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.

An Operations Research Approach to Work-Optimal Trajectories for Redundant Robotic Manipulators

2011 ◽  
Author(s):  
John Steuben ◽  
Paul Brayford ◽  
Cameron J. Turner
Keyword(s):  
Infinite Number ◽  
Operations Research ◽  
Degrees Of Freedom ◽  
Minimum Energy ◽  
Robotic Manipulators ◽  
Joint Space ◽  
Research Approach ◽  
Robotic Welding ◽  
Minimum Energy Consumption ◽  
Visualization Tools

Control of redundant robotic manipulators has proven to be troublesome in the past. Redundant manipulators exhibit more degrees of freedom than there are constraints on their pose. As a result the robot’s kinematics are non-deterministic, and an infinite number of robot poses satisfy any given set of constraints. Thus there are an infinite number of paths that a robot may take whilst following a trajectory planned in Cartesian space (as opposed to joint space). We present a trajectory following method for a redundant welding robot with nine degrees of freedom (DOF). A powerful modeling tool widely used in operations research, AMPL, is leveraged to this end. The paths developed for the 9-DOF robot are optimized for minimum energy consumption by the robot motors. We also demonstrate a simulated robot work cell which is used to visualize and demonstrate the paths produced in this manner. Common robotic welding tasks are used to demonstrate the effectiveness of these optimization and visualization tools. We conclude with a discussion of the computational efficiency and limitations of this new method, and highlight several paths forward for this line of research.

From Construction to Operation: Achieving Indoor Thermal Comfort via Altering External Walls Specifications in Egypt

2013 ◽  
Vol 689 ◽  
pp. 250-253 ◽  
Author(s):  
Mohamed M. Mahdy ◽  
Marialena Nikolopoulou
Keyword(s):  
Energy Consumption ◽  
Thermal Comfort ◽  
Natural Ventilation ◽  
Minimum Energy ◽  
Residential Energy ◽  
Indoor Thermal Comfort ◽  
Minimum Energy Consumption ◽  
Different Types ◽  
Running Cost ◽  
The Cost

The objective of this research is to study the effect of using different material specifications for the external walls on the cost of the energy consumption for achieving internal thermal comfort. We refer to this as operation running cost, which in turn is compared to initial construction cost for each type of the used external walls. In order to achieve this objective, dynamic thermal simulation were carried out for four different types of external walls – commonly used in Egypt – in two different sets of cooling: natural ventilation and mechanical means. Experiments recommend that using the Egyptian Residential Energy Code (EREC) to achieve inner thermal comfort with the minimum energy consumption (consequently the minimum CO2 emissions) and the minimum running cost as well.

Experimental and Novel Analytical Trajectory Optimization of a 7-DOF Baxter Robot: Global Design Sensitivity and Step Size Analyses

2017 ◽  
Author(s):  
Mostafa Bagheri ◽  
Peiman Naseradinmousavi ◽  
Rasha Morsi
Keyword(s):  
Global Optimization ◽  
Cost Function ◽  
Trajectory Optimization ◽  
Computational Cost ◽  
Joint Space ◽  
Design Sensitivity ◽  
Target Object ◽  
Size Analysis ◽  
Step Size ◽  
Novel Approach

In this paper, we present a novel nonlinear analytical coupled trajectory optimization of a 7-DOF Baxter manipulator validated through experimental work utilizing global optimization tools. The robotic manipulators used in network-based applications of industrial units and even homes, for disabled patients, spend significant lumped amount of energy and therefore, optimal trajectories need to be generated to address efficiency issues. We here examine both heuristic (Genetics) and gradient based (GlobalSearch) algorithms for a novel approach of “S-Shaped” trajectory (unlike conventional polynomials), to avoid being trapped in several possible local minima along with yielding minimal computational cost, enforcing operational time and torque saturation constraints. The global schemes are utilized in minimizing the lumped amount of energy consumed in a nominal path given in the collision-free joint space except an impact between the robot’s end effector and a target object for the nominal operation. Note that such robots are typically operated for thousands of cycles resulting in a considerable cost of operation. Due to the expected computational cost of such global optimization algorithms, step size analysis is carried out to minimize both the computational cost (iteration) and possibly cost function by finding an optimal step size. Global design sensitivity analysis is also performed to examine the effects of changes of optimization variables on the cost function defined.

Minimum Energy Control of Redundant Linear Manipulators

2014 ◽  
Vol 136 (5) ◽  
Author(s):  
Yoram Halevi ◽  
Emanuele Carpanzano ◽  
Giuseppe Montalbano
Keyword(s):  
Energy Consumption ◽  
Degrees Of Freedom ◽  
Minimum Energy ◽  
Input Voltage ◽  
Joint Motion ◽  
End Effector ◽  
Minimum Energy Control ◽  
The Individual ◽  
The Cost ◽  
Exact Energy

In redundant manipulation systems, the end-effector path does not completely determine the trajectories of all the individual degrees of freedom (dof) and the additional dofs can be used to enhance the performance in some sense. The paper deals with utilizing the redundancy to minimize energy consumption. A full linear electromechanical model is used, and the exact energy consumption is calculated. The optimization includes also displacement limits via penalty functions that are included in the cost function. The optimal trajectory is feasible in the sense that it can be obtained by a finite input voltage and all the velocities are continuous. The solution is based on projections that separate the system and the input into two parts. One that is completely determined by the end-effector path and the other that is free for optimization. The important and delicate issue of boundary conditions is resolved accordingly. Simulation results show that redundancy, even with limited joint motion, can lead to a considerable reduction in energy consumption.

scholarly journals Bucket Trajectory Optimization under the Automatic Scooping of LHD

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3919
Author(s):  
Yu Meng ◽  
Huazhen Fang ◽  
Guodong Liang ◽  
Qing Gu ◽  
Li Liu
Keyword(s):  
Energy Consumption ◽  
Trajectory Optimization ◽  
Reaction Force ◽  
Minimum Energy ◽  
Earth Pressure ◽  
Force Model ◽  
Minimum Energy Consumption ◽  
One Step ◽  
The One ◽  
Step Step

We propose an optimal planning scheme of the bucket trajectory in the LHD (Load-Haul-Dump) automatic shoveling system to improve the effectiveness of the scooping operation. The research involves simulation of four typical shoveling methods, optimization of the scooping trajectory, establishment of a reaction force model in the scooping process and determination of optimal trajectory. Firstly, we compared the one-step, step-by-step, excavation and coordinated shoveling method by the Engineering Discrete Element Method (EDEM) simulation. The coordinated shoveling method becomes the best choice on account of its best comprehensive performance among the four methods. Based on the coordinated shoveling method, the shape of the optimized trajectory can be roughly determined. Then, we established a model of bucket force during the shoveling process by applying Coulomb’s passive earth pressure theory for the purpose of calculating energy consumption. The trajectory is finally determined through optimizing the minimum energy consumption in theory. The theoretical value is verified by the EDEM simulation.

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.

Minimum Energy Control of Redundant Cartesian Manipulators

2012 ◽  
Author(s):  
Yoram Halevi ◽  
Emanuele Carpanzano ◽  
Giuseppe Montalbano
Keyword(s):  
Degrees Of Freedom ◽  
Minimum Energy ◽  
Joint Motion ◽  
Energy Control ◽  
End Effector ◽  
Considerable Saving ◽  
Minimum Energy Control ◽  
Simulation Results ◽  
The Individual ◽  
The Cost

In redundant manipulation systems the end-effector path does not completely determine the trajectories of all the individual degrees of freedom (dof). The redundancy is used in this paper to minimize energy consumption. A full electromechanical model is used, and the invested energy is calculated explicitly. The optimization includes also displacement limits via penalty functions that are included in the cost function. The solution is based on separating the system and the input into two parts. One that is completely determined by the end-effector path and the other that is driven by it, yet free for optimization. The boundary conditions are resolved in a similar manner, where the physical values are translated to the scaled down system by using a specific projection. Simulation results show that even with limited joint motion, the redundancy can lead to a considerable saving in energy.

scholarly journals Tracking the Minimum Energy Consumption for the Lighting System though Modified Extremum Seeking Method

2017 ◽  
Vol 105 ◽  
pp. 2583-2588 ◽  
Author(s):  
Chun Yin ◽  
Shiwei Zhou ◽  
Shanshan Wu ◽  
Wei Wang ◽  
Xiuling Wei ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Minimum Energy ◽  
Extremum Seeking ◽  
Lighting System ◽  
Minimum Energy Consumption
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