scholarly journals Efficiency of different control strategies in a force-feedback gripper

Author(s):  
O. B. Lőrinczi ◽  
T. Szalay ◽  
P. Aradi
Author(s):  
Stefano Cenci ◽  
Giulio Rosati ◽  
Damiano Zanotto ◽  
Fabio Oscari ◽  
Aldo Rossi

According to a recent report of ILO (International Labour Organization), more than two million people die or loose the working capability every year because of accidents or work-related diseases. A large portion of these accidents are related to the execution of motion and transportation tasks involving heavy duty machines. The insufficient degree of interaction between the human operator and the machine may be regarded as one of the major causes of this phenomenon. The main goal of the tele-operation system presented in this paper is to both preserving slave (machine) stability, by reducing the inputs of slave actuators when certain unsafe working conditions occur, and improving the level of interaction at master (operator) side. Different control schemes are proposed in the paper, including several combinations of master and slave control strategies. The effectiveness of the algorithms is analyzed by presenting some experimental results, based on the use of a two degrees-of-freedom force feedback input device (with one active actuator and one passive stiff joint) coupled with a simulator of a telescopic handler.


Author(s):  
Daniel Banks ◽  
Jos van ’t Hoff ◽  
Kenneth Doherty

An Oscillating Wave Surge Converter (OWSC) is a Wave Energy Converter (WEC) that consists of a bottom-hinged flap which oscillates due to wave action. Extensive research has been performed on this type of WEC through small scale experimental wave tank tests. One of the key challenges of experimental testing is replicating the characteristics of the Power Take-Off (PTO) system of the equivalent full scale WEC. Many scale models rely on simplified mechanical designs to simulate a PTO system. This can often restrict the experimental research into the influence of PTO design and control strategies of WECs. In order to model PTO systems and control strategies more accurately other tools are needed. This paper describes the design and build of a PLC controlled Force Feedback Dynamometer (FFD) system that enables the testing of more sophisticated control strategies applicable to an OWSC through fast application of a variable PTO damping torque. A PLC system is shown to be a viable control for PTO strategy investigations through velocity triggered damping levels. Examples of both PTO and position control strategies are presented.


2001 ◽  
Vol 10 (5) ◽  
pp. 465-476 ◽  
Author(s):  
Simon P. DiMaio ◽  
Septimiu E. Salcudean ◽  
Claude Reboulet

An excavator simulator has been developed to facilitate the training of human operators and to evaluate control strategies for heavy-duty hydraulic machines. The operator controls a virtual excavator by means of a joystick while experiencing visual and force feedback generated by environment and machine models. The simulator comprises an impedance model of the excavator arm, a model for the bucket-ground interaction forces, a graphically rendered visual environment, and a haptic interface. This paper describes the simulator components and their integration.


2019 ◽  
Vol 40 (1) ◽  
pp. 95-104 ◽  
Author(s):  
Xinbo Yu ◽  
Shuang Zhang ◽  
Liang Sun ◽  
Yu Wang ◽  
Chengqian Xue ◽  
...  

Purpose This paper aims to propose cooperative control strategies for dual-arm robots in different human–robot collaborative tasks in assembly processes. The authors set three different regions where robot performs different collaborative ways: “teleoperate” region, “co-carry” region and “assembly” region. Human holds the “master” arm of dual-arm robot to operate the other “follower” arm by our proposed controller in “teleoperation” region. Limited by the human arm length, “follower” arm is teleoperated by human to carry the distant object. In the “co-carry” region, “master” arm and “follower” arm cooperatively carry the object to the region close to the human. In “assembly” region, “follower” arm is used for fixing the object and “master” arm coupled with human is used for assembly. Design/methodology/approach A human moving target estimated method is proposed for decreasing efforts for human to move “master” arm, radial basis functions neural networks are used to compensate for uncertainties in dynamics of both arms. Force feedback is designed in “master” arm controller for human to perceive the movement of “follower” arm. Experimental results on Baxter robot platform show the effectiveness of this proposed method. Findings Experimental results on Baxter robot platform show the effectiveness of our proposed methods. Different human-robot collaborative tasks in assembly processes are performed successfully under our cooperative control strategies for dual-arm robots. Originality/value In this paper, cooperative control strategies for dual-arm robots have been proposed in different human–robot collaborative tasks in assembly processes. Three different regions where robot performs different collaborative ways are set: “teleoperation” region, “co-carry” region and “assembly” region.


2010 ◽  
Vol 2010 ◽  
pp. 1-16 ◽  
Author(s):  
Satoshi Suzuki ◽  
Fumio Harashima ◽  
Katsuhisa Furuta

Human characteristics concerning voluntary motion control are investigated, because this motion is fundamental for the machine operation and human-computer system. Using a force feedback haptic device and a balancing task of a virtual inverted pendulum, participants were trained in the task, and hand motion/force was measured, and brain activity was monitored. First, through brain analysis by near-infrared spectroscopy (NIRS) and motion analysis of the pendulum, we identified a participant who was the most expert. Next, control characteristics of the most expert were investigated by considering the operational force and delay factor of a human. As a result, it was found that predictive control based on velocity information was used predominantly although a perception feedback control against the pendulum posture worked. And it was shown that an on-off intermittency control, which was a strategy for the skilled balancing, can be described well by a liner model involving two types of time shifts for the position and velocity. In addition, it was confirmed that the cortex activity for observation in an ocular motor control area and visual processing area was strong to enhance above-mentioned control strategies.


2018 ◽  
Vol 12 (1) ◽  
pp. 5-10
Author(s):  
Paweł Bachman ◽  
Andrzej Milecki

AbstractThe term haptic is used to indicate the presence of force feedback from the manipulated object to the operator. One of the most commonly used haptic devices are joysticks. Such joysticks can be successfully applied also in communication with drive system, giving the human operator a feel of the output force. In the paper one axis joystick with force feedback used to control the electrohydraulic drive is proposed. In this joystick, a controlled brake with magnetorheological fluid and a small DC motor are applied. A beam with a strain gauge is used in a joystick arm, enabling the measurement of the force. In the joystick axis also a potentiometer is assembled, which measured the current arm position. In order to develop the control algorithms an electrohydraulic drive simulation and virtual model is worked out and then a haptic joystick is connected to it. The simulation results that have been obtained, enabled to design and test impedance and admittance control strategies for the system composed of haptic joystick and a real electrohydraulic drive. Finally the whole system is built, implemented and investigated in a laboratory environment. Investigations are conducted in conditions similar to real ones, in a situation where hydraulic piston touches an obstacle and the operator cannot observe this piston very accurately. Fifteen operators have been tested this way. The outcomes indicate that haptic control can improve the human feeling of forces between electrohydraulic drive and an obstacle and, thanks to this, the manual control is more accurate and safer.


2017 ◽  
Author(s):  
Kelly N. Clark ◽  
Nicole B. Dorio ◽  
Michelle K. Demaray ◽  
Christine K. Malecki

2014 ◽  
Author(s):  
Christine Ringler ◽  
Andrea Morales ◽  
Steven Nowlis

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