Validation of a Novel In-Vitro Simulator for Real-Time Control of Active Shoulder Movements in Various Planes of Motion

2013 ◽  
Author(s):  
J. W. Giles ◽  
L. M. Ferreira ◽  
G. S. Athwal ◽  
J. A. Johnson
Keyword(s):  
Real Time ◽  
Degrees Of Freedom ◽  
A Priori ◽  
Axial Rotation ◽  
Open Loop ◽  
Abduction Angle ◽  
Real Time Control ◽  
Loop Control ◽  
Shoulder Motion

In-vitro simulation of active shoulder joint motion is critical to gaining an understanding of the effects of surgical procedures and implant designs. However, development of systems for the accurate simulation of active shoulder motion has lagged well behind those implemented for the lower limb and elbow, which have used principles of closed-loop joint angle control 1,4. In contrast, active shoulder motion has been confined to simulators that can hold static joint angles through the application of loads based on computer model outputs 2, or that use constant velocity of the middle deltoid while using open-loop control to apportion other muscle loads as a function of a-priori physiologic loading ratios 3. Neither of these schemes utilizes real-time feedback of kinematic data in order to follow smooth, predefined profiles. The lack of more refined shoulder simulators, based on control theory, can primarily be attributed to the complexity of shoulder motion and the number of degrees of freedom (DOFs) ( i.e. plane of abduction, abduction angle, and axial rotation) which must be controlled.

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.

Real Time, Near-Optimal Trajectory Planning of an Omni-Directional Vehicle

2001 ◽  
Author(s):  
Tamás Kalmár-Nagy ◽  
Pritam Ganguly ◽  
Raffaello D’Andrea
Keyword(s):  
Real Time ◽  
Optimal Trajectory ◽  
Degrees Of Freedom ◽  
Dynamic Environments ◽  
Real Time Control ◽  
Uncertain Environments ◽  
Time Control ◽  
Innovative Method ◽  
Optimal Trajectory Planning ◽  
Three Degrees Of Freedom

Abstract In this paper, we discuss an innovative method of generating near-optimal trajectories for a robot with omni-directional drive capabilities, taking into account the dynamics of the actuators and the system. The relaxation of optimality results in immense computational savings, critical in dynamic environments. In particular, a decoupling strategy for each of the three degrees of freedom of the vehicle is presented, along with a method for coordinating the degrees of freedom. A nearly optimal trajectory for the vehicle can typically be calculated in less than 1000 floating point operations, which makes it attractive for real-time control in dynamic and uncertain environments.

scholarly journals Human-Robot Interaction with Robust Prediction of Movement Intention Surpasses Manual Control

2020 ◽  
Author(s):  
Sebastijan Veselic ◽  
Claudio Zito ◽  
Dario Farina
Keyword(s):  
Degrees Of Freedom ◽  
Linear Time ◽  
Open Loop ◽  
Human Robot Interaction ◽  
Manual Control ◽  
Reach To Grasp ◽  
Robot Interaction ◽  
Loop Control ◽  
User Awareness ◽  
Improving Accuracy

Designing robotic assistance devices for manipulation tasks is challenging. This work aims at improving accuracy and usability of physical human-robot interaction (pHRI) where a user interacts with a physical robotic device (e.g., a human operated manipulator or exoskeleton) by transmitting signals which need to be interpreted by the machine. Typically these signals are used as an open-loop control, but this approach has several limitations such as low take-up and high cognitive burden for the user. In contrast, a control framework is proposed that can respond robustly and efficiently to intentions of a user by reacting proactively to their commands. The key insight is to include context- and user-awareness in the controller, improving decision making on how to assist the user. Context-awareness is achieved by creating a set of candidate grasp targets and reach-to grasp trajectories in a cluttered scene. User-awareness is implemented as a linear time-variant feedback controller (TV-LQR) over the generated trajectories to facilitate the motion towards the most likely intention of a user. The system also dynamically recovers from incorrect predictions. Experimental results in a virtual environment of two degrees of freedom control show the capability of this approach to outperform manual control. By robustly predicting the user’s intention, the proposed controller allows the subject to achieve superhuman performance in terms of accuracy and thereby usability.

scholarly journals Motion and Trajectory Constraints Control Modeling for Flexible Surgical Robotic Systems

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 386
Author(s):  
Olatunji Mumini Omisore ◽  
Shipeng Han ◽  
Yousef Al-Handarish ◽  
Wenjing Du ◽  
Wenke Duan ◽  
...  
Keyword(s):  
Real Time ◽  
A Priori ◽  
Tumor Resection ◽  
Computational Effort ◽  
Robotic Systems ◽  
Kinematics And Dynamics ◽  
Target Point ◽  
Real Time Control ◽  
Control Models ◽  
Constraints Model

Success of the da Vinci surgical robot in the last decade has motivated the development of flexible access robots to assist clinical experts during single-port interventions of core intrabody organs. Prototypes of flexible robots have been proposed to enhance surgical tasks, such as suturing, tumor resection, and radiosurgery in human abdominal areas; nonetheless, precise constraint control models are still needed for flexible pathway navigation. In this paper, the design of a flexible snake-like robot is presented, along with the constraints model that was proposed for kinematics and dynamics control, motion trajectory planning, and obstacle avoidance during motion. Simulation of the robot and implementation of the proposed control models were done in Matlab. Several points on different circular paths were used for evaluation, and the results obtained show the model had a mean kinematic error of 0.37 ± 0.36 mm with very fast kinematics and dynamics resolution times. Furthermore, the robot’s movement was geometrically and parametrically continuous for three different trajectory cases on a circular pathway. In addition, procedures for dynamic constraint and obstacle collision detection were also proposed and validated. In the latter, a collision-avoidance scheme was kept optimal by keeping a safe distance between the robot’s links and obstacles in the workspace. Analyses of the results showed the control system was optimal in determining the necessary joint angles to reach a given target point, and motion profiles with a smooth trajectory was guaranteed, while collision with obstacles were detected a priori and avoided in close to real-time. Furthermore, the complexity and computational effort of the algorithmic models were negligibly small. Thus, the model can be used to enhance the real-time control of flexible robotic systems.

Optimization-based real-time open-loop control of an optofluidic refractive phase modulator

2019 ◽  
Vol 58 (4) ◽  
pp. 1064 ◽  
Author(s):  
Pouya Rajaeipour ◽  
Kaustubh Banerjee ◽  
Hans Zappe ◽  
Çağlar Ataman
Keyword(s):  
Real Time ◽  
Open Loop ◽  
Phase Modulator ◽  
Open Loop Control ◽  
Loop Control

Paper 16: A Preliminary Investigation into the Effects of Applying a Locking Device to a Position-Controlled Externally Powered Prosthesis

1968 ◽  
Vol 183 (10) ◽  
pp. 93-97
Author(s):  
J. M. Pottinger ◽  
N. D. Ring
Keyword(s):  
Degrees Of Freedom ◽  
Position Control ◽  
Preliminary Investigation ◽  
Open Loop ◽  
Open Loop Control ◽  
Loop Control ◽  
Time Control ◽  
Dynamic Phase ◽  
Static Phase ◽  
Powered Prosthesis

The application of position control to externally powered prosthetic arms leads to increased function and versatility when compared to a prosthetic system with open-loop control. However, various compromises are necessary owing to the limited number of available control sites. An investigation is being conducted into the possibility of combining the advantages of position control during the dynamic phase of movement with the locking facility of velocity–time control during the static phase, which leads to a larger number of available control sites and thus a greater number of degrees of freedom.

Development of NC System of the 3-PUU Parallel Machine Tool Based on PMAC

2010 ◽  
Vol 142 ◽  
pp. 233-237
Author(s):  
Hai Peng Lin ◽  
Yi Min Xu
Keyword(s):  
Machine Tool ◽  
Real Time ◽  
Degrees Of Freedom ◽  
Rocket Engine ◽  
Parallel Machine ◽  
Numerical Control ◽  
Interface Position ◽  
Loop Control ◽  
Nc System ◽  
Parallel Machine Tool

In this paper, a PUU parallel machine tool with three translational degrees of freedom (DOF) is designed which is usually used in the complex grain machining of the solid rocket engine.， and its numerical control system is described in detail. The so-called “PC+PMAC” is used as the hardware platform, and Windows as the software one, the parallel machine tool NC system is built. The features, such as multi-axis motion control and fast real time communication of PMAC, software resources and efficient data processing of PC are utilized such that Man Machine Interface, position servo control, real time measurement of cutter configuration and closed loop control of the parallel machine tool are realized.

Design and Implementation of a Kind of Intelligent Electric Blanket Temperature Control System

2013 ◽  
Vol 432 ◽  
pp. 447-452
Author(s):  
Rong Li ◽  
Zhe Ming Duan ◽  
Wei Zhou ◽  
Bing Chao Dong
Keyword(s):  
Real Time ◽  
Temperature Control ◽  
Temperature Control System ◽  
Single Chip ◽  
Real Time Control ◽  
Loop Control ◽  
Relay Control ◽  
Time Control ◽  
Control Relay ◽  
Design And Manufacture

Temperature control is the key problem in the design and manufacture of electric blankets. In order to solve current technological failure to real-time control of the temperature of electric blanket, this paper applies technical means of DS18B20 temperature acquisition and relay control temperature heating, together with key circuit, display circuit as well as other auxiliary circuit, and the system achieved electric blanket working temperature real-time intelligent control. Relay output controlled the temperature closed loop control by single-chip microcomputer, and a new type of intelligent temperature control technology of electric blanket is developed, real-time temperature control is enhanced, which improved the security and energy conservation of electric blanket.

scholarly journals Design and performance assessment of an underactuated hand for industrial applications

2011 ◽  
Vol 2 (1) ◽  
pp. 9-15 ◽  
Author(s):  
C. Meijneke ◽  
G. A. Kragten ◽  
M. Wisse
Keyword(s):  
Degrees Of Freedom ◽  
International Workshop ◽  
Input Voltage ◽  
Industrial Applications ◽  
Open Loop ◽  
Robotic Hand ◽  
Loop Control ◽  
Six Degrees Of Freedom ◽  
And Performance ◽  
Underactuated Robot

Abstract. The Delft Hand 2 (DH-2) is an underactuated robot hand meant for industrial applications, having six degrees of freedom (DoF), one actuator (DoA) and no sensors. It was designed to provide a cheap and robust hand to grasp a large range of objects without damaging them. The goal of this paper is to assess the design and performance of the DH-2, demonstrating how the design was optimized for its intended application area and how the hand was simplified to make it commercially attractive. Performance tests show that the DH-2 has a payload of 2 kg for an object range of 60 to 120 mm, it can close or open within 0.5 s, and it only uses open-loop control by means of the input voltage of the motor. The results demonstrate that the industrial need of a simple, cheap and effective robotic hand can be achieved with the principle of underactuation and the use of conventional components. This paper was presented at the IFToMM/ASME International Workshop on Underactuated Grasping (UG2010), 19 August 2010, Montréal, Canada.

scholarly journals A novel energy-motion model for continuous sEMG decoding: from muscle energy to motor pattern

2020 ◽  
Author(s):  
Gang Liu ◽  
Lu Wang ◽  
Jing Wang
Keyword(s):  
Real Time ◽  
Degrees Of Freedom ◽  
Motor Pattern ◽  
Human Hand ◽  
Motion Model ◽  
Real Time Control ◽  
Prosthetic Hands ◽  
Time Control ◽  
Energy Mode ◽  
Muscle Energy

Myoelectric prosthetic hands create the possibility for amputees to control their prosthetics like native hands. However, user acceptance of the extant myoelectric prostheses is low. Unnatural control, lack of sufficient feedback, and insufficient functionality are cited as primary reasons. Recently, although many multiple degrees-of-freedom (DOF) prosthetic hands and tactile-sensitive electronic skins have been developed, no non-invasive myoelectric interfaces can decode both forces and motions for five-fingers independently and simultaneously. This paper proposes a myoelectric interface based on energy allocation and fictitious forces hypothesis by mimicking the natural neuromuscular system. The energy-based interface uses a kind of continuous “energy mode” in the level of the entire hand. According to tasks itself, each energy mode can adaptively and simultaneously implement multiple hand motions and exerting continuous forces for a single finger. Also, a few learned energy modes could extend to the unlearned energy mode, highlighting the extensibility of this interface. We evaluate the proposed system through off-line analysis and operational experiments performed on the expression of the unlearned hand motions, the amount of finger energy, and real-time control. With active exploration, the participant was proficient at exerting just enough energy to five fingers on “fragile” or “heavy” objects independently, proportionally, and simultaneously in real-time. The main contribution of this paper is proposing the bionic energy-motion model of hand: decoding a few muscle-energy modes of the human hand (only ten modes in this paper) map massive tasks of bionic hand.

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