| Manufacturing is the main body of the national economy.It is the mirror of the country's prosperity situation.With the accelerated deployment and implementation of the“China manufacturing 2025”plan,manufacturing industrial structure in our country has been transforming and industrial robots have been more and more widely used in handling,painting,welding and packaging automation production lines.In the field of transport robots,especially in high-load applications,the precision is usually not high enough because of the design defects of the control strategies and mechanical structures.In order to enrich the research of transport robots,improve accuracy of transporting task we add pneumatic power assist and balance strategy in the main load bearing joints taking into account the advantages of pneumatic system such as large force output,clean and easy to obtain,explosion-proof and fire prevention,while the AC servo motors are used to maintain a high position control accuracy.At the same time visual and Laser range sensor are used for a further improvment the installation accuracy and automation level.In this article,the work begins from the structural design of the pneumatic power assist experimental system.Combined with the project requirements,we complete the structural design and verification of transport robot which has six basic and three finetuning degrees of freedom and the selection of electric control system.At the same time,the linkage coordinate system of the experimental system is established,of which the kinematics and dynamic theoretical derivation are carried out and the rationality of the previous design is verified.Until now we have completed the design work in hardware level and made a foundation of follow-up simulation and experimental research.Design installation process for application of visual and Laser range sensor and ensure that the information obtained by those two kinds of sensors can be efficient and reasonable used in the workpiece position control by the end of the actuator.By researching on the related theory of machine vision field,this article determines the sensor model and configuration mode,simplfies the CCD image sensor imaging model and calibrates the visual system.We use the measurement information obtained by the machine vision sensor and the Laser range sensors to locate the end reference point,and then sums up the above process to the kinematic level to carry out theoretical derivation for the corresponding transformation matrix.This part of the work gives the power assist equipment initial access to the ability to perceive the outside worldMake a thorough study the working principle of equipment,and then construct the simulation model of the experimental equipment with the help of Matlab / Simulink and ADAMS software according to the mathematical model of key components and the Three-dimensional virtual model built in Pro/E software.Firstly,the kinematics and dynamic simulation of the experimental system are carried out by ADAMS motion model,three typical trajectories are abstracted according to the actual working conditions and then the law of the angle of each joint is obtained by trajectory planning to verify trace performance.After co-simulation,the practical performance of variable pressure gravity compensation controller and servo motor positioning control strategy is verified by the virtual prototype simulation based on the above trajectory planning results.Finally,the pneumatic power assist experimental platform is set up for debugging,and practical research is done to verify correctness of the previous theoretical research.This paper introduces the working principle of the experimental platform,and tests the tracking performance of the certain trajectory by the experimental results.The experimental results show that the pneumatic power assist transport robot experimental system designed above comes up to the requirements of project design. |
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