Trajectory planning of a 4-RR(SS)2 high-speed parallel robot

Robotica ◽  
2022 ◽  
pp. 1-17
Author(s):  
Huipu Zhang ◽  
Manxin Wang ◽  
Haibin Lai ◽  
Junpeng Huang
Keyword(s):  
Trajectory Planning ◽  
Inverse Kinematics ◽  
High Speed ◽  
Movement Time ◽  
Parallel Robot ◽  
Acceleration And Deceleration ◽  
Moving Platform ◽  
Motion Parameters ◽  
Trajectory Interpolation ◽  
The Right

Abstract The trajectory-planning method for a novel 4-degree-of-freedom high-speed parallel robot is studied herein. The robot’s motion mechanism adopts RR(SS)2 as branch chains and has a single moving platform structure. Compared with a double moving platform structure, the proposed parallel robot has better acceleration and deceleration performance since the mass of its moving platform is lighter. An inverse kinematics model of the mechanism is established, and the corresponding relationship between the motion parameters of the end-moving platform and the active arm with three end-motion laws is obtained, followed by the optimization of the motion laws by considering the motion laws’ duration and stability. A Lamé curve is used to transition the right-angled part of the traditional gate trajectory, and the parameters of the Lamé curve are optimized to achieve the shortest movement time and minimum acceleration peak. A method for solving Lamé curve trajectory interpolation points based on deduplication optimization is proposed, and a grasping frequency experiment is conducted on a robot prototype. Results show that the grasping frequency of the optimized Lamé curve prototype can be increased to 147 times/min, and its work efficiency is 54.7% higher than that obtained using the traditional Adept gate-shaped trajectory.

The Kinematic Analysis and Trajectory Planning Study of High-Speed SCARA Robot Handling Operation

2014 ◽  
Vol 687-691 ◽  
pp. 294-299 ◽  
Author(s):  
Guo Qing Ma ◽  
Zheng Lin Yu ◽  
Guo Hua Cao ◽  
Yan Bin Zheng ◽  
Li Liu
Keyword(s):  
Trajectory Planning ◽  
Inverse Kinematics ◽  
High Speed ◽  
Polynomial Interpolation ◽  
Interpolation Method ◽  
Joint Space ◽  
Parameter Design ◽  
Matlab Simulation ◽  
Scara Robot ◽  
Cubic Polynomial

Successfully developed of high-speed SCARA robot provides the possibility for fast handling. After analyzed the mechanical structure of SCARA robot, the kinematics equations were built to analyze forward and inverse kinematics problems based on modified D-H coordinate system theory. The trajectory planning was achieved by using the cubic polynomial interpolation method in joint space over the path points combined with motion parameters, the kinematics and trajectory planning were simulated by using matlab simulation platform. Simulation results show that robot parameter design is reasonable and the trajectory planning by interpolation calculation in joint space is feasible.

scholarly journals A hierarchical approach for rigid-body dynamics model simplification of a high-speed parallel robot by considering kinematics performance

2021 ◽  
Vol 104 (4) ◽  
pp. 003685042110630
Author(s):  
Jinlu Ni ◽  
Jiangping Mei ◽  
Weizhong Hu
Keyword(s):  
Rigid Body ◽  
Trajectory Planning ◽  
High Speed ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Rigid Body Dynamics ◽  
Model Simplification ◽  
Hierarchical Approach ◽  
Dynamics Model ◽  
Body Dynamics

Considering the real-time control of a high-speed parallel robot, a concise and precise dynamics model is essential for the design of the dynamics controller. However, the complete rigid-body dynamics model of parallel robots is too complex for online calculation. Therefore, a hierarchical approach for dynamics model simplification, which considers the kinematics performance, is proposed in this paper. Firstly, considering the motion smoothness of the end-effector, trajectory planning based on the workspace discretization is carried out. Then, the effects of the trajectory parameters and acceleration types on the trajectory planning are discussed. But for the fifth-order and seventh-order B-spline acceleration types, the trajectory will generate excessive deformation after trajectory planning. Therefore, a comprehensive index that considers both the motion smoothness and trajectory deformation is proposed. Finally, the dynamics model simplification method based on the combined mass distribution coefficients is studied. Results show that the hierarchical approach can guarantee both the excellent kinematics performance of the parallel robot and the accuracy of the simplified dynamics model under different trajectory parameters and acceleration types. Meanwhile, the method proposed in the paper can be applied to the design of the dynamics controller to enhance the robot's performance.

Elastic Dynamics Optimization Design of Novel High-Speed Spatial Parallel Robot

2011 ◽  
Vol 415-417 ◽  
pp. 39-42
Author(s):  
Xiu Long Chen ◽  
Shuai Shuai Jia ◽  
Chong Jie Du ◽  
Shi Bo Shen
Keyword(s):  
Theoretical Basis ◽  
High Speed ◽  
Optimization Design ◽  
Dynamic Stress ◽  
Dynamic Performance ◽  
Parallel Robot ◽  
Improve Performance ◽  
Moving Platform ◽  
Simulation Results ◽  
Elastic Dynamics

In order to improve performance of 4-UPS-RPS high-speed spatial parallel robot, the elastic dynamics optimization design was executed. The influence law of the mass of moving platform and the diameter of driving limbs on the dynamic performance, which includes kinematics output response and maximum dynamic stress of driving limbs, were discussed. On these grounds, the mass of moving platform and the diameter of driving limbs were optimized. The simulation results show obvious improvement of the dynamics performance for 4-UPS-RPS parallel robot, therefore the theoretical basis are provided.

Performance simulation and energetic analysis of TBot high-speed cable-driven parallel robot

2021 ◽  
pp. 1-14
Author(s):  
Jinhao Duan ◽  
Zhufeng Shao ◽  
Zhaokun Zhang ◽  
Fazhong Peng
Keyword(s):  
Energy Consumption ◽  
Trajectory Planning ◽  
High Speed ◽  
Low Cost ◽  
Parallel Robot ◽  
Industrial Applications ◽  
Parallel Robots ◽  
Dynamics Modeling ◽  
Serial Robots ◽  
Key Issues

Abstract Compared with serial robots, parallel robots have the advantages of high stiffness and good dynamics. By replacing the rigid limbs with cables, the cable-driven parallel robot (CDPR) is greatly simplified in structure and lightweight. We designed a high-speed CDPR tensioned by the passive rod and spring, named TBot. The robot can realize the SCARA movement as the classical Delta parallel robot. Comparison analysis of TBot and Delta is carried out to reveal the natures of the CDPRs and rigid parallel robots, identify the key issues, and promote industrial applications. Based on kinematics and dynamics modeling, performances are analyzed with simulation under a typical Adept Motion trajectory. Results illustrate that TBot has advantages of low cost, low inertia, low energy consumption and adjustable workspace and has great application potential. Energy consumption of the TBot is discussed and the trajectory planning is studied with the genetic algorithm to further reduce the energy consumption, considering the influence of the passive spring. Finally, on the basis of 30% less energy consumption for the Adept Motion than Delta, extra 14.3% energy consumption is saved through the trajectory planning of TBot.

scholarly journals Evaluation of the Period of Sensors Motion Parameters of the Train

2018 ◽  
Vol 15 (1) ◽  
Author(s):  
Petr Filimonovich Filimonovich
Keyword(s):  
Spectral Method ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Spectral Representation ◽  
High Speed Trains ◽  
Acceleration And Deceleration ◽  
Motion Parameters

The choice of polling period sensors for measuring the speed and acceleration of the train can be produced using the spectral representation of functions of velocity and acceleration from time to time. Using the spectral method of determining the period of the survey, you can choose different value depending on the category of the train and its dynamic characteristics. For high-speed trains, the period of sensors is less than for trucks, since the latter are tightened by the transients during acceleration and deceleration.

Kinematics Analysis of 6-DOF Transportation Vibration Platform

2011 ◽  
Vol 199-200 ◽  
pp. 1419-1422 ◽  
Author(s):  
Yan Zhu ◽  
Shi Shun Zhu ◽  
Guo Jun Wang ◽  
Xu Gang Liu
Keyword(s):  
System Dynamics ◽  
Trajectory Planning ◽  
Dynamics Analysis ◽  
Motion Trajectory ◽  
Kinematics Analysis ◽  
Kinematics Model ◽  
Moving Platform ◽  
Motion Parameters ◽  
Position And Orientation

Based on the principle of Space Mechanism, the kinematics model of 6-DOF transportation vibration platform is described, and system kinematics analysis and calculation are finished. With an example, the displacement of actuator is solved according to the position and orientation of moving platform. The kinematics analysis is the basis of deciding system motion parameters, motion trajectory planning and system dynamics analysis.

Task space-based dynamic trajectory planning for digging process of a hydraulic excavator with the integration of soil–bucket interaction

2018 ◽  
Vol 233 (3) ◽  
pp. 598-616 ◽  
Author(s):  
Zhihong Zou ◽  
Jin Chen ◽  
Xiaoping Pang
Keyword(s):  
Trajectory Planning ◽  
Trajectory Optimization ◽  
Inverse Kinematics ◽  
Field Experiments ◽  
Hydraulic Excavator ◽  
Task Space ◽  
Working Mechanism ◽  
Motion Parameters ◽  
Self Motion ◽  
Dynamic Trajectory

In this paper, a task space-based methodology for dynamic trajectory planning for digging process of a hydraulic excavator is presented, with the integration of soil–bucket interaction. An extended soil–bucket interaction model, which adds the resistive moment compared to the previous models, is provided in this research. This improved model is validated by comparing with the measurement data taken from field experiments before integrating it into a dynamic model of an excavator. Further, Newton–Euler method is used for the derivation of the dynamics of each link of the excavator to determine the joint forces, which can cause the machine damage. The position and orientation trajectories of the bucket in the task space are parameterized by using the B-splines, so as to achieve the task-oriented operations and ensure the operation flexibility. The joint space motion characteristics are obtained by solving the inverse kinematics of the working mechanism of an excavator. Moreover, to avoid the operation uncertainty for a given bucket tip position trajectory and reduce the computational effort, the self-motion parameters are introduced when solving the inverse kinematics of the redundant working mechanism. All these self-motion parameters are taken as a set of design variables in the trajectory optimization problem. Also, the limits on the hydraulic driving forces, joint angles, angular velocities and accelerations, as well as bucket capacity are considered as the optimization constraints for the digging process. Finally, optimization examples of two typical digging categories (i.e. level digging work and slope digging work) are given to demonstrate and verify the capabilities of the new methodology proposed in this research. The results show that the proposed method can effectively generate the optimal trajectories satisfying the following criteria: time efficiency, energy efficiency, and least machine damage. This work lays a solid foundation for motion planning and autonomous control of an excavator.

Reducing energy consumption via trajectory planning method for delta high-speed parallel manipulator

2019 ◽  
pp. 002072091989420
Author(s):  
Cheng Liu ◽  
Guohua Cao ◽  
Yongyin Qu
Keyword(s):  
Energy Consumption ◽  
Obstacle Avoidance ◽  
Trajectory Planning ◽  
High Speed ◽  
Polynomial Interpolation ◽  
Parallel Robot ◽  
Joint Space ◽  
Degree Polynomial ◽  
Operating Space ◽  
Motion Characteristics

This paper selects delta high-speed parallel robot with three degrees of freedom as the research object. The trajectory planning strategies of Cartesian space and angular displacement, angular velocity and angular acceleration of three joints in high-speed handling are studied. Firstly, the critical trajectory points starting point and end point, and points for obstacle avoidance height are set up, and then according to the inverse kinematics model of the robot, a point-to-point “door” type moving trajectory is established, and the mapping relationship between the motion characteristics of the operating space and the motion characteristics of the joint space is established by using the 4-3-4 degree polynomial motion law in the operating space. However, aiming at the higher energy consumption of 4-3-4 degree polynomial interpolation caused by longer the trajectory, and difficult control of obstacle avoidance height, one key point is added. Thereby, the motion rules are interpolated by 4-3-3-4 degree polynomial interpolation, and the mapping relationship between the motion characteristics of the operating space and the motion characteristics of the joint space is established. Two trajectory planning methods are simultaneously simulated under the same keys points and the same trajectory time range. The motion characteristics of the joint rotation angle of the parallel robot between polynomial interpolations are respectively compared. The results show that the trajectory planning method based on 4-3-3-4 degree polynomial interpolation in joint space has obvious advantages in improving the running state of the delta parallel robot and reducing the energy consumption of the system.

Exploiting the Kinematic Redundancy of a 6+3 Dofs Parallel Mechanism

2018 ◽  
Author(s):  
Louis-Thomas Schreiber ◽  
Clément Gosselin
Keyword(s):  
Trajectory Planning ◽  
Inverse Kinematics ◽  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Stewart Platform ◽  
Kinematic Redundancy ◽  
Compressive Loads ◽  
Planning Methods ◽  
Moving Platform

This paper presents trajectory planning methods for a kinematically redundant parallel mechanism. The architecture of the mechanism is similar to the well-known Gough-Stewart platform and it retains its advantages, i.e., the members connecting the base to the moving platform are only subjected to tensile/compressive loads. The kinematic redundancy is exploited to avoid singularities and extend the rotational workspace. The architecture is described and the associated kinematic relationships are presented. Solutions for the inverse kinematics are given, as well as strategies to take into account the limitations of the mechanism such as mechanical interferences and velocity limits of the actuators while controlling the redundant degrees of freedom.

Influence of social media marketing towards purchase of residential property

2019 ◽  
Vol 118 (6) ◽  
pp. 145-149
Author(s):  
A. Ekanthalingam ◽  
Dr. A. Gopinath
Keyword(s):  
Social Media ◽  
High Speed ◽  
Word Of Mouth ◽  
Marketing Strategies ◽  
Social Media Marketing ◽  
Purchase Decision ◽  
Residential Property ◽  
Customer Delight ◽  
The Right ◽  
Potential Customers

‘Marketing’ is not just an activity. It is a process, a philosophy and a phenomenon. The evolution of marketing has produced tremendous benefits to business and end consumers. The innovation in this field has been steady and yet at high speed. From ‘word of mouth advertising’ which was the only option earlier we are now at the mercy of what consumers are sharing about their experience on the internet. Social Media has become more powerful than what we think and this article shows how we can leverage this to benefit the top-line and customer delight. We dive deep to understand the influence Social Media can create towards purchase of residential property. As much complex it is to make the purchase decision of a property, it is equally difficult for marketers to send the right message to their target audience. Through this article, we are trying to see how marketers have transformed their traditional marketing strategies to address the needs of the millennial population, who are the most potential customers for property purchase.

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