In recent years, small-scale turbojet engines (also known as microturbines) have seen wide use in numerous fields, from the propulsion system of fixed wing Unmanned Aerial Vehicles (UAVs) to electrical power generation, to acting as starter engines of big turbojets. Such various applications have different demands, such as speed, heat or mass flow. To fulfill these demands, it is important to drive the engine so that it follows the desired shaft speed closely, this may be accomplished through precise control of the fuel flow by an Engine Control Unit.
There are many ways to control the shaft speed of the micro jet controlling the quantity of fuel flow through the fuel pump. Classical control methods as state space, Sliding Mode Control (SMC), robust control and Proportional-Integral-Derivative control (PID) are used in industrial applications, including turbojet engines. Such methods are suitable and have well-established design to control turbines for UAVs, for example, in target drone operations. The PID control automatically applies an accurate and responsive correction to a control function, having a simple way to control the engine speed. Due to the nonlinear nature of turbojets, it is necessary to do gain scheduling to have an effective control in each operating point of the engine.
ECU block integration in Veronte Programs
The main function of this new block integrated in the Veronte Programs tool is to be able to satisfy the motor power demand coming from the autopilot without a physical device onboard (ECU). If the autopilot demands 50% of the maximum power to complete a maneuver or a mission, the block will be able to command the fuel pump the right fuel flow to reach that power.
Besides, it is very important to protect the engine from compressor surge, over temperature, or burner blowout. To do this, the new ECU block in Veronte Autopilot has the ability to control accelerations and decelerations of the engine shaft, just as Exit Gas Temperature, maintaining the integrity of the engine in any phase of the flight.
The integration of this block in Veronte makes it even more versatile, having the ability to control and integrate the propulsion system of fixed wing platforms and target drones, without the need of a physical ECU. Besides, there is the possibility to do an accurate gain scheduling through the versatile configuration of the block tough a user friendly software, Veronte Pipe.