scholarly journals Trajectory control and parameter optimization of plasma robot gun

2020 ◽  
Vol 24 (3 Part A) ◽  
pp. 1819-1825
Author(s):  
Xiaohua Chen ◽  
Zhanshan Wang ◽  
Kailei Liu
Keyword(s):  
Trajectory Optimization ◽  
Degrees Of Freedom ◽  
Fitness Function ◽  
Optimal Solution ◽  
Joint Space ◽  
Working Environment ◽  
Motion Characteristics ◽  
Set Up ◽  
Working Parameters ◽  
Spray Gun

A plasma robot model with redundant freedom is proposed for the shortage of flexibility in the complex working environment of plasma robot. The existence of redundant degrees of freedom leads to the complex motion characteristics of the plasma robot joints. The trajectory of the end of the spray gun is difficult to describe. Therefore, a trajectory optimization algorithm based on fitness function is proposed. In the plasma robot joint space, a parabolic linear fitting is adopted. The error between the actual trajectory and the desired trajectory is taken as fitness function. Genetic algorithm is applied to find the optimal solution for the parameters in trajectory planning. The orthogonal experimental model of the parameters of the plasma spray gun is set up. The optimum working parameters of the spray gun are obtained through the analysis and study of the power, atmospheric pressure and the distance of the gun. Finally, the rationality of the proposed method is proved by simulation and test.

Multi-Objective Trajectory Optimization of Free-Floating Space Manipulator Using NSGA-II

2015 ◽  
Vol 713-715 ◽  
pp. 800-804 ◽  
Author(s):  
Gang Chen ◽  
Cong Wei ◽  
Qing Xuan Jia ◽  
Han Xu Sun ◽  
Bo Yang Yu
Keyword(s):  
Trajectory Optimization ◽  
Interpolation Method ◽  
Optimal Solution ◽  
Optimization Method ◽  
Joint Space ◽  
Motion Path ◽  
Objective Functions ◽  
Nsga Ii ◽  
Space Manipulator ◽  
Multi Objective

In this paper, a kind of multi-objective trajectory optimization method based on non-dominated sorting genetic algorithm II (NSGA-II) is proposed for free-floating space manipulator. The aim is to optimize the motion path of the space manipulator with joint angle constraints and joint velocity constraints. Firstly, the kinematics and dynamics model are built. Secondly, the 3-5-3 piecewise polynomial is selected as interpolation method for trajectory planning of joint space. Thirdly, three objective functions are established to simultaneously minimize execution time, energy consumption and jerk of the joints. At last, the objective functions are combined with the NSGA-II algorithm to get the Pareto optimal solution set. The effectiveness of the mentioned method is verified by simulations.

LOWER LIMB REHABILITATION ROBOT FOR GAIT TRAINING

2014 ◽  
Vol 14 (06) ◽  
pp. 1440004 ◽  
Author(s):  
SHUAI GUO ◽  
JIANCHENG JI ◽  
GUANGWEI MA ◽  
TAO SONG ◽  
JING WANG
Keyword(s):  
Lower Limb ◽  
Degrees Of Freedom ◽  
Balance Training ◽  
Gait Training ◽  
Rehabilitation Robot ◽  
Stroke Patients ◽  
Motion Characteristics ◽  
Set Up ◽  
Limb Rehabilitation ◽  
Lower Limb Rehabilitation

After analyzing the rehabilitation needs of stroke patients and the previous studies on lower limb rehabilitation robot, our lower limb rehabilitation robot is designed for stroke patients' gait and balance training. The robot consists of the mobile chassis, the support column and the pelvis mechanism and it is described in detail. As the pelvis mechanism allows most of the patient's motion degrees of freedom (DOFs), the kinematics model of the mechanism is set up, and kinematics simulation is carried out to study the motion characteristics of the mechanism. After analyzing the calculation and simulation results, the pelvis mechanism is proven to measure up to the movement needs of the paralytic's waist and pelvis in walking rehabilitation process.

scholarly journals Trajectory Optimization Algorithm for a 4-DOF Redundant Parallel Robot Based on 12-Phase Sine Jerk Motion Profile

Actuators ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 80
Author(s):  
Shengqiao Hu ◽  
Huimin Kang ◽  
Hao Tang ◽  
Zhengjie Cui ◽  
Zhicheng Liu ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Trajectory Optimization ◽  
High Speed ◽  
Degrees Of Freedom ◽  
Sudden Change ◽  
Parallel Robot ◽  
Joint Space ◽  
Allowable Limit ◽  
Three Phase ◽  
Motion Profile

To improve high motion accuracy and efficiency in the high-speed operation of a 4-DOF (4 degrees of freedom) redundant parallel robot, this paper introduces a trajectory planning of the parallel robot in joint space based on the twelve-phase sine jerk motion profile. The 12-phase sine jerk motion profile utilizes the characteristics of a sine function. Furthermore, the penalty function is used to optimize the trajectory energy consumption under the constraint condition. The simulation and experimental results show that the energy consumption of joint space is slightly higher than that of the three-phase sine jerk motion profile, but the overall operation is more accurate and stable. Specifically, the sudden change of force and velocity in each joint is eliminated, which is the cause of mechanism oscillation. Moreover, the force of each joint is more average. The results indicate that each movement is closer to the maximum allowable limit and the running efficiency is higher.

Multivariable Extremum Seeking for Joint-Space Trajectory Optimization of a High-Degrees-of-Freedom Robot

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Mostafa Bagheri ◽  
Miroslav Krstić ◽  
Peiman Naseradinmousavi
Keyword(s):  
Trajectory Optimization ◽  
Degrees Of Freedom ◽  
Research Effort ◽  
Minimum Energy ◽  
Joint Space ◽  
Design Sensitivity ◽  
Extremum Seeking ◽  
Minimum Energy Consumption ◽  
Gradient Based ◽  
The Cost

In this paper, a novel analytical coupled trajectory optimization of a seven degrees-of-freedom (7DOF) Baxter manipulator utilizing extremum seeking (ES) approach is presented. The robotic manipulators are used in network-based industrial units, and even homes, by expending a significant lumped amount of energy, and therefore, optimal trajectories need to be generated to address efficiency issues. These robots are typically operated for thousands of cycles resulting in a considerable cost of operation. First, coupled dynamic equations are derived using the Lagrangian method and experimentally validated to examine the accuracy of the model. Then, global design sensitivity analysis is performed to investigate the effects of changes of optimization variables on the cost function leading to select the most effective ones. We examine a discrete-time multivariable gradient-based ES scheme enforcing operational time and torque saturation constraints in order to minimize the lumped amount of energy consumed in a path given; therefore, time-energy optimization would not be the immediate focus of this research effort. The results are compared with those of a global heuristic genetic algorithm (GA) to discuss the locality/globality of optimal solutions. Finally, the optimal trajectory is experimentally implemented to be thoroughly compared with the inefficient one. The results reveal that the proposed scheme yields the minimum energy consumption in addition to overcoming the robot's jerky motion observed in an inefficient path.

scholarly journals Using FPGA Design and HIL Algorithm Simulation to Control Visual Servoing

2018 ◽  
Vol 6 (2) ◽  
pp. 111
Author(s):  
Lway Faisal Abdulrazak ◽  
Zaid A. Aljawary
Keyword(s):  
Object Tracking ◽  
Visual Servoing ◽  
Degrees Of Freedom ◽  
Optimal Solution ◽  
Robot Dynamics ◽  
Fpga Design ◽  
Joint Torques ◽  
Array Technology ◽  
Gate Array ◽  
Set Up

<span style="font-size: 9pt; font-family: 'Times New Roman', serif;">This is a novel research paper provides an optimal solution for object tracking using visual servoing control system with programmable gate array technology to realize the visual controller. The controller takes in account the robot dynamics to generate the joint torques directly for performing the tasks related to object tracking using visual servoing. Also, the notion of dynamic perceptibility provides the capability of the designed system to track desired objects employing direct visual servoing technique. This idea is assimilated in the suggested controller and realized in the programmable gate array. Additionally, this paper grants an ideal control framework for direct visual servoing robots that incorporates dynamic perceptibility features. With the aim of evaluating the proposed FPGA based architecture, the control algorithm is applied to Hardware-in-the-loop simulation (HIL) set up of three degrees of freedom rigid robotic manipulator with three links. Furthermore, different investigations are performed to demonstrate the behavior of the proposed system when a trajectory adjacent to a singularity is attained.</span>

scholarly journals Optimization of Fuzzy Logic Based Virtual Pilot for Wargaming

Mathematics ◽  
2021 ◽  
Vol 9 (24) ◽  
pp. 3169
Author(s):  
Alexandr Stefek ◽  
Petr Frantis
Keyword(s):  
Degrees Of Freedom ◽  
Fitness Function ◽  
Optimal Solution ◽  
Optimization Process ◽  
Membership Functions ◽  
Fuzzy Controllers ◽  
Engine Thrust ◽  
Input Variables ◽  
6 Degrees Of Freedom ◽  
Simulation Parameters

This paper deals with the design of an autopilot based on a set of fuzzy controllers. The model of the aircraft that the autopilot controls is defined as a model with 6 degrees of freedom, where the inputs to this model are the settings of the engine thrust (DX), rudder rotation (Dl) and elevators (Dm and Dn). The fuzzy controllers are of the Mamdani type, where the set of parameters defining the controller allow the derivation of membership functions of the input variables and membership functions of the output variables. The parameters of fuzzy controllers are determined by the optimization process. For the purpose of optimization, a fitness function is defined, which derives the simulation parameters from its parameter (vector), and the simulation subsequently performed and evaluated determines whether it is a feasible solution in addition the value of this solution. By this optimization process, the sub-optimal solution is found and is then used to define the settings of the fuzzy controllers and, therefore, the autopilot. This paper contains a description of each step of the solution of the described problem, and with the help of the obtained results, it is determined that the presented procedure allows us to find an autopilot capable of controlling the defined model of the aircraft. In addition, there is a brief description regarding the misconceptions explored during the development of the experiment.

Kinematics of a Hybrid Series-Parallel Manipulation System

1989 ◽  
Vol 111 (2) ◽  
pp. 211-221 ◽  
Author(s):  
K. J. Waldron ◽  
M. Raghavan ◽  
B. Roth
Keyword(s):  
Degrees Of Freedom ◽  
Joint Space ◽  
Degree Of Freedom ◽  
Micro Manipulator ◽  
In Series ◽  
Basic Transformation ◽  
Motion Characteristics ◽  
Six Degree Of Freedom ◽  
Three Degree Of Freedom ◽  
Force Decomposition

In this paper we first derive the coordinate transformations associated with a three-degree-of-freedom in-parallel-actuated micro-manipulator. Then we combine these results with the transformations associated with an in-series three-axis wrist on which the in-parallel micro-manipulator is mounted. The results are the basic transformation equations between joint-space position variables and end-effector (or task space) position variables for a hybrid series/parallel six-degree-of-freedom manipulator system. This structural combination results in a manipulator which exhibits desirable fine and gross motion characteristics as both a stand-alone device or as a sub-system of a more complex system with redundant degrees of freedom. The forward and inverse position kinematics and rate and force decomposition for this hybrid six-degree-of-freedom linkage are presented.

scholarly journals Using FPGA Design and HIL Algorithm Simulation to Control Visual Servoing

2018 ◽  
Vol 7 (2) ◽  
pp. 168
Author(s):  
Lway Faisal Abdulrazak ◽  
Zaid A. Aljawary
Keyword(s):  
Object Tracking ◽  
Visual Servoing ◽  
Degrees Of Freedom ◽  
Optimal Solution ◽  
Robot Dynamics ◽  
Fpga Design ◽  
Joint Torques ◽  
Array Technology ◽  
Gate Array ◽  
Set Up

<span lang="EN-US">This is a novel research paper provides an optimal solution for object tracking using visual servoing control system with programmable gate array technology to realize the visual controller. The controller takes in account the robot dynamics to generate the joint torques directly for performing the tasks related to object tracking using visual servoing. Also, the notion of dynamic perceptibility provides the capability of the designed system to track desired objects employing direct visual servoing technique. This idea is assimilated in the suggested controller and realized in the programmable gate array. Additionally, this paper grants an ideal control framework for direct visual servoing robots that incorporates dynamic perceptibility features. With the aim of evaluating the proposed FPGA based architecture, the control algorithm is applied to Hardware-in-the-loop simulation (HIL) set up of three degrees of freedom rigid robotic manipulator with three links. Furthermore, different investigations are performed to demonstrate the behavior of the proposed system when a trajectory adjacent to a singularity is attained.</span>

Collision-Free Path Planning for Mobile Cranes Based on Ant Colony Algorithm

2011 ◽  
Vol 467-469 ◽  
pp. 1108-1115 ◽  
Author(s):  
Xin Wang ◽  
Y.Y. Zhang ◽  
Di Wu ◽  
Shun De Gao
Keyword(s):  
Path Planning ◽  
Free Path ◽  
Degrees Of Freedom ◽  
Ant Colony Algorithm ◽  
Engineering Application ◽  
Optimal Solution ◽  
Ant Colony ◽  
Working Environment ◽  
Full Account ◽  
Comparison Results

This paper presents the work done towards searching a collision-free path for mobile crane based on C-space in the complex 3D working environment. The crane is simplified into three degrees of freedom (DOFs) robot, each of which is represented as an axis of configuration space (C-space). In this paper, we propose an improved ant colony approach for crane path planning, which takes into full account of not only the factor of the shortest path but also the factor of safety. In this approach, we employ more complete heuristic information, introduce adaptive pheromone volatilization coefficient and pheromone penalty factors, and prevent ants from falling into trap and the stagnation. The reasonability and practicability of the proposed approach for automated path planning is verified by comparing the performances of the present approaches in the practice case, and the comparison results show that the algorithm can gain a relatively optimal solution in short time and have a great value of engineering application.

scholarly journals A Position-Level Global Optimization Inverse Kinematic Solution Algorithm for Dual Redundant Robots Based on Motion Characteristics

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Jingjie He
Keyword(s):  
Degrees Of Freedom ◽  
Optimal Solution ◽  
Inverse Kinematic ◽  
Motion Path ◽  
Camera Motion ◽  
Global Optimal Solution ◽  
Redundant Robots ◽  
Global Optimal ◽  
Motion Characteristics ◽  
Kinematic Solution

Camera robot is an important tool for realizing and reproducing complex camera motion path in modern special film effects. This paper proposed an inverse kinematics optimization algorithm for PRRPR-S redundant degrees of freedom (DoF) camera robot. This paper analyzed the motion characteristics, in Genetic Mix (GM) method, from the idea of movement boundary composed of part robot axis. Then proposed Simplify Mix (SM) method which can stably converge to the global optimal solution in a shorter time.

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