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types of robots.pptx

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Shashikanth Boorla
Shashikanth Boorla

This document discusses various methods of teaching and programming industrial robots. It describes four basic methods: 1) Walk-through teaching or pendant teaching, where the user guides the robot arm to positions using handheld controls and stores the joint positions. 2) Lead-through teaching, where the user physically moves a master arm to record a path that the robot then replays. 3) Offline programming, where a program is typed in with commands like "move axis A distance D". 4) Programming pick and place machines by setting mechanical end stops and programming the sequence of joint movements. The document provides details on each method and their implications.

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types of robots.pptx
types of robots.pptx
types of robots.pptx
types of robots.pptx
types of robots.pptx
Methods of teaching and programming How does an industrial robot determine what movement to make next? There are two extreme possibilities: the movement is calculated at the time, or it is replayed from an existing program or recording.
•The first method is necessary if the robot is to respond continuously to sensory inputs, e. g . if it is to follow a surface using a proximity sensor. An intermediate case is for the program to have branches selected by sensor signals, or to accept certain values, such as a desired gripper rotation angle, from an external source .
• Such a robot is always driven by a program, whether this is a sequence of indivisible actions, a sequence of target positions or a continuous record of position or velocity. • four basic methods of teaching and programming
PROGRAMMING PICK AND PLACE ROBOTS • The crudest form of programming is the setting up of a pick and place machine. • This has two parts: the mechanical end stops are set in place for each axis, and the sequence in which the joints operate is programmed. • The sequencer on early machines was a mechanical device such as a multi position rotary switch with several cams on its spindle, each cam operating contacts to switch power to the solenoid valves for the pneumatic cylinders.
PROGRAMMING PICK AND PLACE ROBOTS • controllers allow the storage of several programs, and these may have subroutines and allow a wide choice of time delays between actions. • One controller may be able to handle several robots in a coordinated way, and to interlock their operation with that of other machinery.
WALK-THROUGH TEACHING OR PENDANT TEACHING • This is the most usual method with point to point servo robots. A handheld box or 'pendant' has buttons, toggle switches or joysticks corresponding to each axis of the arm, which cause the axis to be driven under power. • The user drives the robot to a required position using these controls and then presses a button which causes all the joint position sensors to be read and their values stored
This method of teaching has certain consequences not obvious at first sight. An important one is that since the path between two programmed points is unspecified, and since there will usually be several joints active at once, the arm may not approach a target point from the same direction as it did during teaching. Therefore an extra point is often inserted into a program so that the approach to a critical point requires movement of just one axis. Intermediate points are also inserted to take the path round obstacles.
WALK-THROUGH TEACHING WITH PATH CONTROL • When the user has entered two points on the desired path, the robot's computer calculates a straight line between the points which the robot can follow, at a speed chosen by the user, at playback time. • An example of its uses is in paint spraying in cases where there are long straight runs of the spray gun, which can be specified by teaching just the start point and end point of the run.
LEAD-THROUGH TEACHING OR PHYSICAL ARM LEADING The user carries out the required motions with his own hand, while holding some device for recording the path taken. This device may be the manipulator itself or a replica arm, the 'master arm‘ or 'teaching arm', which is geometrically similar to the robot but is light enough to move easily, is unpowered and has angular or displacement sensors on its joints similar to those on the robot. The signals from these are recorded and become the program which the robot plays back. The program can be replayed at a fraction or multiple of the speed at which it was recorded.
OFF-LINE PROGRAMMING • The alternative to teaching a robot by driving it through its cycle of operations is to type in a program at a computer terminal. • In the simplest case the program consists of a series of commands of the form 'move axis A through distance D
THE IMPLICATIONS OF SENSING FOR ROBOT CONTROL
Analysis and Control • Analysis means finding a mathematical description of a robot in relation to its surroundings, which will allow the calculation of the geometric and dynamical quantities used in controlling it. • Control in the sense of this and the following sections means operating the robot's actuators so as to produce a specified path and velocity of the payload.
• It is nearly always assumed that a robot can be regarded as a chain of rigid links connected by revolute or prismatic joints at which actuators, regarded as torque or force generators, act. • With this assumption, there is a set of important problems in analysis and control…… They are….
• formulating the kinematic equations (joint coordinates to world coordinates) • solving the kinematic equations (world coordinates to joint coordinates); • the forward problem of dynamics - finding the motions resulting from joint torques; • the inverse problem of dynamics - finding the torques needed to produce a given motion; • specifying a trajectory between target points on the path; • actuator servo control - for a single actuator, how to drive it • so as to produce a specified position, velocity or torque.
FORMULATING THE KINEMATIC EQUATIONS • Kinematics is concerned with distances and angles and translational and angular velocities and accelerations, but not with forces, masses, torques and moments of inertia, which are the province of dynamics.
• A three dimensional coordinate system is embedded in each link, as shown in Figure 3.3. For each joint a transformation is found between the coordinate system of the two links it connects; if this operation is applied to each joint in succession, the relationship between any two links, including the payload and the fixed base of the robot, can be found. These transformations are expressed as equations called the kinematic equations of the manipulator
• It is convenient to use homogeneous coordinates for the system of each link, and in this case the kinematic equations take the form of matrix multiplications. Therein lies their advantage, for a chain of transformations is simply a chain of matrix multiplications and so the relationship between any two links is easily expressed.
SOLVING THE KINEMATIC EQUATIONS

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types of robots.pptx

  • 6. Methods of teaching and programming How does an industrial robot determine what movement to make next? There are two extreme possibilities: the movement is calculated at the time, or it is replayed from an existing program or recording.
  • 7. •The first method is necessary if the robot is to respond continuously to sensory inputs, e. g . if it is to follow a surface using a proximity sensor. An intermediate case is for the program to have branches selected by sensor signals, or to accept certain values, such as a desired gripper rotation angle, from an external source .
  • 8. • Such a robot is always driven by a program, whether this is a sequence of indivisible actions, a sequence of target positions or a continuous record of position or velocity. • four basic methods of teaching and programming
  • 9. PROGRAMMING PICK AND PLACE ROBOTS • The crudest form of programming is the setting up of a pick and place machine. • This has two parts: the mechanical end stops are set in place for each axis, and the sequence in which the joints operate is programmed. • The sequencer on early machines was a mechanical device such as a multi position rotary switch with several cams on its spindle, each cam operating contacts to switch power to the solenoid valves for the pneumatic cylinders.
  • 10. PROGRAMMING PICK AND PLACE ROBOTS • controllers allow the storage of several programs, and these may have subroutines and allow a wide choice of time delays between actions. • One controller may be able to handle several robots in a coordinated way, and to interlock their operation with that of other machinery.
  • 11. WALK-THROUGH TEACHING OR PENDANT TEACHING • This is the most usual method with point to point servo robots. A handheld box or 'pendant' has buttons, toggle switches or joysticks corresponding to each axis of the arm, which cause the axis to be driven under power. • The user drives the robot to a required position using these controls and then presses a button which causes all the joint position sensors to be read and their values stored
  • 12. This method of teaching has certain consequences not obvious at first sight. An important one is that since the path between two programmed points is unspecified, and since there will usually be several joints active at once, the arm may not approach a target point from the same direction as it did during teaching. Therefore an extra point is often inserted into a program so that the approach to a critical point requires movement of just one axis. Intermediate points are also inserted to take the path round obstacles.
  • 13. WALK-THROUGH TEACHING WITH PATH CONTROL • When the user has entered two points on the desired path, the robot's computer calculates a straight line between the points which the robot can follow, at a speed chosen by the user, at playback time. • An example of its uses is in paint spraying in cases where there are long straight runs of the spray gun, which can be specified by teaching just the start point and end point of the run.
  • 14. LEAD-THROUGH TEACHING OR PHYSICAL ARM LEADING The user carries out the required motions with his own hand, while holding some device for recording the path taken. This device may be the manipulator itself or a replica arm, the 'master arm‘ or 'teaching arm', which is geometrically similar to the robot but is light enough to move easily, is unpowered and has angular or displacement sensors on its joints similar to those on the robot. The signals from these are recorded and become the program which the robot plays back. The program can be replayed at a fraction or multiple of the speed at which it was recorded.
  • 15. OFF-LINE PROGRAMMING • The alternative to teaching a robot by driving it through its cycle of operations is to type in a program at a computer terminal. • In the simplest case the program consists of a series of commands of the form 'move axis A through distance D
  • 16. THE IMPLICATIONS OF SENSING FOR ROBOT CONTROL
  • 17. Analysis and Control • Analysis means finding a mathematical description of a robot in relation to its surroundings, which will allow the calculation of the geometric and dynamical quantities used in controlling it. • Control in the sense of this and the following sections means operating the robot's actuators so as to produce a specified path and velocity of the payload.
  • 18. • It is nearly always assumed that a robot can be regarded as a chain of rigid links connected by revolute or prismatic joints at which actuators, regarded as torque or force generators, act. • With this assumption, there is a set of important problems in analysis and control…… They are….
  • 19. • formulating the kinematic equations (joint coordinates to world coordinates) • solving the kinematic equations (world coordinates to joint coordinates); • the forward problem of dynamics - finding the motions resulting from joint torques; • the inverse problem of dynamics - finding the torques needed to produce a given motion; • specifying a trajectory between target points on the path; • actuator servo control - for a single actuator, how to drive it • so as to produce a specified position, velocity or torque.
  • 20. FORMULATING THE KINEMATIC EQUATIONS • Kinematics is concerned with distances and angles and translational and angular velocities and accelerations, but not with forces, masses, torques and moments of inertia, which are the province of dynamics.
  • 21. • A three dimensional coordinate system is embedded in each link, as shown in Figure 3.3. For each joint a transformation is found between the coordinate system of the two links it connects; if this operation is applied to each joint in succession, the relationship between any two links, including the payload and the fixed base of the robot, can be found. These transformations are expressed as equations called the kinematic equations of the manipulator
  • 22. • It is convenient to use homogeneous coordinates for the system of each link, and in this case the kinematic equations take the form of matrix multiplications. Therein lies their advantage, for a chain of transformations is simply a chain of matrix multiplications and so the relationship between any two links is easily expressed.