Cyber-Physical System Components

A cyber-physical system (CPS) combines computation, communication, and physical processes. Its main components are:

1. Plant
   • Sensors
   • Actuators
2. Controller
3. Wireless network
   • Connects multiple nodes and carries data and control flows

The plant sends sensed data to the controller. After computing a control decision, the controller sends a control flow back to the plant’s actuators. These components communicate through the wireless network.

flowchart LR
    P[Plant] -- Sensed data --> N[Wireless network]
    N --> C[Controller]
    C -- Control command --> N
    N --> A[Actuator]
    A --> P
    

Inside the Wireless Network

Cyber layer: network manager

The network manager monitors and reconfigures the wireless network. After a configuration change, the network acknowledges the network manager.

Physical layer: controller and plant

The controller actuates the plant, while sensors measure the plant’s state and return observations to the controller.

When developing a CPS, the cyber and physical parts should be designed as one system. Joint design can reveal optimization opportunities that are missed when networking, computation, and control are considered independently.

Timing and Signal Processing

Engineers usually assign conservative deadlines to sensing and control flows so that the system remains safe under worst-case conditions.

Fourier analysis is useful for decomposing and processing sensor signals, while control theory determines how the system should respond to those signals.