Page 532 - The Mechatronics Handbook

0066_Frame_C20 Page 2 Wednesday, January 9, 2002 5:41 PM

Communication Operator Interface

Information Processing
Low Power Electronics, Software
Actuators Sensors
Power Modulation, Energy Conversion,
Energy Conversion Signal Processing
Physical Process
Physical Process
Physical Process
High Power
mixture of mechanical, fluid,
thermal, chemical, electrical
components/subsystems
FIGURE 20.1 Mechatronic system.

Unmodulated
energy source

Power
Energy
Control Amplification Energy Load
Energy
Conversion
Signal Conversion Environment
& Modulation Conversion
Low Power High Power Actuator
FIGURE 20.2 Actuator functional diagram.

Ps

LOAD

Power
Control Low Amplification Energy Conversion
Signal Energy & Modulation
+V

LOAD

FIGURE 20.3 Electrohydraulic and electromechanical actuators.
with the load or physical environment. In addition, we will look at the electronic components that are
essential for modulating the necessary electrical energy.
From an energy perspective, a mechatronic system can be separated into a relatively higher energy
(power) portion that interacts with the physical world and a relatively low energy (power) portion that
process the data, see Fig. 20.1. Sensor and actuators are the interfacing devices that accomplish the tasks
of energy modulation and energy conversion. Therefore, an actuator can be viewed as having the
structure depicted in Fig. 20.2. Typically, actuators are considered only as energy conversion devices.
However, with the proliferation of power electronics, we will take a more inclusive view of actuators that
also includes power amplification. An electrohydraulic linear actuator, see Fig. 20.3, can also be similarly
classified, where the spool valve is the power amplification/modulation block with spool position as the

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