Mechatronics Fundamentals: Sensors, Actuators and Motors Explained
1. What is Mechatronics? b. The integration of mechanical, electrical, and computer systems
2. Which of the following is NOT an advantage of Mechatronic systems? c. Increased complexity
3. Why does an Anti-lock Braking System (ABS) qualify as a true mechatronic system, while a traditional mechanical drum brake does not? b. ABS integrates wheel speed sensors, an ECU controller, and hydraulic actuators in a closed loop
4. What is the primary purpose of Mechatronic systems? c. To integrate mechanical, electrical, and computer systems
5. The function of a transducer is to convert a. one form of energy into another form of energy
6. What is the role of a sensor in a Mechatronic system? a. To convert physical quantities into electrical signals
7. A load cell is essentially a a. strain gauge
8. In semiconductor strain gauges, the change in resistance on application of strain is mainly on account of change in? c. resistivity
9. Piezo-electric transducers are d. both (a) and (c).
10. What does an optical encoder do in a Mechatronic system? c. Determines rotational position, speed and direction
11. Which type of sensor is suitable for detecting the presence or absence of an object without physical contact?
b. Proximity sensor
12. When selecting a sensor for a Mechatronic system, what factors should be considered? a. Cost, size, and power requirements
13. How does a tactile sensor differ fundamentally from an optical or inductive proximity sensor? a. A tactile sensor requires physical mechanical contact with a surface to respond, whereas a proximity sensor detects presence across an air gap without touch
14. In which application is a capacitive level sensor most suitable? b. Detecting liquid levels in a container
15. What is the primary function of a tactile sensor? b. Detecting force or pressure or touch
16. Which type of sensor is commonly used in touchscreens and touch-sensitive devices? d. Capacitive touch sensor
17. Which of the following best describes the integration of mechanical, electrical, and computer systems in Mechatronics? c. Mechanical, electrical, and computer systems work together seamlessly.
18. What advantage does a Mechatronic system offer in terms of flexibility and adaptability? b. It can adapt to different tasks and environments.
19. In Mechatronic systems, what is the primary role of the computer component? c. To control and coordinate the operation of all components
20. Which of the following is an example of a Mechatronic system used in the automotive industry? c. An automatic transmission system
21. Which of the following additional components is required for measuring pressure with a piezoelectric crystal? a. Bellows
22. LVDT is a? c. Inductive transducer
23. Piezoelectric crystals produce an e.m.f. a. when external mechanical force is applied
24. Which of the following sensors is used for detecting the presence of an object or person in a room? b. Proximity sensor
25. Angular velocity is measured by c. Tachogenerator
26. Which of the following is not a temperature sensor? b. LVDT
27. When selecting a sensor for a Mechatronic application, what does the “range” refer to? b. The maximum and minimum values it can measure
28. Which of the following factors is essential for sensor selection when designing a safety critical Mechatronic system? c. Reliability
29. Which of the following is a dynamic characteristic of a transducer? d. Response time
30. A strain gauge with an initial resistance of 350 ohm and a gauge factor of 2.1 shows a resistance increase of 0.147 ohm under load. What is the strain experienced by the test specimen? b. 0.0002
Comparing Pneumatic Systems and Hydraulic Systems
Compare Pneumatic Systems and Hydraulic Systems. Pneumatic systems use compressed air, whereas hydraulic systems generally use pressurized oil to transmit power.
Parameter | Pneumatic system | Hydraulic system |
|---|---|---|
Working fluid | Compressed air | Oil |
Operating pressure | Generally lower | Generally higher |
Force output | Low to medium | Very high |
Speed | Often fast | Good controlled movement under heavy loads |
Accuracy | Lower due to air compressibility | Better under varying loads |
Cost | Generally lower | Generally higher |
Leakage | Air leakage is usually cleaner | Oil leakage can cause contamination |
Maintenance | Relatively simple | Requires fluid and leak management |
Tubing | Often flexible plastic | Usually pressure-rated metal tubing |
Applications | Pick-and-place, clamping, packaging | Heavy presses, lifting and construction machinery |
Conclusion: Pneumatics are suitable for fast, light-duty operations, while hydraulics are preferred for heavy loads and high-force applications.
DC Motor Working and Industrial Applications in Mechatronics
1. Explain the working of a DC Motor with industrial applications in Mechatronics. A DC motor converts electrical energy into mechanical rotational energy.
Neat diagram:
Main parts: 1) Stator: Produces the magnetic field. 2) Armature: Rotating coil carrying current. 3) Commutator: Reverses armature current at the appropriate time. 4) Brushes: Supply current to the rotating armature. 5) Shaft: Transfers mechanical power to the load.
Working principle: When a current-carrying conductor is placed in a magnetic field, it experiences a force.
F = BIL
1) DC supply is provided to the armature through brushes and commutator. 2) The current-carrying armature conductors experience forces in the magnetic field. 3) These forces produce torque and rotate the armature.
4) The commutator reverses the current direction in the conductors at the correct time, maintaining rotation in the same direction. 5) Back EMF is generated during rotation and opposes the applied voltage.
Industrial applications in Mechatronics: 1) Robotic arms and mobile robots. 2) Conveyor belt systems. 3) Electric vehicles. 4) CNC machines and positioning systems. 5) Automated material-handling equipment.
AC Motor Working, Sketch and Advantages
Explain the working of an AC Motor with a neat sketch and state its advantages.
Definition: An AC motor converts alternating electrical energy into mechanical rotational energy.
Neat sketch:
Main parts: 1) Stator: Stationary part containing AC windings. 2) Rotor: Rotating part mounted on a shaft. 3) Air gap: Small gap between stator and rotor. 4) Bearings and shaft: Support and transfer rotation.
Working of a three-phase induction motor: 1) A three-phase AC supply is applied to the stator windings. 2) The stator produces a rotating magnetic field. 3) This field cuts the rotor conductors and induces current in them.
4) The interaction between the rotating magnetic field and rotor current produces electromagnetic torque. 5) The rotor starts rotating in the same direction as the rotating magnetic field. 6) The rotor runs slightly below synchronous speed, allowing induction to continue.
Synchronous speed is:
Ns = 120f / P RPM, where f is supply frequency and P is the number of poles.
Advantages: 1) Rugged and reliable construction. 2) Low maintenance. 3) Generally economical. 4) Good efficiency.
Applications: Pumps, compressors, conveyors, fans, machine tools and industrial automation.