Unit 3: Robot Coordinate System - Practice Quiz

1 What does the world coordinate system represent when working with NINO V2?

2 Which coordinate system normally moves along with the gripper of NINO V2?

3 What information is described by the position of the gripper?

4 What information is described by the orientation of the gripper?

5 Which three values commonly represent a position in Cartesian coordinates?

6 Which set of angles is commonly used to describe gripper orientation?

7 What is the usual size of a homogeneous transformation matrix in three-dimensional robotics?

8 Which part of a homogeneous transformation matrix represents orientation?

9 Which part of a homogeneous transformation matrix represents position?

10 What does an identity transformation indicate?

11 What is the purpose of the inverse of a transformation from the gripper frame to the world frame?

12 If the gripper moves along its own -axis, which reference frame defines that motion?

13 If NINO V2's gripper rotates without changing its location, which quantity changes?

14 If the gripper translates without rotating, which quantity remains unchanged?

15 Why are coordinate transformations used in a NINO V2 laboratory exercise?

16 Which action is appropriate when verifying the calculated gripper position?

17 Before comparing two gripper positions, what should be confirmed?

18 In a standard right-handed coordinate system, which axes are normally used?

19 What should be checked when verifying the orientation of NINO V2's gripper?

20 What does the origin of the gripper coordinate system identify?

21 In NINO V2, a point has world coordinates m. If the gripper frame origin is at m and both frames have the same orientation, what are the point coordinates relative to the gripper frame?

22 A gripper frame in NINO V2 is rotated counterclockwise about the world -axis. A point has gripper coordinates m, and the gripper origin is at the world origin. What are its world coordinates?

23 Which homogeneous transformation matrix correctly represents a gripper translated by m and having no rotation relative to the NINO V2 world frame?

24 The measured gripper pose in the world frame is . To express a world-frame point using gripper coordinates during verification, which operation should be used?

25 A gripper orientation is represented by . Which condition best verifies that the measured orientation matrix is a valid rigid-body rotation matrix?

26 The gripper origin is measured at m in the world frame. A target point is m, and the gripper axes are aligned with the world axes. What displacement should be observed in the gripper frame?

27 During a NINO V2 experiment, the gripper is rotated about the world -axis without translating. A point located m along the gripper -axis will appear where in world coordinates relative to the gripper origin?

28 If the transformation from gripper to world is and the transformation from world to gripper is , what relationship should hold in an ideal verification?

29 A point has gripper coordinates . The measured transform is with m. What world position should be verified?

30 When the gripper frame is rotated relative to the world frame, why must the rotation matrix be applied before adding the gripper origin translation?

31 The world-frame position of the NINO V2 gripper is measured as m, while the expected calibration value is m. What is the position error vector measured minus expected?

32 A world-frame point is m. The gripper origin is m, and its -axis points opposite to the world -axis while its and axes are aligned. What are the gripper coordinates of the point?

33 Which test most directly verifies both position and orientation of the NINO V2 gripper with respect to the world frame?

34 The gripper pose changes while the grasped object remains fixed in the world. Which quantity should remain approximately constant when the object is transformed into world coordinates?

35 A gripper-frame vector is . The gripper is rotated about the world -axis. What is the corresponding world-frame vector?

36 For a homogeneous transform , which part specifies the position of the gripper origin in the world frame?

37 A measured orientation matrix has orthogonal columns but determinant . What does this indicate during NINO V2 transformation verification?

38 If the gripper origin is correct but every transformed point has an error that increases with its distance from the origin, which component is most likely incorrect?

39 A target is at world coordinates m. The gripper origin is m, and the gripper is aligned with the world frame. Along which gripper direction should the gripper move to reach the target?

40 Two independently computed transforms for the same NINO V2 gripper pose differ by a small translation but have identical rotation matrices. Which verification result is directly affected?

41 A point measured in the gripper frame is . The gripper pose in the world frame is . What is the point's world-frame position?

42 The gripper orientation relative to the world is a rotation about world . A tool vector is . Which world-frame vector should be observed if the transform convention is ?

43 A measured homogeneous matrix has a rotation block whose columns are nearly orthogonal, but its determinant is . What is the most appropriate conclusion during NINO V2 transformation verification?

44 The forward transform from gripper to world is . Which operation correctly converts a point recorded in the world frame into gripper coordinates?

45 A world-frame target is . The gripper origin is , and its axis points along world . What gripper-frame coordinates should the target have?

46 Two independently measured rigid transforms are and . Which residual is most suitable for checking their relative position and orientation rather than subtracting all 16 matrix entries?

47 A gripper-frame point is transformed using , but the reported world position is consistently displaced by the same vector for every test point. Which fault is most likely?

48 A rotation matrix is reconstructed from noisy axis measurements. Which validation set is sufficient to determine whether it represents a proper rigid-body orientation?

49 The NINO V2 controller uses column vectors and applies transforms from right to left. A world pose is defined by first rotating the gripper frame by and then translating it by . Which homogeneous form is correct?

50 A tool marker is stationary in the world, but its gripper-frame coordinates change as the gripper rotates. What should remain invariant during verification?

51 A pose estimate reports Euler angles near a pitch of , and small roll and yaw changes produce large reported angle variations. Which interpretation is most accurate?

52 For a rigid transform , two points have gripper-frame separation . What relation must hold in the world frame?

53 A calibration test gives position residuals of mm and an orientation residual of . The acceptance limits are mm per axis and . What is the correct verdict?

54 A measured gripper pose has translation and rotation . A fixed tool-center-point offset is . Which expression gives the tool-center-point position in the world frame?

55 The world-frame transform is known, but a software test incorrectly uses while retaining the original translation . Which result is generally expected?

56 The same physical marker is used to verify both position and orientation. Which measurement arrangement provides the strongest orientation verification?

57 A transform is reported as , but the test script applies it to world-frame points and obtains plausible-looking results. Which diagnostic best exposes a frame-label reversal?

58 During repeated NINO V2 measurements, position residuals have near-zero mean but grow with the distance of the test point from the gripper origin. Orientation residuals also grow slightly. What issue is most consistent with this pattern?

59 Suppose the world frame is changed by a known transform . How should the gripper pose be expressed in the new world frame?

60 A controller uses millimeters for translation, while the verification script assumes meters. Which symptom most directly identifies this mismatch?