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The current paper proposes a hydraulic interconnected suspension system (HIS) based on a hydraulic energy-regenerative shock absorber (HESA) comparatively with the passive suspensions. The structure and working principles of the HIS system are introduced in order to investigate the damping performance and energy regeneration characteristics of the proposed system. Then, the dynamic characteristics of the HIS-HESA system have been investigated based on a 4-DOF longitudinal half vehicle model. In the simulation, two different road inputs were used in the dynamic characterization of the HIS-HESA; the warp sinusoidal excitation, and the random road signal. In addition, a comparative analysis was provided for the dynamic responses of the half vehicle model for both the HIS-HESA and the conventional suspension. Furthermore, a parametric analysis of the HIS-HESA has been carried out highlining the key parameters that have a remarkable effect on the HIS-HESA performance.

The closed cabin temperature is anticipated to be cooled down when it is a bit hot inside the driving car. The traditional air-condition lowers the cabin temperature by frequently switching the status of the compressor, which increases the engine’s parasitic power and shortens the compressor’s service-life. The semiconductor auxiliary cooling system with the properties of no moving parts, high control precision and quick response has the potential to assist the on-board air-condition in modulating the cabin temperature with relative small ranges. Little temperature differences between the cabin and the outside environment means that the system energy consumption to ensure the occupant comfort is relatively low and the inefficiency could be made up by the renewable energy source.

In this paper a new pressure control method of a modified accumulator-type Electro-hydraulic Braking System (EHB) is proposed. The system is composed of a hydraulic motor pump, an accumulator, an integrated master cylinder, a pedal feel simulator, valves and pipelines. Two pressurizing modes are switched between by-motor and by-accumulator to adapt different pressure boost demands. A differentiator filtering raw sensor signal and calculating pedal speed is designed. By using the pedal feel simulator, the relationship between wheel pressures and brake force is decoupled. The relationships among pedal displacement, pedal force and wheel pressure are calibrated by experiments. A model-based PI controller with predictor is designed to lower the influences caused by delay. Moreover, a self-tuning regulator is introduced to deal with the parameter’s time-varying caused by temperature, brake pads wearing and delay variation.

Vehicle hydraulic retarders are applied in heavy-duty trucks and buses as an auxiliary braking device. In traditional cooling systems of hydraulic retarders, the working fluid is introduced into the heat exchanger to transfer heat to the cooling liquid in circulation, whose heat is then dissipated by the engine cooling system. This prevents the waste heat of the working fluid from being used effectively. In hydraulic retarder cooling system based on the Organic Rankine Cycle, the organic working fluid first transfers heat with the hydraulic retarder working fluid in Rankine cycle, and then outputs power through expansion machine. It can both reduce heat load of the engine cooling system, and enhance thermal stability of the hydraulic retarder while recovering and utilizing braking energy. First of all, according to the target vehicle model, hydraulic retarder cooling system model based on Rankine cycle is established.

This paper presents a novel application of hydraulic electromagnetic energy-regenerative shock absorber (HESA) into commercial vehicle suspension system and vehicle road performance are simulated by the evaluating indexes (e.g. root-mean-square values of vertical acceleration of sprung mass, dynamic tire-ground contact force, suspension deflection and harvested power; maximum values of pitch angle and roll angle). Firstly, the configuration and working principle of HESA are introduced. Then, the damping characteristics of HESA and the seven-degrees-of-freedom vehicle dynamics were modeled respectively before deriving the dynamic characteristics of a vehicle equipped with HESA. The control current is fixed at 7A to match the similar damping effect of traditional damper on the basis of energy conversion method of nonlinear shock absorber.

With the improvement of occupants’ awareness on the driving safety, hydraulic retarder applications increase quickly. The traditional hydraulic retarder, on the one hand, exhausts the waste heat of transmission oil by the engine cooling system; on the other hand, the engine power should be consumed to drive the water pump and the engine cooling fan for maintaining the normal operation of the auxiliary braking system. In this study, the Organic Rankine Cycle (ORC) instead of the traditional hydraulic retarder water-cooling system is applied to achieve the effective temperature control of the hydraulic retarder, while the waste heat of transmission oil could be recovered for saving vehicle energy consumption. The ORC fluid selection needs comprehensive consideration for the net power of the ORC and the optimal temperature range of the retarder transmission oil at both the inlet and outlet end, which is the key issue to ensure the stability and efficiency of the ORC system performance.

Vehicle exhaust waste-heat recovery with thermoelectric power generators can improve energy efficiency, as well as vehicle fuel economy. In the conventional structure, the hot-end of thermoelectric module is directly connected with the outer wall of the exhaust pipe, while the cold-end is connected with the water pipe’s outer wall of the vehicle engine cooling cycle. However, the variety of vehicle engine operating conditions leads to the instability of the hot-end temperature, which will reduce the generating efficiency of the thermoelectric modules and also shorten its service life. This research is on the basis of constructing a heat transfer oil circulation, and to study the action principles and implementation methods of it.

Eddy current retarder (ECR) shares a large market of auxiliary brakes in China, but shortcomings of the short continuous braking time and the high additional energy consumption are also obvious. The propose of combined braking partakes the braking torque of ECR. However, the existed serial-parallel braking strategy could hardly balance well the relationship between the braking stability and the energy recovery efficiency. This research puts forward an energy management strategy of combined braking system which aims to maximize energy recovery while ensure the brake stability. The motor speed, the braking request and the state of charge (SoC) of the storage module are analyzed synthetically to calculate the reasonable braking torque distribution proportion. And the recovered energy is priority for using in the braking unit to reduce the additional energy consumption in this strategy.

The hydraulic retarder is an auxiliary braking device used in heavy duty vehicle. It generates braking forceby liquid damping effect and makes inertial energy into thermal energy of the transmission medium when the vehicleis in thedownhill. The traditional thermal management system of the hydraulic retarder dissipates the heat of transmission medium out of the vehicle directly, which causes a big waste of energy, meanwhilethe thermal management system components need to consume engine power. This study applies organic Rankine cycle (ORC)cooling system to meet the high power cooling requirements of the hydraulic retarder and recover waste heat energy from the transmission medium at the same time and then supply energy to the thermal management system, which could save the parasitic power of the engine and improve the comprehensive energy utilization ratio of the vehicle.

Nowadays, off-highway vehicles enjoyed a significant status in the national defense and civil construction. There is no doubt that the working conditions of off-highways are quite different from the conventional passenger cars, hence, their suspensions are particularly designed. Since the hydro-pneumatic suspension technology is maturely applied in engineering machinery, this paper presents a concept for a novel energy-harvesting device, which is applied in off-highway vehicles based on hydro-pneumatic suspension, namely, electro-hydraulic energy-harvesting suspension (EHEHS). The EHEHS took the fundamental of mechanism-electronic-hydraulic system, which consisted the following elements: a cylinder, 2 check valves, a hydro-pneumatic spring, a hydraulic motor, a DC motor, a processing circuit and a battery. In the EHEHS system, the cylinder is used to transmit the vibration energy into hydraulic energy, which is stored in hydro-pneumatic spring.

To integrate the energy-recovery characteristic of the Hydraulic electromagnetic shock absorber (HESA) and the anti-roll characteristic and anti-pitch characteristic of Hydraulic Interconnected Suspension(HIS), a Hydraulic Interconnected Suspension system based on Hydraulic Electromagnetic Shock Absorber (HESA-HIS) is presented. HESA-HIS has three operating modes: energy-recovery priority mode, dynamic performance priority mode and energy-recovery and dynamic performance balance mode. The working principle of HESA-HIS in the three operating modes is introduced, a full vehicle model is built by using the software AMESim, and some simulation tests are conducted by using the vehicle model. The simulation results show that the system can effectively reduce the roll angle of the vehicle, while maintaining good ride performance. Fishhook test results show that the roll angle of the HESA-HIS vehicle is reduced by 80%, compared to the traditional vehicle.

The basic principle of wavelet transform is presented and the method of wavelet theory is used in vibration signal analysis of vehicle in this paper. The vibration signals which generated in the locations such as cab floor, engine, transmission, band spring and frame under the usual work condition are measured by the vibration test system. The vibration signals are decomposed with the principle of wavelet decomposition at level six, and eigenvectors of signal energy are gained. According to the correlation coefficient of eigenvectors of signal energy distribution, two signals correlativity is determined. It could be an effective method that identificate the main vibration source.

This paper presented a brief derivation of the energy dissipation by vehicle shock absorbers. Analysis between energy dissipation and damping coefficient, the road displacement power spectral density, the vehicle speed and the tire stiffness was carried out. Then an energy recovery scheme was put forward, and the bench test proved that the energy harvest scheme is feasible. In the end, this paper provided detailed derivation of the characteristics of the hydraulic electromagnetic energy-regenerative shock absorber, which increases its feasibility and practicability.

When vehicle traveling on the bumpy road or vehicle acceleration and deceleration, which will cause the body vibration of vehicle, at the same time, a large part of energy would be absorbed by the shock absorber transforms the mechanical energy into heat energy dissipated. In order to recycle the energy of vibration and keep the stability of running car, this paper provides the shock absorber of energy recovery that recycling the energy dissipated from the traditional absorber. The shock absorber includes rod and rodless chamber cavity, the two parts contain oil outlet and oil inlet, which connected to a bridge type loop of hydraulic to make pulsating oil pressure towards one direction, when the shock absorber vibration causes pulsating oil pressure, it drives hydraulic pump operation. Because the output shaft of the hydraulic pump fixedly attached to the input shaft of generator, so the generator produces electricity for recycling energy[1].

Semi-active suspension has been widely applied in commercial vehicle suspension in order to get good riding comfortableness. Fuzzy logic control (FLC) has been widely applied in the field of kinetic control because control rule of FLC is easy to understand. But the gain of fuzzy rules and adjustment of membership functions usually depend on experts' experiences and repeated experiments, thus the fuzzy rules and membership functions has strong subjectivity, also are easily affected by environment of experiments, so the main problem of fuzzy logic controller design is selection and optimization of fuzzy rules and membership functions. Genetic Algorithms (GA) is the algorithm that searches the optimal solution through simulating natural evolutionary process and is one of the evolution algorithms which have most extensive impact.