代写EE6221 - ROBOTICS AND INTELLIGENT SENSORS SEMESTER 2 EXAMINATION 2022-2023代做Processing

日期：2025-02-14 12:37

EE6221-ROBOTICS AND INTELLIGENT SENSORS

SEMESTER 2 EXAMINATION 2022-2023

1. A robotic manipulator with seven joints is shown in Figure 1.

Figure 1

(a) Obtain the link coordinate diagram by using the Denavit-Hartenberg (D-H) algorithm. (12 Marks)

(b)।Derive the kinematic parameters of the robot based on the coordinate diagramobtained in part (a). (8 Marks)

2.The dynamic equations of a robot, which is in contact with a frictionless surface, are given as follows:

where qi, q2, q3 are the joint variables, u1, u2, u3 are the control inputs and g = 9.8 m/s2 is the acceleration due to gravity. The first two joints possess unmodelled resonance at 12 rad/sec and the third joint possesses unmodelled resonance at 16 rad/sec. The contact force exerted on the environment is given by:

f = 10(q3 - 0.1).

(a) Design a hybrid position and force controller for the robot so that the first two joints are critically damped, and the third joint is overdamped with a damping ratio of 1.2. The gains should be as large as possible, and the system should not excite all the unmodelled resonances.(14 Marks)

(b) The controller designed in part (a) is now implemented on the robot in a space station, without any modification. Explain the possible effects and derive the error equations.(6 Marks)

3. (a) A mobile robot with two castor wheels, one standard wheel and one steered standardwheel, is shown in Figure 2 on page 3. A local reference frame. (xr, yr) and a steered angle ß are assigned to the mobile robot as shown in Figure 2. The radius of each standard wheel is 7cm and the radius of each castor wheel is 3cm. If the rotational velocities of the steered standard wheel, standard wheel and the two castor wheelsare denoted by φss, s,c1 and φc2, respectively, derive the rolling and slidingconstraints of the mobile robot. (10 Marks)

Figure 2

(b) A robot manipulator with three joint variables q1, 92, 93 are mounted on a mobile robot. The link-coordinate homogeneous transformation matrix from the base coordinate to the tool coordinate of the robotic manipulator is given as:

where S1 = sin (q1), S2 = sin(q2), C1 = cos (q1), C2 = cos (q2).

(i) Solve the inverse kinematic problem using an analytic method to express (q1, q2, q3)T in terms of the position of the end effector (x, y, z)T. (Note: orientation is not required).

(ii) If the robot is used to pick up an object with a centroid given as x= 0.15, y=0.25, z=0.025 units, calculate the joint configuration. Discuss the problems associated with this task. (10 Marks)