Robotic and manufacturing automation, Mechanical Engineering

Consider the robotic manipulator of Fig. 1, with a Revolute and a Prismatic Joint. Figure 1, shows the side view of the manipulator while figure 2. shows the top view of the manipulator. The revolute (R) joint forms the shoulder of the manipulator and the prismatic (P) the elbow. The revolute joint provides a angular motion (back and forth) about the z0 in the base coordinate frame L0. The prismatic joint provides linear motion (up and down), enabling the end-effector (comprising a gripper tool) to approach close to ground level and to manipulate objects (e.g. performing a pick and place operation). When the gripper is at rest and before any action is performed, it is assumed that the end effector is at the same height with Link1. When an object is to be picked or placed on ground level the joint moves downwards. It is assumed that the tool tip can reach ground level. This implies that the length of Link2 is at least 450mm.

343_Robotic and Manufacturing Automation.png

The movement of the manipulator is performed in the following way. Assume that a square block has to be moved from position 1 to position 2 as shown in fig. 2.

1. Joint0 first moves up to the desired position θ

2. Joint1 then moves down to the height d of the pellet

3. The end effector then picks the block and Joint1 returns back to its initial position d=0

4. Joint0 then moves to the next position θ

Placing many objects with the manipulator in various positions, requires to perform the above basic movement for each object sequentially i.e. move the first object, then the second, then the third etc.
 We assume that:

1. The end effector picking task has a very small reaction time, so when the end effector is placed on the object it immediately grabs the object ± you don't have to consider, as soon as the object is reached, any delay due to gripper operation

2. The weights and inertia of the links are very small so all the force or torque generated by the drives of the joints is used for movement.

3. The angle when link1 is at rest is  =0, when link1 moves upwards is positive  >0 and when link1 moves downwards is negative θ< 0 .

Tasks:

A. Formulation:

1. Define the type of the manipulator's work envelope and its type

2. Define the manipulator configuration and choose appropriate joint drives (electric, pneumatic or hydraulic) and the relationship between the value of joint variables and actuation

Hint: In many cases prismatic joints employ linear drives that convert angular motion to linear displacement by means of a lead screw

3. Describe the models for each of the joint drives (transfer function or state-space model) ± input and outputs

4. Simulate each drive system in Matlab by applying a unit step response at each model

B. Control:

1. Design a control system for each of the drives of the joints. The combined movement of the two joints should place the gripper in the desired position.

2. Simulate the system response when applying the controller, by using the three reference signals.

Posted Date: 2/28/2013 7:05:26 AM | Location : United States







Related Discussions:- Robotic and manufacturing automation, Assignment Help, Ask Question on Robotic and manufacturing automation, Get Answer, Expert's Help, Robotic and manufacturing automation Discussions

Write discussion on Robotic and manufacturing automation
Your posts are moderated
Related Questions
Determine the stresses in the shell: A thin spherical shell of 1.5 m diameter & 8 mm thickness is filled having a liquid at an internal pressure of 1.5 N/mm 2 . Determine the

Product life-cycle management: There have also been changes in the use of some pre-existing data formats. Open associations have been formed to encourage some formats to becom

Determine the axial extension along a load: An open coiled helical spring is created having 10 turns of a mean radius of 60 mm. The wire diameter is 10 mm and coils make an an

(a) Calculate the natural frequency of mass m = 1 Kg placed at one end of a cantilever beam of negligible mass. Length of cantilever = 500 mm, d = 30 mm, b = 20 mm, E = 210x10 9 N


teori heat transfer conduction

Venturi Tube: A venturi is basically an air passage that has a shape similar to that shown in Figure that is narrower at the middle known as venturi tube. As air travels thro

nc & cnc machines

Basic Concep: Proper care and maintenance are essential for trouble free operation and optimum performance of the motorcycle. A quality service at regular intervals ensures that e

what is Direct and Reverse crank method of balancing