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We introduce an effective method to actively induce droplet generation using negative pressure. Droplets can be generated on demand using a series of periodic negative pressure pulses. Fluidic network models were developed using the analogy to electric networks to relate the pressure conditions for different flow regimes. Experimental results show that the droplet volume is correlated to the pressure ratio with a power law of 1.3. Using a pulsed negative pressure at the outlet, we are able to produce droplets in demand and with a volume proportional to the pulse width.

Summary The robust receding horizon control (RHC) synthesis approach is developed in this paper, for the simultaneous tracking and regulation problem (STRP) of wheeled vehicles with bounded disturbances. Considering the bounded disturbances, we firstly provide a robust positively invariant (RPI) set and associated feedback controller for the perturbed vehicles, which contribute to the foundation of the robust RHC synthesis approach. Then, by extending the tube‐based approach introduced in the article of Mayne et al (robust model predictive control of constrained linear systems with bounded disturbances in Automatica, 2005, vol. 41) to the STRP of wheeled vehicles, we employ the designed RPI set to determine the robust tube and terminal state region, and further construct a nominal optimal control problem. The actual control input is implemented by correcting the solved nominal input with the designed feedback controller. Following the contributed properties of the developed RPI set and extended tube‐based approach, a robust RHC algorithm is finally proposed with the guarantees of recursive feasibility and robust convergence, which can also be adapted for real‐time implementation. Additionally, due to the elaborate control design, the effect of disturbances can be completely nullified to achieve better tracking performance. The effectiveness and advantage of the proposed approach are illustrated by two simulation examples.

The trajectory control of autonomous vehicles is an area which has attracted much research recently because it can prevent accidents caused by driver errors and significantly improve road capacity. Overtaking is one of the most complex and challenging manoeuvres for road vehicles and the autonomous control of the vehicle during this manoeuvre can greatly improve vehicle safety. As the innovative four-wheel independent steering (4WIS) and four-wheel independent driving (4WID) electric vehicle can provide redundant control actuators, this study focuses on utilising 4WIS-4WID techniques and vehicle dynamics control to achieve better control of autonomous vehicles. This study first introduces the traditional two-wheel proportional-integral-derivative (PID) steering control and two-wheel sliding mode controller (SMC) driving control for autonomous vehicle control. Then based on these, the four-wheel PID steering controller and four-wheel SMC steering controller are proposed. A four-wheel SMC driving controller and a four-wheel combined yaw rate and longitudinal velocity SMC driving controller are also proposed. Simulation results prove that the best control performance can be achieved when the four-wheel SMC steering controller and four-wheel combined yaw rate and longitudinal velocity SMC driving controller are used together.

This study proposed a hybrid inductive and capacitive wireless power transfer system to achieve high-power transfer by combining inductive power transfer (IPT) and capacitive power transfer (CPT). A traditional IPT system imposes a high voltage on the transmitter because of resonance. Meanwhile, high voltages are required to establish an electric field to deliver power to the CPT system. Therefore, they can be combined to a hybrid system to achieve high-power transfer by utilising two power transfer paths. A general model of the hybrid IPT and CPT coupler is analysed in detail. With a series-series compensation topology, 1.1 kW hybrid system with equal power transferred by two paths is simulated and set up to evaluate the performance of the proposed method. An experimental prototype is built under various conditions, and the result shows that the hybrid system achieved 1.1 kW output power through both of magnetic path and of electric path successfully with 91.9% DC-DC efficiency.