Unit 5: Robot Tactile Sensors - Practice Quiz

1 What is the main purpose of a touch sensor in a robot?

2 Which type of signal is commonly produced by a simple push-button touch sensor?

3 What happens when a normally open touch switch is pressed?

4 Which robot application commonly uses a touch sensor?

5 A touch sensor is also commonly called a __ sensor.

6 What do tactile sensors mainly detect?

7 Which sense of humans is most closely related to robotic tactile sensing?

8 What physical quantity can a force-sensitive tactile sensor measure?

9 Where might tactile sensors be placed on a robotic hand?

10 Which information can tactile sensing help a robot obtain during gripping?

11 What is the purpose of interfacing a tactile sensor with a robot controller?

12 Which device commonly reads the electrical output of a tactile sensor?

13 An analog tactile sensor usually provides a signal that can have:

14 Which component can convert an analog tactile signal into digital data?

15 Why is calibration often performed when interfacing a tactile sensor?

16 What is a tactile array sensor?

17 What can a tactile array help a robot determine?

18 How are sensing elements in a tactile array usually arranged?

19 A tactile array with more sensing elements generally provides:

20 What does a dynamic tactile sensor mainly detect?

21 A robot gripper must detect whether an object has been contacted, but it does not need to measure the contact force. Which sensor is most appropriate?

22 A normally open touch switch is mounted on a robot finger. What happens to its output when the finger contacts an object?

23 A robot uses a mechanical touch switch that produces several rapid transitions when pressed. Which technique is most suitable for preventing false detections?

24 A capacitive touch sensor is installed near a metal robot frame and gives false triggers. Which change is most likely to improve its reliability?

25 What is the main advantage of a tactile sensor over a simple touch switch in robotic manipulation?

26 A robot must distinguish between a firm grasp and a grasp that is beginning to slip. Which tactile measurement is most useful?

27 A tactile sensor uses a compliant elastomer layer over sensing elements. What is the primary purpose of the elastomer?

28 A tactile sensor gives different readings for the same force when it is loaded and unloaded. Which characteristic does this behavior represent?

29 A robot fingertip must detect very small contact forces while supporting a moderate maximum load. Which sensor specification should receive the greatest attention?

30 A resistive tactile sensor changes resistance with applied pressure. Which interface circuit is commonly used to convert this change into a measurable voltage?

31 An analog tactile sensor has a useful bandwidth of . Which sampling frequency is most appropriate to reduce aliasing?

32 A microcontroller reads a tactile sensor using a 10-bit ADC with a 5 V reference. Approximately what voltage change corresponds to one ADC count?

33 Several tactile sensors share one analog-to-digital converter through an analog multiplexer. What is the main requirement for obtaining reliable readings?

34 A tactile sensor signal contains high-frequency electrical noise. Which interface method is most suitable before sending the signal to the ADC?

35 A tactile array contains a grid of sensing elements. How many individual contact locations can it represent if each element is read independently?

36 A tactile array is used to locate the center of pressure on a robot palm. Which processing method is most appropriate?

37 In a row-column scanned tactile array, one row is activated at a time while columns are measured. What is the main benefit of this arrangement?

38 A tactile array shows a pressure reading at a neighboring cell even when only one cell is pressed. What is this effect commonly called?

39 What feature distinguishes a dynamic tactile sensor from a purely static pressure sensor?

40 A robot needs to detect the instant an object strikes its fingertip. Which sensor behavior is most valuable for this task?

41 A normally closed mechanical touch sensor is used as a robot safety interlock. The controller input has a pull-up resistor, while the switch connects the input to ground during normal operation. Which condition should the controller interpret as a fault?

42 A robot bumper switch closes when its spring is compressed by . The spring stiffness is , and a linkage transmits only of the external normal force to the spring. Neglecting friction, what external force activates the switch?

43 A mechanical touch switch may bounce for up to . The controller samples it every and declares activation after consecutive active samples. What is the smallest that guarantees a bounce interval no longer than cannot itself be accepted as a stable activation?

44 Two redundant touch switches on a robot bumper should detect both an obstacle and any single open-circuit wiring fault. Which interface arrangement best supports this requirement?

45 A piezoresistive tactile element has resistance and forms the lower resistor of a divider with a fixed resistor , driven by . Which expression gives the measured divider voltage across the tactile element?

46 A capacitive tactile sensor is read through a long cable whose parasitic capacitance varies as the robot moves. Which design most directly reduces force-estimation error caused by that variation?

47 A tactile pad exhibits creep: under a constant applied force, its output slowly increases. A calibration derived only from rapidly applied loads will most likely cause which error during prolonged grasping?

48 An optical tactile sensor estimates normal force from marker displacement. During contact, all observed markers translate almost equally without appreciable relative deformation. Which interpretation is most defensible?

49 A passive resistive tactile array is scanned as an unisolated row-column matrix. Pressing three taxels at three corners of a rectangle causes the fourth corner to appear active. Which modification most directly eliminates this ghost activation?

50 An ADC has a sample capacitor and must settle to within LSB of a 12-bit result after a full-scale input step. Ignoring switch resistance, approximately what maximum source resistance permits settling within ?

51 A multiplexer alternates between a low-impedance reference channel and a high-impedance tactile channel. The first ADC conversion after each channel change is consistently biased toward the previous channel. What is the most effective firmware correction when hardware cannot be changed?

52 A full bridge tactile sensor has sensitivity at full load and is excited by . An instrumentation amplifier drives a ADC centered at . What is the largest ideal gain that preserves both positive and negative full-load signals?

53 A one-dimensional tactile array has taxel pitch . A sinusoidal pressure pattern has spatial wavelength . What is the principal sampling consequence?

54 A contact centroid is estimated by . Several central taxels saturate while edge taxels remain unsaturated. Compared with the true pressure centroid, what bias is most likely?

55 A calibrated tactile array obeys , where models taxel crosstalk. Direct inversion produces large oscillations because is ill-conditioned. Which estimator is most appropriate?

56 A tactile array must provide complete frames at . Each taxel requires one ADC conversion, and no parallel conversion is available. Ignoring overhead, what minimum ADC conversion rate is required?

57 A piezoelectric dynamic tactile sensor is connected to an ideal charge amplifier and subjected to a force step that is then held constant. Which output behavior best matches the sensor's intended dynamic response?

58 A dynamic tactile sensor is used to detect slip signatures up to . Its analog front end has negligible attenuation above that frequency. Which sampling configuration is sufficient to avoid aliasing of all input components below ?

59 A piezoelectric tactile element generates charge , where . It is connected to an ideal inverting charge amplifier with feedback capacitance . What output change results from a rapid force increase?

60 A dynamic tactile sensor and its interface are modeled by . Which operation best reconstructs force from the measured signal over the usable frequency band?