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A linear engine type with piston assembly that swings between two oppositely placed combustion chambers considered in this study. The study investigated the effect of injection timing on starting of the engine. The injection position varied at five different positions (17mm to 27mm) before the maximum switching limit of the engine reached. It was observed that advancing the injection position in free-piston engine slows down the compression stroke and increases the combustion duration. Furthermore, lower peak pressure and rate of heat release occurred at 17 mm, 20 mm, and 23 mm injection timing. Relatively stable operation of the engine was achieved at 25 mm.

This manuscript presents an intelligent control design for the helical trajectory tracking of an underactuated quadrotor. One may see that the entire kinematics and dynamics are derived using Newton Euler approach. Since the quadrotor is one of the nonlinear and underactuated systems (where degree of freedom is greater than the number of control inputs) and with the induction of unmodeled dynamic factors and uncertainties, it is a highly unstable system. To stabilize, the linear extended state observer is proposed along with dual‐loop single dimension fuzzy‐based sliding mode control (DLSDF‐SMC). The entire system has been partitioned into two subsystems, that is, translational and rotational subsystems. Within the rotational subsystem, the attitude controller is proposed using DLSDF‐SMC, whereas for translational subsystem, paper proposes the position control design based on the hyperbolic functions to avoid the gimbal lock and an issue of singularity. The simulation work for proposed algorithm is performed using MATLAB and Simulink that are compared with conventional sliding mode control (SMC) and fuzzy‐based SMC control techniques. In addition to this, one may also find the hardware configuration that validates the software results. [ABSTRACT FROM AUTHOR]

The evident change in the design of the autopilot system produced massive help for the aviation industry and it required frequent upgrades. Reinforcement learning delivers appropriate outcomes when considering a continuous environment where the controlling Unmanned Aerial Vehicle (UAV) required maximum accuracy. In this paper, we designed a hybrid framework, which is based on Reinforcement Learning and Deep Learning where the traditional electronic flight controller is replaced by using 3D hand gestures. The algorithm is designed to take the input from 3D hand gestures and integrate with the Deep Deterministic Policy Gradient (DDPG) to receive the best reward and take actions according to 3D hand gestures input. The UAV consist of a Jetson Nano embedded test bed, Global Positioning System (GPS) sensor module, and Intel depth camera. The collision avoidance system based on the polar mask segmentation technique detects the obstacles and decides the best path according to the designed reward function. The analysis of the results has been observed providing best accuracy and computational time using novel design framework when compared with traditional Proportional Integral Derivatives (PID) flight controller. There are six reward functions estimated for 2500, 5000, 7500, and 10000 episodes of training, which have been normalized between 0 to -4000. The best observation has been captured on 2500 episodes where the rewards are calculated for maximum value. The achieved training accuracy of polar mask segmentation for collision avoidance is 86.36%. [ABSTRACT FROM AUTHOR]

Parallel hybrid electric vehicles (HEV) can be classified according to the location of the electric motor with respect to the transmission unit for the internal combustion engine (ICE): they can be pre-transmission or posttransmission parallel hybrid. A split-axle parallel HEV – in which the ICE and electric motor provide propulsion power to different axles – is a sub-type of the post-transmission hybrid, since addition of torque and power from the two power sources occurs after the vehicle’s transmission. The term ‘through-the-road’ (TTR) hybrid is also used for the split-parallel HEV, since power coupling between the ICE and electric motor is not through some mechanical device but through the vehicle itself, its wheels and the road on which it moves. The present work presents torquespeed relationship of the split-parallel hybrid and analyses simulation results of torque profiles and acceleration performance of pre-transmission and post-transmission hybrid configurations, using three different sizes of electric motor. Different operating regions of the pre-trans and post-trans motors are observed, leading to different speed and torque profiles. Although ICE average efficiency in the post-trans hybrid is slightly lower than in the pre-trans hybrid, the post-trans hybrid vehicle has better fuel economy and acceleration performance than the pre-trans hybrid vehicle.