scara机器人.pptx

Design,construction and control of a SCARA manipulator with 6 degrees of freedom,01,02,04,Introduction,General design,State of the art,Abstract,CONTENTS,03,05,06,07,Control software,Tests and results,Conclusions,Abstract,PART 01,The design and implementation of a robot manipulator with 6 degrees of freedom(DOF),which constitutes a physical platform on which a variety of control techniques can be tested and studied,are presented.The robot has mechanical,electronic and control systems,and the intuitive graphic interface designed and implemented for it allows the user to easily command this robot and to generate trajectories for it.,Introduction,Over the past few decades,robotics has played a very important part in process automation,with robot manipulators assuming a leading role in the development of several productive areas.Nowadays,industrial robots are used for the automation of a variety of tasks such as assembling,transfer of materials,all kinds of welding,precision cutting of materials,palletizing,painting,among many possible applications.,PART 02,The present work arises from the compelling need of having real platforms to carry out scientic research and its corresponding validations.Therefore,this paper presents the process of design and construction of a robot with a SCARA conguration,which has great application in the present day industry.,State of the art,PART 03,Industrial robots,Robot control,Industrial robots,There are various types of robots,which depending on their physical conguration can be classied into many-jointed,mobile,zoomorphic,android,and hybrid.In the many-jointed category we have industrial robots like the one shown in Figure 1.An industrial robot can be considered as a set of integrated subsystems that correspond to a manipulator or mechanical arm,a terminal effector,motor elements or actuators,information sensors,and controllers.Many people are working on perfecting the industrial robot to make it better service in produce.,Robot control,Robot control has the purpose of sending control signals to the joints to make a robot follow a specied trajectory.A number of control algorithms with different characteristics and complexities have been developed.In this paper,the Decoupled Control was adopted,because the aim is to validate the correct functioning of this newly designed and implemented robot.This control technique is quite simple to implement,since it does not take into account perturbations generated between the robots joints,i.e.,each joint is controlled in an independent way commonly by means of one PID controller per joint.The PID controller intrinsically attempts to correct perturbations that produce errors,which must be canceled out.The following equation describes the PID controller:,PART 04,General design,Complete system,Robot,Electronic design and interface,Complete system,A SCARA manipulator,communicated with a PC-Controller that uses the Matlab/Simulink software,is designed and built.Since the robot and the PC-Controller must interact with each other,an electronic interface capable of performing the task is also developed,thereby constituting a link between both parts.The systems general diagram in Figure 2 shows the components of the system.,Robot,Originally,this robot had an RRP conguration plus a terminal effector,to which two joints and a clamp have been added,with a resultant RRPRRP conguration that was selected because of its representativeness in the current industry.Figure 3 shows the design and dimensions of the robot.,Figure 4 shows the working range of four sensors used in the robot manipulator:two rotational encoder sensors(SR-1 and SR-2),a linear encoder sensor(SP-3),and a FlexiForce force sensor(SF-4).,Because of the working range of the four sensors the robots work space is basically cylindrical.But in a particular case it resembles a cardioid quite closely(Fig.5),Electronic design and interface,The electronic interface is the link between the robot and the PC-Controller,as seen in Figure 6.It has the purpose of providing the drivers needed to convert the numerical data from the PC-Controller into signals for the actuators and to convert the signals coming from the sensors of the robot into numbers to be sent to the PC-Controller.The information is sent through a serial port using the RS-232 protocol.,PART 05,Control software,The robot has 6 actuators,control systems for actuators M-1,M-2 and M-3 are designed and implemented in the PC-Controller,and they are fed back in position by means of encoders SR-1,SR-2 and SP-3,respectively.Such systems are independent for each actuator,although all the blocks of the application are contained in a single Simulink model that is operated from the systems GUI4 application,where the trajectories are programmed and previsualized.This Simulink model includes the following blocks:1.Communication.2.Controllers.3.Trajectory containers.4.Graphic visualizers of results.,PART 06,Tests and results,The tests conducted with the robot consisted in the application of steps and trajectories to the joints at different speeds,R-1,R-2 and P-3 independently feedback control,and nally a test comprising a programmed task in which simultaneous functioning of all the joints is involved.,R-1 rotational joint,For R-1 joint,in both directions,Figure 12 shows in green the application of a 60 step and in blue the performance of the robot.This kind of signal is the one that generates the most abrupt response of the link,because at the beginning of the movement the position error is very large,so the controller makes the actuator move at high speeds that depend on the amplitude of that step.Figure 13 presents,for R-1 joint,in both directions,the application of a cubic polynomial curve at a speed of 60/s and the performance of the robot in green and blue,respectively.,R-2 rotational joint,The same stepwise tests(Fig.15)and the curves at speeds set at 75/s(Fig.16)is applied to R-2 joint.,P-3 prismatic joint,These two picture are the test result of P-3 prismatic joint.Fig.18 shows the response of P-3 joint to steps between 50 and 100 mm.Fig.19 shows the response of the P-3 joint to cubic polynomial curves at 25 mm/s.,PART 05,Conclusions,A SCARA manipulator with 6 DOF was designed and implemented,and it now constitutes a physical platform on which a variety of control techniques can be tested and studied.The development of the PC-Controllers software,which is the same as the electronic interface,despite the complexity of its design and implementation,allowed an optimum functioning of the complete system.This software,among other functions,also enables the generation of multiple trajectories for the robot.,Thanks for watching!,