Unit 2: Specifications of Robot - Practice Quiz

1 What does robot accuracy describe?

2 What is meant by robot repeatability?

3 What does robot resolution indicate?

4 Which measurement is commonly used to describe a robot's position error?

5 In a U-BOT accuracy experiment, what is usually compared with the commanded position?

6 If a robot reaches a target at coordinates but stops at , what is the error along the -axis?

7 Why is a target position reached several times when estimating repeatability?

8 A robot that returns very close to the same point in repeated trials has good:

9 Which instrument or method can be used to record the position reached by U-BOT?

10 What is the purpose of recording several readings in a robot specification experiment?

11 Which value represents better repeatability?

12 What does payload mean in a robot specification?

13 What is the robot workspace?

14 Which specification describes how far the U-BOT end-effector can reach from its base?

15 A smaller positioning error generally means:

16 If the smallest commanded movement of U-BOT is mm, what is its approximate resolution?

17 Which factor can affect the measured accuracy of U-BOT?

18 What should be kept consistent during repeated U-BOT measurements?

19 Which robot specification is related to the time required to complete a movement?

20 Why should the U-BOT be operated within its specified payload?

21 The U-BOT is commanded to move its end effector to mm. The mean measured position after repeated trials is mm. What is the magnitude of the positioning error used to estimate accuracy?

22 During a U-BOT repeatability test, five measured points are , , , , and mm. What is the range of the measured -coordinates?

23 The U-BOT produces positions with a small average error but a large spread between trials. Which conclusion is most appropriate?

24 A U-BOT joint is commanded successively to positions separated by . The smallest commanded change that produces a measurable motion is . What is the practical resolution of this joint?

25 A U-BOT has a nominal positioning resolution of mm in the direction. Which command sequence is most suitable for experimentally checking this resolution?

26 For a commanded point mm, the U-BOT measurements are , , , and mm. What is the mean measured point?

27 The U-BOT is commanded to mm, but its mean measured position is mm. What is the direction of the mean positioning error?

28 A U-BOT reaches a target at mm with errors of , , , and mm. What is the maximum radial error?

29 The U-BOT repeats a point five times and the standard deviation of the radial position errors is mm. If repeatability is reported as approximately standard deviations, what value should be reported?

30 A U-BOT has an effective workspace of mm along the axis and mm along the axis. What is the rectangular workspace area?

31 The U-BOT completes a test path of length mm in s. What is its average linear speed during the test?

32 A U-BOT is rated for a maximum payload of kg. The end effector weighs kg and the workpiece weighs kg. What payload margin remains?

33 A U-BOT's positioning errors at one target are mm and at another target are mm. What does this pattern mainly suggest?

34 The U-BOT's measured endpoint spread increases when the arm is fully extended. Which specification is most directly affected by this observation?

35 A U-BOT has a maximum joint speed of /s. Approximately how long does a joint movement take if the joint moves at its rated speed?

36 The U-BOT is commanded to move from mm to mm. Due to calibration error, it reaches mm. What is the magnitude of the final position error?

37 When estimating U-BOT accuracy, why should the commanded target be approached from the same direction in every trial?

38 Two U-BOT configurations have the following results: Configuration A has mean error mm and spread mm; Configuration B has mean error mm and spread mm. Which statement is correct?

39 A U-BOT position command uses coordinates rounded to the nearest millimeter. What is the maximum rounding uncertainty in one coordinate, assuming rounding is unbiased?

40 A U-BOT has a positional resolution of mm per axis. If independent resolution limits occur in both and , what is the corresponding diagonal quantization distance?

41 During a U-BOT positioning test, the commanded point is and the mean measured point is . What is the Euclidean positioning accuracy error of the mean position?

42 A U-BOT reaches a target ten times. The measured radial errors from the target are . Which interpretation is most defensible?

43 At one U-BOT target, repeated endpoint coordinates have standard deviations , , and . Assuming independent axes, what is the three-dimensional standard deviation of the endpoint cloud?

44 The U-BOT controller accepts commanded increments of , but encoder quantization corresponds to at the tool tip. Which value best represents the practical translational resolution of the complete system?

45 A U-BOT has a repeatability specification of and an accuracy specification of . A calibration removes a constant bias without changing random scatter. What performance should be expected after calibration?

46 For a U-BOT, the reachable workspace is specified as a radial annulus from to . A target is located from the base axis. What is the correct conclusion?

47 The U-BOT can move at a maximum joint speed of . For a joint that must rotate through , ignoring acceleration and deceleration, what is the theoretical minimum motion time?

48 A U-BOT carries a payload at a horizontal reach of . If the allowable static wrist torque is , what additional payload mass can be carried at the same reach, neglecting gripper mass?

49 A U-BOT's endpoint positions form a circular cloud with a measured diameter of when repeatability is reported as a radius containing all observations. What repeatability value should be reported under that convention?

50 The U-BOT is tested at three targets. Mean absolute position errors are , , and , while the corresponding repeatability radii are , , and . Which statement is correct?

51 A U-BOT moves a tool through a straight-line path of length at a programmed speed of . The controller adds a fixed dwell of at each endpoint and executes 12 complete point-to-point cycles. What is the total ideal cycle-test time?

52 The U-BOT tool position is commanded to increase by per trial. The observed positions remain unchanged for the first two increments and then jump by . Which specification is most directly revealed by this behavior?

53 For a planar two-link U-BOT configuration, the Jacobian determinant approaches zero as the links become collinear. Which specification is most likely to degrade near this configuration?

54 A U-BOT has a static repeatability radius of , but its endpoint temperature drift is . During a test, temperature changes by . If drift is uncorrected and aligned with the worst-case repeatability direction, what maximum radial deviation should be expected?

55 A U-BOT's data sheet lists a maximum payload of at a reach. Assuming the allowable joint torque is fixed, what payload is theoretically allowed at a reach, ignoring the arm's own weight?

56 Repeated U-BOT measurements at a target have mean coordinates instead of the commanded . The standard deviations are below on every axis. Which diagnosis is best supported?

57 A U-BOT's measured endpoint errors are , , , and along one axis. If a calibration offset of is applied, what is the principal expected effect?

58 Two U-BOT configurations produce the following results: Configuration A has mean error and repeatability radius ; Configuration B has mean error and repeatability radius . Which configuration is preferable for an application requiring consistent placement after calibration?

59 A U-BOT specification states a positional resolution of and repeatability of . A student concludes that every commanded change will be realized within . What is the flaw?

60 For a U-BOT, the workspace test records an range of and a range of . A rectangular approximation is used only for volume estimation with a fixed vertical range of . What is the estimated workspace volume?