Benchmark

In this section, we bring detailed explanations for the 3 AI-enabled CPS in our experiment.

1. Adaptive Cruise Control (ACC)

The system is released by Mathworks. This system targets to control the acceleration of the ego vehicle to keep the relative distance Drel to the lead car greater than a safety distance Dsafe. The safety distance is dynamically changed based on the relative velocity between two cars. In addition, when the safety distance is assured, the ego car should approach to use-set cruising velocity vtarget.

2. Abstract Fuel Control (AFC)

AFC is released by Toyota which simulates a powertrain system of a vehicle. The external inputs are pedal angle and engine speed, and the fuel injection rate to a fuel cylinder is controlled by the system. The air-fuel-ratio AF inside the cylinder is required to maintain a reference value AFref to achieve complete gasoline fuel combustion. The optimized stoichiometric air-fuel-ratio is about 14.7 and the deviation should be limited within 0.1.

3. Exothermic Chemical Reactor (CSTR)

CSTR is originally released by Mathworks which is a widely used system in various chemical industry domains. The concentration of the reagent in the exit stream of the reactor is expected to sustain the setpoint. When the reactor is triggered from a low transformation ratio to a high transformation ratio, the concentration setpoint will change accordingly. In addition, the error of the concentration should be less than 0.35 during the entire transformation.

4. Water Tank (WTK)

WTK is widely employed across multiple industrial fields to manage the inflow and outflow of water using a container. The water inflow rate from the top of the tank varies according to the voltage applied to the pump. Meanwhile, water exits the tank through a hole in the base at a rate that is proportional to the square root of the water level within the tank. The inclusion of the square root in the water flow rate introduces non-linearity to the system.

5. Steam Condenser (SC)

SC is a sealed container of modern steam power plants. The system’s objective is to keep the condenser’s internal pressure at a designated level, and the system’s internal pressure should remain below atmospheric pressure during this period. The system’s external input and output are the steam mass flow rate and the condenser’s internal pressure.

6. Wind Turbine (WT)

WT takes the wind speed as the input signal and produces outputs including blade pitch angle, generator torque, rotor speed, and the demanded blade pitch angle. The system aims to reach the maximum power point by altering operational modes to ensure the blade pitch angle complies with a reference value.

7. Highway Lane Following (HLF)

HLF is designed to keep a vehicle within a designated lane while maintaining either a set speed or a safe following distance from the vehicle ahead. It employs visual processing algorithms to detect lanes and surrounding vehicles via a camera, and the controller regulates the steering angle and the acceleration accordingly. The simulation environment is constructed using the Unreal Engine.