Actuators

ME5410 Lesson 8

penway
Last updated on Oct 23, 2023 1 min read Course Notes, ME5410

Actuator: accept control command, produce a change in the physical system by generating {force, heat, flow, etc} Energy -> Motion, etc

Actuator = Trannsducer(Must) + Energy Source(Optional) + Motion Converter(Optional)

Rotary vs Linear Tethered (external power, control sys) vs Untethered (onboard power and control sys) Hard vs Soft

Classification on Actuation Mechanisms

  1. Electrical

    • two state: on/off, like electrically operated switch

  2. Electromechanical

    • DC, AC, Stepper Motor
    • Linear/rotary, Hard, Tethered

  3. Electromagnetic

    • DC/AC solenoid (Linear)
    • Linear/rotary, Hard, Tethered

  4. Hydraulic(液压) and 5. Pneumatic(气动)

    • Hy: pressurized oil, Pn: pressurized gas
    • Rotary: low speed high torque
    • Linear piston
    • Control valve ** The above are all Linear/rotary, Hard, Tethered ** X. Smart Materials

Elastic Actuator

Linear/rotary, Hard, Tethered, hard but elastic

Electric motor: Encoder + Reducer (Gearbox) + Power Amplifier + Motor + Control Unit

[Can be important] Actuator Selectioin Criteria

  • Couninuous Power Output
  • Range of Motion
  • Resolution
  • Accuracy
  • Peak force/torque
  • Heat dissipation
  • Speed characteristics: Force(torque) - speed curve
  • No load speed
  • Frequency response
  • Power requirement

Soft Actuation (almost =) Artificial Muscle

  • Pneumatic 一些有趣的，气球，
    • McKibben Artificial Muscle
    • Micro McKibben，模拟肌肉纤维
    • 大象鼻子
  • phase transition
    • shape memory alloy
    • shape memory polymer: temp, humidity, light, driven
  • combustion
  • electrostatic force