Unit 1: Robot Anatomy - Practice Quiz

1 What does the maximum position of a robot link represent?

2 What does the minimum position of a robot link represent?

3 What is a link in a robot?

4 What is a joint in a robot?

5 What does DOF stand for in robotics?

6 A robot with one independent rotary motion has how many degrees of freedom?

7 Which motion is produced by a revolute joint?

8 Which motion is produced by a prismatic joint?

9 What is a joint limit?

10 Why are maximum and minimum link positions determined in a laboratory experiment?

11 If a link moves between and , what is its angular range of motion?

12 If a prismatic link moves from cm to cm, what is its linear range?

13 What should be observed when visualizing the DOF of Sierena's Perro and Twist robot?

14 A joint that rotates about a fixed axis contributes which type of DOF?

15 A joint that slides along a straight guide contributes which type of DOF?

16 If two robot joints can move independently, how many DOF do they provide?

17 What is the usual first step when determining the position limits of a robot link?

18 At a joint's maximum limit, the connected link has reached its:

19 Why should a robot not be forced beyond its joint limits?

20 Which record is most useful when determining link positions?

21 A revolute link is allowed to rotate from to . What is its total available angular movement?

22 A prismatic link has a minimum position of mm and a maximum position of mm. What is its usable stroke length?

23 A planar two-link robot has link lengths mm and mm. When both links are fully extended in the same direction, what is the maximum distance of the end-effector from the base?

24 For the two-link robot with mm and mm, what is the minimum distance the end-effector can reach from the base?

25 A revolute joint in a robot is physically limited to the interval . Which pair represents its minimum and maximum positions?

26 During a laboratory test, a link reaches at its maximum position and at its minimum position. At what angular position is the midpoint of this range?

27 A robot link has a nominal range of to , but a mechanical stop reduces the positive limit to . What is the actual range of motion?

28 When visualizing DOF on a robot model, which observation best identifies a revolute degree of freedom?

29 A prismatic joint moves between mm and mm. If it is currently at mm, how much additional motion is available before reaching its maximum position?

30 A Twist robot is observed to have three independent joint variables: two angles and one linear displacement. What is its total number of DOF?

31 If changing one joint variable on Sierena's Perro moves only one connected link while the other joint values remain fixed, what does this demonstrate?

32 A link rotates from to . Which command sequence would best verify both positional limits in a robot visualization experiment?

33 A two-link planar mechanism has mm and mm. If the links are at to each other, what is the end-effector distance from the base?

34 A joint has limits of and . Which statement correctly describes its range and center position?

35 In a robot visualization, the end-effector position changes in the horizontal direction when one joint angle is varied. Which conclusion is most appropriate?

36 A robot link has a minimum angle of and a maximum angle of . A student records as a valid position. What is the correct assessment?

37 A robot is described by four joint coordinates, but one coordinate is always equal to the sum of two others. How many independent DOF does the robot have?

38 For a two-link arm with lengths mm and mm, which pair gives the theoretical minimum and maximum radial reach?

39 While testing Twist robot motion, changing one joint causes two links to move because the second link is attached to the first. How should the DOF be counted?

40 A link is tested at its minimum and maximum positions, but the end-effector does not move between the two tests. What is the most likely explanation?

41 A planar two-link serial arm has link lengths and . The first joint varies over , while the second joint varies over relative to link 1. What is the maximum reachable radial distance from the base?

42 For the same two-link arm with and , the joint limits permit a folded configuration with the links opposing each other. What is the minimum possible radial distance of the end effector from the base?

43 A revolute joint is mechanically limited to . A link attached to it has its maximum vertical coordinate at which joint position, assuming the link is measured from the joint axis?

44 A link of length rotates through . Its horizontal position is . At which endpoint is the minimum horizontal position obtained?

45 A robot leg is modeled as a planar two-link chain with and . If the knee angle is defined internally as for a fully folded configuration and for a straight configuration, which statement gives the correct radial limits?

46 A planar leg has joint coordinates and , where is relative to the first link. For and , what is the end-effector position?

47 A two-link planar manipulator is commanded to an extended configuration. Its Jacobian loses rank at this configuration. What is the most accurate interpretation for DOF visualization?

48 In a physical model of Sierena's Perro, one leg has three actuated revolute joints, but the foot is constrained to remain on a horizontal surface without slipping. How many independent instantaneous DOF remain for that leg under the contact constraint?

49 A Twist robot is modeled with a revolute base joint and a prismatic extension joint. The base angle is limited to , and the prismatic coordinate is limited to . Which workspace description is correct when the prismatic axis is radial?

50 During DOF visualization, a robot link appears stationary even though its joint angle changes. Which condition most plausibly explains this observation?

51 For a planar two-link robot, the end-effector position is and . Which condition identifies a positional singularity?

52 A three-link planar chain has lengths , , and . Without joint-limit restrictions, what is the minimum possible distance from the base to the end effector?

53 A three-link chain has lengths , , and . With unrestricted revolute joints, what is the minimum end-effector radius?

54 A four-joint robot leg has four actuated revolute joints, but the final two joints rotate about the same axis and always produce identical motion of the rigid distal link. What is the effective kinematic DOF of the leg?

55 A joint has an encoder range of to , but the physical link reaches its vertical maximum at . If the control software incorrectly treats as , what type of error is most likely during maximum-position determination?

56 For a two-link leg, and . The relative joint angle is restricted to . Which pair gives the radial maximum and minimum over this interval?

57 A Twist robot's end-effector position is recorded at four configurations. The measured coordinates vary in and , while orientation remains fixed. The actuator list contains two independent revolute joints. What is the most defensible DOF conclusion?

58 A leg on Sierena's Perro has hip, knee, and ankle joints. The hip and knee axes are parallel, while the ankle axis is perpendicular to them. Which visualization best distinguishes the joint DOF?

59 A two-link robot is tested at , where the links are fully extended. The measured end-effector speed is nearly zero even though both joint motors rotate slowly. Which explanation is correct?

60 A revolute link of length is attached to a rotating parent link. The child-link angle is defined relative to the parent. Which mistake produces an incorrect maximum-position plot?