Heavy-load transfer robots are widely used in automobile production and machinery manufacturing to improve production efficiency.In order to meet the needs of large billet transfer,a 4-DOF transfer robot is designed i...Heavy-load transfer robots are widely used in automobile production and machinery manufacturing to improve production efficiency.In order to meet the needs of large billet transfer,a 4-DOF transfer robot is designed in this paper,which consists of parallel four-bar mechanisms.The Jacobian matrix referring to the mapping matrix from the joint velocity to the operating space velocity of the transfer robot can be solved by the differential-vector method.The mean value of the Jacobian matrix condition number in the workspace is used as the global performance index of the robot velocity and the optimization goal.The constraint condition is established based on the actual working condition.Then the linkage length optimization is carried out to decrease the length of the linkage and to increase the global performance index of velocity.The total length of robot rods is reduced by 6.12%.The global performance index of velocity is improved by 45.15%.Taking the optimized rod length as the mechanism parameter,the distribution of the motion space of the transfer robot is obtained.Finally,the results show that the proposed method for establishing the Jacobian matrix of the lower-mobility robot and for the optimization of the rods based on the velocity global performance index is accurate and effective.The workspace distribution of the robot meets the design requirements.展开更多
The transfer matrix of wrist force sensor is important for decoupling theoutput signals and enhancing the precision of wrist force sensor.This paper solves thetransfer matrix from the realization of optimal approximat...The transfer matrix of wrist force sensor is important for decoupling theoutput signals and enhancing the precision of wrist force sensor.This paper solves thetransfer matrix from the realization of optimal approximation of polynomial.First,thegeneral transfer matrix algorithm in the sense of L^2 and two kinds of modified algorithmare proposed.Then,starting from uniform approximation,the optimal transfer matrixalgorithm is offered and solved by the use of linear programming.The results of experi-ment and computation prove that these algorithms are effective.展开更多
Due to the increasing commercial interest in autonomy and sustainability,this paper reviews and presents a comprehensive summary of the resonant-inductive power transmission(RPT)technology for autonomous mobile robots...Due to the increasing commercial interest in autonomy and sustainability,this paper reviews and presents a comprehensive summary of the resonant-inductive power transmission(RPT)technology for autonomous mobile robots.It outlines historic and recent research activities in wireless power transmission,covering the fundamental operation of microwave,capacitive and inductive power transfer technologies,state-of-the-art developments in RPT for high-power applications,current design and health standards,technological drawbacks,and possible future trends.In this paper,coupling-enhanced pad designs,adaptive tuning techniques,compensation network designs,and control techniques are explored.Major design issues such as coupling variation,frequency splitting,and bifurcation are reviewed.The difference between maximum power transfer and maximum energy efficiency is highlighted.Human exposure guidelines are summarized from documentations provided by the Institute of Electrical and Electronics Engineers(IEEE)and the International Commission on Non-ionizing Radiation Protection(ICNIRP).Other standards like WPC’s Qi and Airfuel design standards are also summarized.Finally,the possible trends of the relevant research and development,particularly dynamic charging,are discussed.The intention of this review is to encourage designs that will relieve robot operators of the burden of frequent manual recharging,and to reduce downtime and increase the productivity of autonomous mobile robots in industrial environments.展开更多
The previous research regarding the gait planning of quadruped robot focuses on the sequence for lifting o and placing the feet, but neglects the influence of body height. However, body height a ects gait performance ...The previous research regarding the gait planning of quadruped robot focuses on the sequence for lifting o and placing the feet, but neglects the influence of body height. However, body height a ects gait performance significantly, such as in terms of the stride length and stability margin. We herein study the performance of a quadruped robot using the equivalent mechanism concept based on metamorphosis. Assuming the constraints between standing feet and the ground with hinges, the ground, standing legs and robot body are considered as a parallel mechanism, and each swing leg is regarded as a typical serial manipulator. The equivalent mechanism varies while the robot moves on the ground. One gait cycle is divided into several periods, including step forward stages and switching stages. There exists a specific equivalent mechanism corresponding to each gait period. The robot's locomotion can be regarded as the motion of these series of equivalent mechanisms. The kinematics model and simplified model of the equivalent mechanism is established. A new definition of the multilegged robot stability margin, based on friction coe cient, is presented to evaluate the robot stability. The stable workspaces of the equivalent mechanism in the step forward stage of trotting gait under di erent friction coe cients are analyzed. The stride length of the robots is presented by analyzing the relationship between the stable workspaces of the equivalent mechanisms of two adjacent step forward stages in one gait cycle. The simulation results show that the stride length is larger with increasing friction coe cient. We herein propose a new method based on metamorphosis, and an equivalent mechanism to analyze the stability margin and stable workspace of the multilegged robot.展开更多
Curved coils constructed by flexible printed circuit board (PCB) or hand-wound Litz-wire have been steadily becoming popular due to its applicable potential on devices that have a curved body. Inductive Power Transfer...Curved coils constructed by flexible printed circuit board (PCB) or hand-wound Litz-wire have been steadily becoming popular due to its applicable potential on devices that have a curved body. Inductive Power Transfer (IPT) systems based on curved coils and flexible ferrite sheets may provide more flexible charging solutions for various electronic devices such as rice cookers and robot vacuum cleaners. Power repeaters are also used in IPT systems to extend wireless charging range by guiding magnetic fields to the receiving coil. The interaction of these three topics could be inspiring. In this paper, two adjustable power repeaters are applied to an IPT charging system with various curved receiving coils designed for vacuum cleaners. Two power repeaters share the identical structure as the Tx coil and could be rotated to mirror symmetrically. The input and output power are calculated by analyzing the equivalent circuit model. The self-inductance, mutual inductance, and coupling coefficient of the proposed system are obtained via finite element method simulation with variable rotating angles. Three typical IPT designs have also been simulated in ANSYS Maxwell and compared with the proposed magnetic design. The comparison indicates the enhancing feature of the passive power repeaters on coupling performance and the ability to guide the magnetic flux for better magnetic field coupling. Furthermore, two types of co-simulations defined by the power source via Simplorer are conducted to explore how much power could be transferred. The tuned system is shown to be able to provide about 32 W under 100 kHz operating frequency for charging the battery of a robot vacuum cleaner. The results from theoretical calculation and simulation align well with each other.展开更多
The precise control upon each degree of freedom of a robotic arm is a great challenge in implementing industrial work. This paper aims to design a novel controller for an automated robotic arm. A discrete Proportional...The precise control upon each degree of freedom of a robotic arm is a great challenge in implementing industrial work. This paper aims to design a novel controller for an automated robotic arm. A discrete Proportional Integral Derivative (PID) control technique is being used to replace the complex electronic circuitry, which would greatly reduce the cost and size of the controller. DC motors will be controlled on the basis of Closed-loop System using an avr (Atmega 16/32) microcontroller. Transfer functions have been derived for mathematical modeling of the system through which the stability of the system can be evaluated prior to fabrication.展开更多
基金supported by the National Key R&D Program of China(No.2018YFB1307900)the Natural Science Foundation of Shanxi Province(Nos.201901D211009,201901D211010)the Technology In⁃novation Foundation of Shanxi University(No.2019L 0177).
文摘Heavy-load transfer robots are widely used in automobile production and machinery manufacturing to improve production efficiency.In order to meet the needs of large billet transfer,a 4-DOF transfer robot is designed in this paper,which consists of parallel four-bar mechanisms.The Jacobian matrix referring to the mapping matrix from the joint velocity to the operating space velocity of the transfer robot can be solved by the differential-vector method.The mean value of the Jacobian matrix condition number in the workspace is used as the global performance index of the robot velocity and the optimization goal.The constraint condition is established based on the actual working condition.Then the linkage length optimization is carried out to decrease the length of the linkage and to increase the global performance index of velocity.The total length of robot rods is reduced by 6.12%.The global performance index of velocity is improved by 45.15%.Taking the optimized rod length as the mechanism parameter,the distribution of the motion space of the transfer robot is obtained.Finally,the results show that the proposed method for establishing the Jacobian matrix of the lower-mobility robot and for the optimization of the rods based on the velocity global performance index is accurate and effective.The workspace distribution of the robot meets the design requirements.
文摘The transfer matrix of wrist force sensor is important for decoupling theoutput signals and enhancing the precision of wrist force sensor.This paper solves thetransfer matrix from the realization of optimal approximation of polynomial.First,thegeneral transfer matrix algorithm in the sense of L^2 and two kinds of modified algorithmare proposed.Then,starting from uniform approximation,the optimal transfer matrixalgorithm is offered and solved by the use of linear programming.The results of experi-ment and computation prove that these algorithms are effective.
基金partially funded by the Natural Sciences and Engineering Research Council of Canada(NSERC)through the Discovery Grant Program(RGPIN2018-05471 and RGPIN-2017-05762).
文摘Due to the increasing commercial interest in autonomy and sustainability,this paper reviews and presents a comprehensive summary of the resonant-inductive power transmission(RPT)technology for autonomous mobile robots.It outlines historic and recent research activities in wireless power transmission,covering the fundamental operation of microwave,capacitive and inductive power transfer technologies,state-of-the-art developments in RPT for high-power applications,current design and health standards,technological drawbacks,and possible future trends.In this paper,coupling-enhanced pad designs,adaptive tuning techniques,compensation network designs,and control techniques are explored.Major design issues such as coupling variation,frequency splitting,and bifurcation are reviewed.The difference between maximum power transfer and maximum energy efficiency is highlighted.Human exposure guidelines are summarized from documentations provided by the Institute of Electrical and Electronics Engineers(IEEE)and the International Commission on Non-ionizing Radiation Protection(ICNIRP).Other standards like WPC’s Qi and Airfuel design standards are also summarized.Finally,the possible trends of the relevant research and development,particularly dynamic charging,are discussed.The intention of this review is to encourage designs that will relieve robot operators of the burden of frequent manual recharging,and to reduce downtime and increase the productivity of autonomous mobile robots in industrial environments.
基金Supported by National Natural Science Foundation of China(Grant Nos.51775011,91748201)
文摘The previous research regarding the gait planning of quadruped robot focuses on the sequence for lifting o and placing the feet, but neglects the influence of body height. However, body height a ects gait performance significantly, such as in terms of the stride length and stability margin. We herein study the performance of a quadruped robot using the equivalent mechanism concept based on metamorphosis. Assuming the constraints between standing feet and the ground with hinges, the ground, standing legs and robot body are considered as a parallel mechanism, and each swing leg is regarded as a typical serial manipulator. The equivalent mechanism varies while the robot moves on the ground. One gait cycle is divided into several periods, including step forward stages and switching stages. There exists a specific equivalent mechanism corresponding to each gait period. The robot's locomotion can be regarded as the motion of these series of equivalent mechanisms. The kinematics model and simplified model of the equivalent mechanism is established. A new definition of the multilegged robot stability margin, based on friction coe cient, is presented to evaluate the robot stability. The stable workspaces of the equivalent mechanism in the step forward stage of trotting gait under di erent friction coe cients are analyzed. The stride length of the robots is presented by analyzing the relationship between the stable workspaces of the equivalent mechanisms of two adjacent step forward stages in one gait cycle. The simulation results show that the stride length is larger with increasing friction coe cient. We herein propose a new method based on metamorphosis, and an equivalent mechanism to analyze the stability margin and stable workspace of the multilegged robot.
文摘Curved coils constructed by flexible printed circuit board (PCB) or hand-wound Litz-wire have been steadily becoming popular due to its applicable potential on devices that have a curved body. Inductive Power Transfer (IPT) systems based on curved coils and flexible ferrite sheets may provide more flexible charging solutions for various electronic devices such as rice cookers and robot vacuum cleaners. Power repeaters are also used in IPT systems to extend wireless charging range by guiding magnetic fields to the receiving coil. The interaction of these three topics could be inspiring. In this paper, two adjustable power repeaters are applied to an IPT charging system with various curved receiving coils designed for vacuum cleaners. Two power repeaters share the identical structure as the Tx coil and could be rotated to mirror symmetrically. The input and output power are calculated by analyzing the equivalent circuit model. The self-inductance, mutual inductance, and coupling coefficient of the proposed system are obtained via finite element method simulation with variable rotating angles. Three typical IPT designs have also been simulated in ANSYS Maxwell and compared with the proposed magnetic design. The comparison indicates the enhancing feature of the passive power repeaters on coupling performance and the ability to guide the magnetic flux for better magnetic field coupling. Furthermore, two types of co-simulations defined by the power source via Simplorer are conducted to explore how much power could be transferred. The tuned system is shown to be able to provide about 32 W under 100 kHz operating frequency for charging the battery of a robot vacuum cleaner. The results from theoretical calculation and simulation align well with each other.
文摘The precise control upon each degree of freedom of a robotic arm is a great challenge in implementing industrial work. This paper aims to design a novel controller for an automated robotic arm. A discrete Proportional Integral Derivative (PID) control technique is being used to replace the complex electronic circuitry, which would greatly reduce the cost and size of the controller. DC motors will be controlled on the basis of Closed-loop System using an avr (Atmega 16/32) microcontroller. Transfer functions have been derived for mathematical modeling of the system through which the stability of the system can be evaluated prior to fabrication.
