Unit 1: Measurements in Robotics - Practice Quiz

1 What is the main function of a sensor in a robotic system?

2 What does a transducer do?

3 Which device is commonly used to detect the temperature of a robot motor?

4 What is measurement error?

5 Which type of error causes repeated measurements to be consistently too high or too low?

6 Random errors in sensor measurements usually cause readings to:

7 In robotics, what is an internal sensor mainly used to measure?

8 Which sensor is commonly used to measure the angular position of a robot joint?

9 What distinguishes a smart sensor from a basic sensor?

10 Which component of a smart sensor converts an analog signal into digital data?

11 Which smart-sensor component performs calculations on measured data?

12 What is the purpose of sensor calibration?

13 During calibration, a sensor reading is normally compared with:

14 What does zero-point calibration correct?

15 Which sensor characteristic describes how close a measured value is to the true value?

16 What is sensor sensitivity?

17 What does sensor resolution describe?

18 Why is an amplifier used in sensor signal conditioning?

19 What is noise in a sensor signal?

20 Which filter is commonly used to reduce high-frequency noise while retaining slow signal changes?

21 A robotic arm uses a device that converts joint angle into an electrical voltage. Which description best identifies this device?

22 A force sensor produces a change in resistance when pressure is applied. In this arrangement, the change in resistance is best described as:

23 A distance sensor gives readings of 99, 100, 101, and 100 cm when the actual distance is 105 cm. Which statement is most accurate?

24 A temperature sensor has an output error that increases by for every increase in input. This error is most closely classified as:

25 Which sensor classification is most appropriate for a camera that measures reflected light without physically contacting the object?

26 A mobile robot must detect obstacles at different distances while moving quickly. Which sensor property is most important for reducing delayed reactions?

27 Two sensors are used to measure the same variable. Sensor A consumes no external power, while Sensor B requires an excitation voltage. How are they generally classified?

28 A robot uses several sensors whose outputs are sampled by one controller. What is the main advantage of sensor fusion in this situation?

29 Which component allows a smart sensor to compensate for a known nonlinear response before sending data to the robot controller?

30 A smart accelerometer contains a sensing element, an ADC, a processor, and a communication interface. What is the primary role of the ADC?

31 Why can local processing in a smart sensor reduce communication requirements in a robotic system?

32 A pressure sensor produces at and at . Assuming a linear response, what pressure corresponds to an output of ?

33 During calibration, a robot sensor is compared with a reference instrument at several known input values. What is the main purpose of using several points?

34 A calibrated sensor consistently reads higher than the reference over its entire useful range. Which correction is most appropriate?

35 A displacement sensor has a sensitivity of . What output change should result from a displacement change of ?

36 A sensor gives different outputs at the same position depending on whether the position is approached from increasing or decreasing direction. This behavior is called:

37 A robot's joint encoder can distinguish angular changes as small as . Which characteristic does this value primarily describe?

38 A strain gauge forms one arm of a Wheatstone bridge and produces a very small differential voltage. Which signal-conditioning stage is most suitable first?

39 A sensor output ranges from to , but an ADC accepts to . Which conditioning operation uses the ADC range more effectively?

40 A robot's force measurement contains rapid fluctuations, while the actual force changes slowly. Which filter is generally most appropriate?

41 A robotic joint uses a magnetoresistive device whose electrical resistance changes with shaft angle. A signal-processing circuit converts this resistance into a digital position value. Which statement most accurately identifies the sensing chain?

42 A force sensor is mounted between a robot wrist and its tool. Its output changes when the tool accelerates, even though the external contact force is constant. Which interpretation is most appropriate?

43 A range sensor has a constant offset, a gain error proportional to distance, and a slowly varying temperature-dependent drift. Which classification is correct?

44 A position sensor has independent Gaussian noise with standard deviation and a calibration bias of . If the bias is uncorrected, what is the root-mean-square error?

45 A robot's proximity sensor reports valid values during normal operation but occasionally produces a large impossible reading after an electromagnetic discharge. How should this error primarily be classified?

46 A robot must detect a rapidly closing obstacle using a sensor with a response time and a controller sampling period of . Which conclusion is most defensible?

47 Two range sensors observe the same target. Sensor A has lower noise but a narrow field of view; Sensor B has higher noise but a wide field of view. For collision avoidance near corners, which design choice is most justified?

48 Which architecture best distinguishes a smart sensor from a conventional sensor followed only by an external ADC?

49 A smart inertial sensor performs temperature compensation using an internal model, timestamps each sample, and reports a confidence estimate over a bus. Which function most directly improves interoperability rather than measurement accuracy?

50 A nonlinear displacement sensor is calibrated at five reference positions. The residuals change sign several times across the range, and a straight-line fit has small endpoint errors but large midrange errors. Which calibration model is most appropriate?

51 A temperature-sensitive force sensor is calibrated at three temperatures and four loads per temperature. The calibration data show both temperature-dependent offset and temperature-dependent sensitivity. Which model captures both effects?

52 A calibrated sensor is highly repeatable, but its readings differ depending on whether the input approaches a reference value from above or below. Which procedure is required to characterize the dominant effect?

53 A sensor output changes from to when the measurand changes from to units. Around the operating point, a -unit change produces a detectable change. What are the average sensitivity and approximate resolution?

54 A first-order sensor has time constant . Approximately how long after a step input does its output reach of the final value?

55 A robot uses a sensor whose sensitivity decreases by per degree Celsius. Its nominal sensitivity is at . What sensitivity should be expected at , assuming a linear temperature coefficient?

56 A bridge sensor produces a differential signal of riding on a common-mode voltage of . The ADC accepts to . Which conditioning stage is most suitable before conversion?

57 A sensor has output impedance and is connected to an ADC input with . Ignoring other effects, what fraction of the sensor voltage reaches the ADC?

58 An ADC has a to input range and 12-bit resolution. A conditioned sensor output spans to . Approximately how many ADC codes represent the sensor's full physical range?

59 A white-noise voltage source has noise density . If an ideal low-pass filter limits the equivalent noise bandwidth to , what is the RMS noise voltage?

60 A robot estimates velocity by differentiating a noisy position signal. Which change is most likely to reduce noise amplification while preserving useful motion information?