Changwu Qiu - Profile on Academia.edu (original) (raw)
Papers by Changwu Qiu
Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences, 2001
Consider a system of rigid bodies with multiple concurrent contacts. The multi-rigidbody contact ... more Consider a system of rigid bodies with multiple concurrent contacts. The multi-rigidbody contact problem is to predict the accelerations of the bodies and the normal and friction loads acting at the contacts. This paper presents theoretical results for the multi-rigid-body contact problem under the assumptions that one or more contacts occur over locally planar, finite regions and that friction forces are consistent with the maximum work inequality. Existence and uniqueness results are presented for this problem under mild assumptions on the system inputs. In addition, the performance of two different time-stepping methods for integrating the dynamics are compared on two simple problems.
Graphical Programming, Simulation and Control System for Dual-Arm Mobile Robot
Computer Simulation, 2006
A graphical programming, simulation and control system is described which can provide Dual-Arm ro... more A graphical programming, simulation and control system is described which can provide Dual-Arm robot a task planning, 3D simulation and control environment. User can program a Dual-arm robot through graphical programming, preview and check motion simulation in 3D simulation, and then download optimal program to actual robot controller to ensure the desired results. The system uses Java3D and VRML for 3D simulation, and runs on RT-Linux platform to ensure Real-Time in simulation and control. Multi-robot mechanism is realized to support pipelining work or cooperation between robots. This system now supports Dual-Arm Mobile robot of YASWAKA Electric Corporation.
Resolve redundancy with constraints for obstacle and singularity avoidance subgoals
International Journal of Robotics and Automation, 2008
In this work we analyse the general form solution of the Inverse Redundant Kinematics (IRK) probl... more In this work we analyse the general form solution of the Inverse Redundant Kinematics (IRK) problem from a geometric point of view. We propose two new methods, Velocity Projection Constraints Method (VPCM) and On-line Task Modification Method (OTMM), which formulate the obstacle and singularity avoidance as constraints, and will be incorporated in the standard Quadratic Programming (QP) method to resolve the IRK problem. This will avoid the compromise or conflict between weighted optimization criteria for the obstacle and singularity avoidance subgoals, as well as the complicated weight adjustment process. The OTMM is effective not only to redundant manipulators but also to nonredundant manipulators. Numerical simulation examples validate and prove the effectiveness of the proposed methods.
Multi-objective Planning of Continuous Trajectory Taskfor an Omni-directional Mobile Dual-Arm Robot Based on Product Arbitration
Robot, 2013
Multi-objective Programming with Product Arbitration and a New Particle Swarm Optimization Algorithm
Robot, 2013
On-line planning of nonholonomic mobile manipulators based on stability twist constraint
Graphical Programming, Simulation and Control System for Dual-Arm Mobile Robot
This paper firstly presents a method to formulate the dynamics of the mobile humanoid robot which... more This paper firstly presents a method to formulate the dynamics of the mobile humanoid robot which is composed by the mobile platform and the upper body. As tip-over is an important stable issue for the mobile robot, the dynamic stability constraint is carefully studied to keep the robot stable. Stable support for the robot moving on a plane is solved. With the consideration of the stability problem during the solution of inverse kinematics, the tip-over preventing constraint is applied to get the optimized solution. Finally computer simulations are carried out with and without the consideration of tip-over preventing constraints respectively.
Redundant Manipulator Control with Constraints for Subgoals
This work analysed the general form of solution for inverse redundant kinematics (IRK) problem in... more This work analysed the general form of solution for inverse redundant kinematics (IRK) problem in geometry view, and proposed new methods to formulate the obstacle and singularity avoidance as constraints, which were incorporated into standard non-linear quadratic programming (QP) method to resolve the IRK problem. With this method, the compromise or conflict between multi optimization criteria and the complicated weighted adjustment process in weighted sum method for IRK were removed. Obstacle avoidance and physical limits, such as joint range, velocity and acceleration, were formulated as dynamic inequality constraints. For on-line inescapable singularity avoidance, the vector, according to the minimum singular value of the Jacobian matrix, was used to revise the desired tracking velocity when manipulators move near to singularity. Numerical examples show the validity and effectiveness of the proposed methods
An on-line task modification method for singularity avoidance of robot manipulators
Robotica, 2009
Improving the stability level for on-line planning of mobile manipulators
Robotica, 2009
This paper presents a quadratic programming (QP) form algorithm to realize on-line planning of mo... more This paper presents a quadratic programming (QP) form algorithm to realize on-line planning of mobile manipulators with consideration for improving the stability level. With Lie group and screw tools, the general tree topology structure mobile robot dynamics and dynamic stability attributes were analysed. The stable support condition for a mobile robot is constructed not only in a polygonal support region, but also in a polyhedral support region. For a planar supporting region, the tip-over avoiding requirement is formulated as the tip-over prevent constraints with the reciprocal products of the resultant support wrench and the imaginary tip-over twists, which are constructed with the boundaries of the convex support polygon. At velocity level, the optimized resolution algorithm with standard QP form is designed to resolve the inverse redundant kinematics of the Omni-directional Mobile ManipulatorS (OMMS) with stability considerations. Numerical simulation results show that the presented methods successfully improve the stability level of the robot within an on-line planning process.(Received June 02 2008)(Online publication July 09 2008)
Journal of Intelligent and Robotic Systems, 2008
This work studies the dynamic modeling method for a service robot with Omni-directional Mobile Ma... more This work studies the dynamic modeling method for a service robot with Omni-directional Mobile ManipulatorS configuration. Based on screw theory, Lie group notations, reciprocal product of twist and wrench, and Jourdain principle, the robot’s motion equations including the whole body manipulation are formulated with left invariant representation. A legible and canonical dynamic model representing the relation between the inputs and the generalized dynamic load wrenches is presented. Considering the tradeoff between the symbolic concision, the modularization in code realization and the computation load, the dynamic model is decomposed into succinct block factorizations, and the basic computation unites are boiled down to the adjoint map corresponding to each joint. The traditional Lie bracket operation is extended to a generalized form. Computation efficiency, for the coefficient matrixes of the system motion equation, is discussed based on its special representation form. The generalization of the modeling method with Lie group and algebra tool is also summarized.
Consider a system of rigid bodies with multiple concurrent contacts. The multi-rigid-body contact... more Consider a system of rigid bodies with multiple concurrent contacts. The multi-rigid-body contact problem is to predict the accelerations of the bodies and the normal friction loads acting at the contacts. This paper presents theoretical results for the multi-rigid-body contact problem under the assumptions that one or more contacts occur over locally planar, finite regions and that friction forces are consistent with the maximum work inequality. Existence and uniqueness results are presented for this problem under mild assumptions on the system inputs. In addition, the performance of two different time-stepping methods for integrating the dynamics are compared on two simple multi-body systems.
Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences, 2001
Consider a system of rigid bodies with multiple concurrent contacts. The multi-rigidbody contact ... more Consider a system of rigid bodies with multiple concurrent contacts. The multi-rigidbody contact problem is to predict the accelerations of the bodies and the normal and friction loads acting at the contacts. This paper presents theoretical results for the multi-rigid-body contact problem under the assumptions that one or more contacts occur over locally planar, finite regions and that friction forces are consistent with the maximum work inequality. Existence and uniqueness results are presented for this problem under mild assumptions on the system inputs. In addition, the performance of two different time-stepping methods for integrating the dynamics are compared on two simple problems.
Graphical Programming, Simulation and Control System for Dual-Arm Mobile Robot
Computer Simulation, 2006
A graphical programming, simulation and control system is described which can provide Dual-Arm ro... more A graphical programming, simulation and control system is described which can provide Dual-Arm robot a task planning, 3D simulation and control environment. User can program a Dual-arm robot through graphical programming, preview and check motion simulation in 3D simulation, and then download optimal program to actual robot controller to ensure the desired results. The system uses Java3D and VRML for 3D simulation, and runs on RT-Linux platform to ensure Real-Time in simulation and control. Multi-robot mechanism is realized to support pipelining work or cooperation between robots. This system now supports Dual-Arm Mobile robot of YASWAKA Electric Corporation.
Resolve redundancy with constraints for obstacle and singularity avoidance subgoals
International Journal of Robotics and Automation, 2008
In this work we analyse the general form solution of the Inverse Redundant Kinematics (IRK) probl... more In this work we analyse the general form solution of the Inverse Redundant Kinematics (IRK) problem from a geometric point of view. We propose two new methods, Velocity Projection Constraints Method (VPCM) and On-line Task Modification Method (OTMM), which formulate the obstacle and singularity avoidance as constraints, and will be incorporated in the standard Quadratic Programming (QP) method to resolve the IRK problem. This will avoid the compromise or conflict between weighted optimization criteria for the obstacle and singularity avoidance subgoals, as well as the complicated weight adjustment process. The OTMM is effective not only to redundant manipulators but also to nonredundant manipulators. Numerical simulation examples validate and prove the effectiveness of the proposed methods.
Multi-objective Planning of Continuous Trajectory Taskfor an Omni-directional Mobile Dual-Arm Robot Based on Product Arbitration
Robot, 2013
Multi-objective Programming with Product Arbitration and a New Particle Swarm Optimization Algorithm
Robot, 2013
On-line planning of nonholonomic mobile manipulators based on stability twist constraint
Graphical Programming, Simulation and Control System for Dual-Arm Mobile Robot
This paper firstly presents a method to formulate the dynamics of the mobile humanoid robot which... more This paper firstly presents a method to formulate the dynamics of the mobile humanoid robot which is composed by the mobile platform and the upper body. As tip-over is an important stable issue for the mobile robot, the dynamic stability constraint is carefully studied to keep the robot stable. Stable support for the robot moving on a plane is solved. With the consideration of the stability problem during the solution of inverse kinematics, the tip-over preventing constraint is applied to get the optimized solution. Finally computer simulations are carried out with and without the consideration of tip-over preventing constraints respectively.
Redundant Manipulator Control with Constraints for Subgoals
This work analysed the general form of solution for inverse redundant kinematics (IRK) problem in... more This work analysed the general form of solution for inverse redundant kinematics (IRK) problem in geometry view, and proposed new methods to formulate the obstacle and singularity avoidance as constraints, which were incorporated into standard non-linear quadratic programming (QP) method to resolve the IRK problem. With this method, the compromise or conflict between multi optimization criteria and the complicated weighted adjustment process in weighted sum method for IRK were removed. Obstacle avoidance and physical limits, such as joint range, velocity and acceleration, were formulated as dynamic inequality constraints. For on-line inescapable singularity avoidance, the vector, according to the minimum singular value of the Jacobian matrix, was used to revise the desired tracking velocity when manipulators move near to singularity. Numerical examples show the validity and effectiveness of the proposed methods
An on-line task modification method for singularity avoidance of robot manipulators
Robotica, 2009
Improving the stability level for on-line planning of mobile manipulators
Robotica, 2009
This paper presents a quadratic programming (QP) form algorithm to realize on-line planning of mo... more This paper presents a quadratic programming (QP) form algorithm to realize on-line planning of mobile manipulators with consideration for improving the stability level. With Lie group and screw tools, the general tree topology structure mobile robot dynamics and dynamic stability attributes were analysed. The stable support condition for a mobile robot is constructed not only in a polygonal support region, but also in a polyhedral support region. For a planar supporting region, the tip-over avoiding requirement is formulated as the tip-over prevent constraints with the reciprocal products of the resultant support wrench and the imaginary tip-over twists, which are constructed with the boundaries of the convex support polygon. At velocity level, the optimized resolution algorithm with standard QP form is designed to resolve the inverse redundant kinematics of the Omni-directional Mobile ManipulatorS (OMMS) with stability considerations. Numerical simulation results show that the presented methods successfully improve the stability level of the robot within an on-line planning process.(Received June 02 2008)(Online publication July 09 2008)
Journal of Intelligent and Robotic Systems, 2008
This work studies the dynamic modeling method for a service robot with Omni-directional Mobile Ma... more This work studies the dynamic modeling method for a service robot with Omni-directional Mobile ManipulatorS configuration. Based on screw theory, Lie group notations, reciprocal product of twist and wrench, and Jourdain principle, the robot’s motion equations including the whole body manipulation are formulated with left invariant representation. A legible and canonical dynamic model representing the relation between the inputs and the generalized dynamic load wrenches is presented. Considering the tradeoff between the symbolic concision, the modularization in code realization and the computation load, the dynamic model is decomposed into succinct block factorizations, and the basic computation unites are boiled down to the adjoint map corresponding to each joint. The traditional Lie bracket operation is extended to a generalized form. Computation efficiency, for the coefficient matrixes of the system motion equation, is discussed based on its special representation form. The generalization of the modeling method with Lie group and algebra tool is also summarized.
Consider a system of rigid bodies with multiple concurrent contacts. The multi-rigid-body contact... more Consider a system of rigid bodies with multiple concurrent contacts. The multi-rigid-body contact problem is to predict the accelerations of the bodies and the normal friction loads acting at the contacts. This paper presents theoretical results for the multi-rigid-body contact problem under the assumptions that one or more contacts occur over locally planar, finite regions and that friction forces are consistent with the maximum work inequality. Existence and uniqueness results are presented for this problem under mild assumptions on the system inputs. In addition, the performance of two different time-stepping methods for integrating the dynamics are compared on two simple multi-body systems.