Energy Management in Multi-Rotors Unmanned Aerial Systems

The energetic cost of high performances battery-powered applications; like multi-rotor Unmanned Aerial Systems (UASs); is one of the key challenges. The continuous evolution of electrical energy storage sources is overcome by the great amount of energy required by the multi-rotor unmanned aerial system. Therefore, the on-board energy is a critical factor that needs to be further investigated and well-managed. The rechargeable Lithium-Polymer battery has shown a great success in aerial robotics, thanks to its high energy density, small size, and weight. However, the overall performances of a Li-Po battery degrade over time. Consequently, it is indispensable to have an instantly accurate data of the current batteries status; particularly the state of charge; and their remaining lifetime. In this work, we are interested in managing the energy of a Li-Po battery-powered multi-rotor UAS. First, we start by describing the different battery's dynamic models found in the literature. Then, the focus shifts towards the Battery Monitoring System, which as its name indicates, monitors and maintains rechargeable batteries. It turned out that the heart of modern BMS is based on battery status estimation. The battery status is widely described by two parameters: State Of Charge (SOC) and the State Of Health (SOH). These two factors are of a critical concern in energy management of dynamic applications. Therefore, we will highlight the main techniques seen in literature used to estimate the SOC and SOH. To monitor on-board energy, an Energy Control System is suggested in this paper. The ECS is based on a BMS who will manage all problems that could meet the batteries and provide the supervisor system with essential information to succeed the multi-rotor UAS flight.