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Abstract In this article, a unique design for Hydro-Pneumatic Energy Harvesting Suspension HPEHS system is introduced. The design includes a hydraulic rectifier to maintain one-way flow direction in order to obtain maximum power generation from the vertical oscillation of the suspension system and achieve handling and comfort car drive. A mathematical model is presented to study the system dynamics and non-linear effects for HPEHS system. A simulation model is created by using Advanced Modeling Environment Simulations software (AMEsim) to analyze system performance. Furthermore, a co-simulation platform model is developed using Matlab-Simulink and AMEsim to optimize the PID controller parameters of the external variable load resistor applied on the generator by using Particle Swarm Optimization (PSO).

This paper describes the development and testing of a Dynamic Vibration Absorber to reduce frame beaming vibration in a highway tractor. Frame beaming occurs when the first vertical bending mode of the frame is excited by road or wheel-end inputs. It is primarily a problem for driver comfort. Up until now, few options were available to resolve this problem. The paper will review the phenomenon, design factors affecting a vehicle's sensitivity to frame beaming, and the principles of Dynamic Vibration Absorbers (AKA Tuned Mass Dampers). Finally, the paper will describe simulation and testing that led to the development of an effective vibration absorber as a field fix.

Ride is considered to be one of the crucial criterion for evaluating the performance of a vehicle. Automobile industry is striving for improvement in designs to provide superior passenger comfort in Commercial vehicles segment. In Industry, Quarter-car model has been used for years to study the vehicle’s ride dynamics. But due to lower DOF involved in quarter car, the output accuracy is somewhat compromised. This paper aims in development of a 7 DOF full-car Model to perform the ride- comfort analysis for Light Duty 4*2 Commercial Bus using MATLAB Simulink which can be used to tune the suspension design to meet the required ride-comfort criteria. Firstly, experimental data and Physical Parameters are collected by performing Practical Test on commercial Bus on different road profiles. Secondly, a Full Car Mathematical Model with 7 DOF has been developed for a bus using MATLAB Simulink R2018a.

Due to recent infrastructural development and emerging competitive automotive markets, there is seen a huge shift in customer’s demand and vehicle drivability pattern in commercial vehicle industry. Now apart from ensuring better vehicle durability and best in class tyre life and fuel mileage, a vehicle manufacturer also has to focus on other key attributes like driver’s safety and ride comfort. Thus, for ensuring enhanced drivability, key parameters for ensuring better vehicle handling includes optimization of bump steer and brake steer. Both bump steer and brake steer are vehicle’s undesirable phenomenon where a driver is forced to constantly make steering wheel correction in order to safely maneuver the vehicle in the desired path.

It is well known that the ride quality of trucks is much harsher than that of automobiles. Additionally, truck drivers typically drive trucks for much longer duration than automobile drivers. These two factors contribute to the fatigue that a truck driver typically experiences during long haul deliveries. Fatigue reduces driver alertness and increases reaction times, increasing the possibility of an accident. One may conclude that better ride quality contributes to safer operation. The secondary suspensions of a tractor have been an area of particular interest because of the considerable ride comfort improvements they provide. A gap exists in the current engineering domain of an easily configurable high fidelity low computational cost simulation tool to analyze the ride of a tractor semi-trailer. For a preliminary design study, a 15 d.o.f. model of the tractor semi-trailer was developed to simulate in the Matlab/Simulink environment.

In this paper, a multi-mode active seat suspension with a single actuator is proposed and built. A one-DOF seat suspension system is modelled based on a quarter car model of commercial vehicle with an actuator which is comprised of a DC motor and a gear reducer. Aiming at improving ride comfort and reducing energy consumption, a multi-mode controller is established. According to the seat vertical acceleration and suspension dynamic travel signals, control strategies switch between three modes: active drive mode, energy harvesting mode and plug breaking mode.

Present day truck cab suspension comprises fully floating linkage type cab suspension to facilitate ride comfort. Fully floating cab has certain limitations in terms of stability of cab in dynamic articulations during vehicle running especially in off-road terrain applications. Presence on linkages leads to more wear and tear of joints and bushes which will in turn provide detrimental effect on vibration levels of cab that affects ride comfort for occupants. There is a dire need to develop a system that provides improvement in lateral and vertical stability of cab without compromising ride comfort of occupants. Durability of the product also to be met till life of vehicle. Anti-Vibration Stability Cab Mount is an unsymmetrical mount designed by compounding of elastomeric(rubber) metal bonded outer sleeves sandwiched between multistage inner mount bonded on aluminum casing. Cabin front supports are hinged to mount along with housing providing proper alignment to cab after assembly.

In order to build a useful and comfortable in-car human machine interface systems, the information presentation method should be easy to understand (low mental workload) and one should be able to respond with ease to the information presented (low response workload). We are making efforts to establish an evaluation method that would differentiate between mental workload and response workload. Here, we present the results of our trial using brain waves measurements (Eye Fixation Related Potentials). We focus on the relation between P3 latencies and drivers response workload compared to mental workload in a task involving eye movements. Previous experiments showed that P3 latency correlates strongly with the amount of information presented. The current experiment shows that P3 latencies seem to be independent to the type of response the subject is requested to perform.

This paper presents a verification of the effectiveness of an image processing method, used to reduce the inconsistent speed perception caused by using the camera images in conjunction with side-view mirrors. Vision assistance technology using cameras is widely used in practical applications today. However, speed and distance perceived with camera images may differ from those viewed directly or viewed with conventional side-view mirrors. That is particularly evident in wide-angle camera images, and can easily cause a sense of discomfort experienced by the driver. A Side View Camera (SVC) shows images rearward and to the side that include the blind spots of side-view mirrors on an onboard display. It is a system to compensate side-view mirrors, broadening the driver's field of view to eliminate bind spots. SVC is used in conjunction with the side-view mirrors.

Abstract A dynamic model of a multi-unit air conditioning (AC) system in a generic bus was developed to investigate different control strategies on the system performance and the cabin comfort level. In this study, a part-load condition was considered, where adopting a proper strategy for governing a multi-unit system is important. Simulink and Simscape toolbox from MATLAB (R2019a) were used to build up the real-time model by integrating a cooling system with a cabin sub-model. The cooling system consists of two independently controlled units, based on a Vapor Compression Cycle (VCC). The cabin is modelled using a moisture air network and is coupled with the cooling system to exchange heat with the refrigerant through the evaporators. Moreover, the sensible and latent loads are incorporated into the cabin by a thermal network.

The current research in modern commercial vehicles has been focusing on occupant comfort and safety system, especially on noise, vibration, and harshness (NVH) studies. In that point of view, the current study analyzed the performance of a hybrid suspension system for light commercial passenger vehicles under different road surfaces. The mathematical model and the experimental investigation were carried out for the full car model under periodic and discrete road inputs. The output parameters, like the driver seat acceleration, body acceleration, suspension travel, tire displacement, pitching, and rolling motions were observed. The influence of the hybrid suspension system has been associated with driver seat acceleration as compared with the passive model, also simulation model and experimental model.

About five years ago, the riding comfort was set after conducting various types of tuning tests. These required considerable man powers and large scale improvement was impossible in wide frequency range. To get large scale improvement and reduce these man powers, an optimum design was needed in the initial stage of development. First, the simulation model of whole vehicle was made to analyze the frequency responce on cab floor and human body when an excited force was added to the front tire. Next, 25 parameters which effected the riding comfort were allocated to L36(211 × 313) type orthogonal array and then 72 simulation analyses were conducted. Of the 25 parameters, 8 were finally selected to be the most effective, after comparing the results with many factorial effect charts. It was confirmed that the test results were well matched with the simulation and all acceleration levels at resonance points fell down over 50%.

In 1934 M. Olley suggested, in his paper “Independent Wheel Suspensions - Its Whys and Wherefores”, that a rear axle stiffness slightly higher than proportional to rear axle load would give improved comfort. By the introduction of body fixed coordinates a velocity dependent damping factor occurs in the equations of motions. That factor has been named inertial damping. The linear study of the parameter space shows that a stiff front suspension will cause a separation of the damping of the body eigenfrequenciesat increased vehicle velocity. On the other hand, and this was the conclusion of Olley, a soft front suspension will cause a separation of the frequencies at increased velocity. As the system dampings and the natural frequencies in most cases vary with the velocity of the vehicle the stability margin should be checked. The theoretical results indicate that good ride forwards can cause bad ride during reverse driving.

The leaf spring suspension - still widely applied in commercial vehicles - does not offer an optimum with regard to suspension performance. Due to the possibility of the levelling adjustment, the careful cargo treatment and the better ride comfort, the air suspension is, therefore, more and more succeeding. To meet the requirements of higher performance of air suspensions in a cost favourable way and to to take full benefit of the potential of air suspensions, an electronically controlled air suspension system (ECAS) for trucks and buses has been developed and introduced into the market. The functions of the entire system, its components as well as the advantages of the ECAS are described in comparison to the conventionally controlled air suspension systems. Moreover, the system is extended to a semi-active suspension control, i. e. the integration of the damping control into the air suspension control. The result is a further improvement of the ride properties.

Glare from the headlights of following vehicles which is reflected in rearview mirrors can be a significant problem. Glare can cause driver discomfort, it can diminish the driver's ability to see, and it can cause driver fatigue, particularly during prolonged night-time driving common for many professional drivers. Conventional rearview mirrors, such as silvered and chromed mirrors, offer only one reflectivity level. Variable reflectance mirrors, such as those utilizing electrochromic and liquid crystal technology, are capable of multiple reflectance levels. With variable reflectance, the driver can select a high reflectivity level during daytime driving or when reversing into loading docks, and can select a reduced dimmer reflectance level when driving during glaring conditions. This paper briefly reviews the principal technologies available for variable reflectance mirrors and outlines their performance as glare-reducing mirrors.

This paper describes the results of experiments carried out for modifying the characteristics of leaf springs with a view to improving ride comfort in leaf spring suspension vehicles. In this study, the factors contributing to the hysteresis loop of leaf springs, especially to the inclination in the transition zone of the hysteresis loop, were analyzed experimentally. The results of analysis were used in designing leaf springs with smaller inclination in the transition zone, and then the tests were carried out with these leaf springs. It is known that the dynamic spring characteristics of leaf springs is mainly related to the gradient of the diagonal of load-deflection hysteresis loop, that is diagonal spring rate. The diagonal spring rate is inversely proportional to the amplitude, of the deflection approximately and consequently, at very small amplitude, it reaches to the maximum inclination in this transition zone.

Filtering the road unevenness, i.e. comfortable ride for passengers, and vibration and shock isolation for freight, is one of the main thrusts behind the development of active and semi-active suspensions. For control of these systems, a variety of different schemes, mainly from the linear stochastic control area, have been proposed by researchers: and 1/4-car active and semi-active suspension models are used to simulate these schemes. Besides the main input an exogenous input is also considered, namely a velocity disturbance originating from the road unevenness. In most of the literature in this area, this disturbance is considered as white noise, which it hardly is. This a-priori statistical description of the disturbances, is necessary for using stochastic control techniques. In this paper, a comparison of some of these control schemes is performed.

The Eaton® Fuller® EconoShift™ transmission is designed for high mileage fleets wanting fuel efficient operation and improvement in driver comfort combined with proven reliability. Starting with early development of concept vehicles and “voice of the customer” analysis--through QFD project management, simultaneous engineering, product specifications, FMECA and other design and development tools--to test plans and service diagnostics--the EconoShift transmission successfully meets the customers' expectations. These important design and development steps as well as the technical features of the product are discussed.

When truck tires have a deformation such as radial runout, flat spot, and abnormal wear as a result of panic braking, they affect vehicle vibration in the form of displacement input whose spectrum involves higher order terms of tire revolution. While a truck has vibration modes of frame bending as well as pitching and unsprung-mass viberation in the input frequency range, the tire displacement input induces vehicle vibration as a combination of these modes. Results of calculations and experiments of a 4x2 medium-duty truck are analyzed and an example of means for improving ride comfort is described in this paper.

Modern agricultural machines are very complex, requiring extensive monitoring of multiple operations at the same time as they travel over very rough terrain. Hence, the cabs must be designed to provide not only good visibility of all monitors and easy access to all controls, but operator comfort and safety as well. This includes climate control (temperature, humidity, dust, noise, etc.), vibration damping, easy access on to and off of the tractor, good visibility from the cab and no controls jutting out where they could constitute a hazard. Good cab design promotes efficiency, comfort and safety.