For current power supply systems in internal combustion engine (ICE) vehicles, there exists a lack of comprehensive monitoring and sufficient management. There is no effective fault diagnosis and fault-tolerant protection either. With increasing number of devices applied in ICE vehicles, power supply system of vehicle is in desperate need of improvement. In this study, a novel in-vehicle intelligent electric power supply network with comprehensive on-board fault diagnosis and real-time fault-tolerant protection is proposed. Firstly, the architecture of in-vehicle intelligent electric power supply network is established, making the power supply process of all devices smarter. Then, a hybrid-signal-based method is presented for on-board detection of multifarious faults, and over-temperature failure of wiring harness is detected based on the proposed real-time temperature evaluation model of wiring harness. Furthermore, a multi-level fault-tolerant protection method is proposed based on redundant design, to achieve power supply security and avoid false protection. Finally, tests are performed on the vehicle as well as test bench to verify the feasibility and reliability of the proposed power supply network. The results reveal that each device's power supply process is appropriately monitored, online detection of faults is successfully achieved, and the fault-tolerant method is able to realize remediation and protection in real time.

Tracked vehicles have been widely used in construction, agriculture, and the military. Major problems facing the industry, however, are high emissions and fuel consumption. Hybrid electric tracked vehicles have thus become increasingly popular because of their improved fuel economy and reduced emissions. While the series hybrid system has drawn the most attention and has been applied in most cases, the low efficiency caused by energy conversion losses and large propulsion motors has limited its development. A novel multi-mode powertrain with two output shafts controlling each side of the track independently is first proposed. The powertrain is a three-planetary-gear power-split system with one engine, three motors, and an ultracapacitor pack. Compared with the existing technologies, the proposed powertrain can realize skid steering without an extra steering mechanism, and significantly improve the overall efficiency. To demonstrate the advantages of the novel powertrain, a topology-control-size integrated optimization problem is solved based on drivability, fuel economy, and cost. Final simulation results show that the optimized design with downsized components can produce about a 30% improvement in drivability and a 15% improvement in fuel economy compared with the commonly used series hybrid benchmark. Moreover, the optimized design is verified to be much more economical taking cumulative cost into account, which is very attractive for potential industrial applications in the future.

Hybrid tracked vehicles are common in construction, agriculture, and military applications. Most use a series hybrid powertrain with large motors and operate at a relatively low efficiency. Although some researchers have proposed power-split powertrains, most of these would require an additional mechanism to achieve skid steering. To solve this problem and enhance drivability, a single-mode power-split hybrid powertrain for tracked vehicles with two outputs connected to the left and right tracks is proposed. The powertrain with three planetary gears (PGs) would then be able to control the torque on the two tracks independently and achieve skid steering. This powertrain has three degrees-of-freedom (DOF), allowing for control of the output torques and the engine speed independently from the vehicle running speed. All design candidates with three PGs are exhaustively searched by analyzing the dynamic characteristics and control to obtain the optimal design. Efficient topology design selection with parameter sizing and component sizing is accomplished using the enhanced progressive iteration approach to achieve better fuel economy using downsized components.