ◽  
Point Clouds ◽  
Mobile Manipulator ◽  
Depth Cameras ◽  
Level Of Automation ◽  
Volume Production ◽  
Manufacturing Applications ◽  
High Level ◽  
The Given ◽  
Mobile Base

Abstract Increasing the level of automation in material handling tasks in small volume production operations can improve human productivity and overall manufacturing system performance. In this paper, we present a teleoperated mobile manipulator system that can be used for tending machines and transporting parts in manufacturing applications. The remotely located human operator can interact with the semi-autonomous mobile manipulator by giving it high level instructions. We have incorporated several sensors on the system to ensure safe teleoperation where the operator gives only high level motion goals to the mobile manipulator, such as waypoints for mobile base motion, and interactive marker poses for the manipulator motion. The point clouds from multiple depth cameras are used for mapping the environment. The robot plans for autonomous motions between the given way-points ensuring that the resulting motions are collision-free. We have conducted case studies with two different types of parts to be extracted from a 3D printer. The system is tested by multiple users. They were successful in completing tasks in a reasonable amount of time using our interface.

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