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Abstract When commercial vehicles drive in a mountainous area, the complex road condition and long slopes cause frequent acceleration and braking, which will use 25% more fuel. And the brake temperature rises rapidly due to continuous braking on the long-distance downslopes, which will make the brake drum fail with the brake temperature exceeding 308°C [1]. Meanwhile, the kinetic energy is wasted during the driving progress on the slopes when the vehicle rolls up and down. Our laboratory built a model that could calculate the distance from the top of the slope, where the driver could release the accelerator pedal. Thus, on the slope, the vehicle uses less fuel when it rolls up and less brakes when down. What we do in this article is use this model in a real vehicle and measure how well it works.

The main purpose of this research is to investigate the optimal design of pipeline diameter in an air brake system in order to reduce the response time for driving safety using DOE (Design of Experiment) method. To achieve this purpose, this paper presents the development and validation of a computer-aided analytical dynamic model of a pneumatic brake system in commercial vehicles. The brake system includes the subsystems for brake pedal, treadle valve, quick release valve, load sensing proportional valve and brake chamber, and the simulation models for individual components of the brake system are established within the multi-domain physical modeling software- AMESim based on the logic structure. An experimental test bench was set up by connecting each component with the nylon pipelines based on the actual layout of the 4×2 commercial vehicle air brake system.

A new approach for detecting problems with vehicle brakes by analyzing sounds emitted during braking events is proposed. Vehicle brakes emit acoustic energy as part of the braking process; the spectra of these sounds are highly dependent on the mechanical condition of the brake and can be used to detect problems. Acoustic theory indicates that as brake linings wear thinner the resonant frequency of the shoe or pad increases, potentially enabling the monitoring of lining wear through passive acoustic sensors. To test this approach, passive acoustic sensors were placed roadside at the exit of a transit bus facility for 9 months. The sensors collected almost 10,000 recordings of a fleet of 160 vehicles braking over a variety of conditions. Spectra of vehicles that had brake work performed during this period were analyzed to compare differences between new and worn friction linings.

Being a safety critical aggregate, every aspect of brake system is considered significant in vehicles operations. Along with optimum performance of brake system in terms of deceleration generation, brake pedal feel or brake feel is considered as one of the key elements while evaluating brake system of vehicles. There are many factors such as liner and drum condition, road surface, friction between linkages which impress the pedal feel. Out of these, in this paper we will be discussing the factors which influence the brake pedal feel in relation to the driver comfort and confidence building. Under optimum braking condition, brake operation must be completed with pedal effort not very less or not very high, brake pedal feel must be firm throughout the operation, in such a way that it will not create fatigue and at the same time it will give enough confidence to the driver while operating with acceptable travel.

In today’s automobile industry refined NVH performance is a key feature and of high importance governing occupant comfort and overall quality impression of vehicle. In this paper interior noise and vibration measurement is done on one of the light truck and few dominant low frequency noise booms were observed in operation range. Modal analysis was done for the cabin at virtual as well as experimental level and few modes were found close to these noise booms. Vibrations were measured across the cabin mounts and it was found that the isolation of front mounts is not effective at lower frequencies. Taking this as an input, the mount design was modified to shift the natural frequency and hence improve the isolation behavior at the lowest dominant frequency. This was followed by static and dynamic measurement of the mounts at test rig level to characterize the dynamic performance and stiffness conclusion.

In recent days, the usage of disc brake is increased acutely in commercial vehicle applications apart from the passenger vehicles. The main advantage of using disc brake is reducing the stopping distance, temperature and wear between the disc and pad. During the braking, kinetic energy of the vehicle is converted into thermal energy due to the friction between disc and pad. To maintain the temperature between the disc and pad is critical for the overall performance of the disc brake and safety of the vehicle. The process of vehicle braking is a dynamically thermal structure coupling problem which is complex in nature. In this study, temperature between the disc and pad is determined using Finite Element Analysis for two different pad configurations. As per recent vehicle norms by the government the axle load is increased by 20 % which requires increased braking force and will leads to high temperature in the disc pad interface.

Lift axle is essentially provided in commercial vehicles to increase the vehicle’s load-carrying capacity. The axle is lowered in the case of a high payload and the load is evenly distributed among the wheels both on fixed axles and the lift axle. This ability to lift the axle implies better maneuverability in turns, better fuel consumption, and less wear and tear on the tires and brake shoes. Also, it will reduce the damage to the road surfaces. This lowering and lifting of the lift axle are controlled by a series of valves together called the Lift Axle Control System (LACS). This LACS must consider the vehicle load condition, the ignition state, and gear state to decide if the axle must be lifted or lowered. This paper deals with the modeling and simulation of the LACS system at the vehicle level and optimize the design for the respective desired design solution.

Autonomous vehicle operation is dependent upon accurate position estimation and thus a major concern of implementing the autonomous navigation is obtaining robust and accurate data from sensors. This is especially true, in case of Inertial Measurement Unit (IMU) sensor data. The IMU consists of a 3-axis gyro, 3-axis accelerometer, and 3-axis magnetometer. The IMU provides vehicle orientation in 3D space in terms of yaw, roll and pitch. Out of which, yaw is a major parameter to control the ground vehicle’s lateral position during navigation. The accelerometer is responsible for attitude (roll-pitch) estimates and magnetometer is responsible for yaw estimates. However, the magnetometer is prone to environmental magnetic disturbances which induce errors in the measurement.

This SAE Recommended Practice establishes uniform test procedures and performance requirements for engine-off heating, ventilation, and air conditioning (HVAC) systems in order to achieve driver thermal comfort in both winter and summer rest periods. This specification will apply to heavy trucks with and without sleeper compartments, including but is not limited to Class 6, 7, and 8 powered vehicles.

This SAE Recommended Practice establishes uniform test procedures and performance requirements for engine-off heating, ventilation, and air conditioning (HVAC) systems in order to achieve driver thermal comfort in both winter and summer rest periods. This specification will apply to heavy trucks with and without sleeper compartments, including but is not limited to Class 6, 7, and 8 powered vehicles.

This SAE Recommended Practice establishes a uniform test procedure for determining performance levels of operator enclosure panel type air filters on off-road, self-propelled work machines used in construction, general-purpose industrial, agriculture, and forestry as defined in SAE J1116 and equipped with an operator enclosure with a powered fresh air system.

This SAE Standard describes methods for evaluating the performance of the systems detection device, the minimum detection areas behind the machine, the visual and audible information presented to the operator and ground personnel, and the systems fault detection requirements. Also included are operator system function tests and maintenance procedures.

This SAE Standard applies to machines as defined in Appendix A. Some of these machines can travel on-highway, but function primarily off-highway.

This SAE Standard applies to machines as defined in Appendix A. Some of these machines can travel on-highway, but function primarily off-highway.

This SAE Recommended Practice provides instructions and test procedures for measuring air consumption of air braked vehicles equipped with Antilock Brake Systems (ABS) used on highways.

This SAE Recommended Practice provides instructions and test procedures for measuring air consumption of air braked vehicles equipped with Antilock Brake Systems (ABS) used on highways.

This document establishes standard graphical symbols and color conventions for use in either still (static) or animated graphics used for communicating service information. This document’s purpose is to communicate conventions for using those symbols and colors to accurately and consistently communicate intended information via graphics-based documentation. These practices are intended for use in service procedures, assembly instructions, training materials, and similar applications when trying to minimize the amount of human natural language text used within the document. The still and animated graphical conventions referenced should support effective communication via paper and “traditional” electronic media. The conventions can also extend to documenting via additional electronic delivery paradigms such as Augmented Reality (AR).

This document establishes standard graphical symbols and color conventions for use in either still (static) or animated graphics used for communicating service information. This document’s purpose is to communicate conventions for using those symbols and colors to accurately and consistently communicate intended information via graphics-based documentation. These practices are intended for use in service procedures, assembly instructions, training materials, and similar applications when trying to minimize the amount of human natural language text used within the document. The still and animated graphical conventions referenced should support effective communication via paper and “traditional” electronic media. The conventions can also extend to documenting via additional electronic delivery paradigms such as augmented reality (AR).

Safety of the operators in any equipment can be achieved by both passive and active systems. Passive safety system includes Seat belt, air bag, bumper, and other structural components which protects the operator from injuries during accidents. On the other hand, Active safety systems like Braking, Steering, Collision avoidance system, operator fatigue monitoring systems, etc., minimize and eliminate the accidents among which the Brake system is primarily used to control and stop the equipment. Considering the field operating conditions of motor grader, it is very essential to provide fool proof braking system to control and stop the equipment. In order to obtain maximum productivity the equipment speed is kept substantially high. Brake systems are operated using Air, Hydraulics, etc., among which the Air brake system offers simple and easy serviceability over hydraulic system.

Abstract In this article, a new road load simulation technology is presented for commercial vehicle driveline. In order to assess the performance of vehicle driveline, the chassis dynamometer system is introduced on the basis of the traditional vehicle driveline test bench, which improves the accuracy of the simulation system without the need of complex modeling of commercial vehicle tire dynamics. The vertical load of the vehicle is emulated by the hydraulic loading mechanism, and the influence of the vertical load on commercial vehicle driveline is emulated when the vehicle passes the bumpy road. The evaluate control method of commercial vehicle acceleration inertia based on wheel rotational speed and vehicle dynamics model is designed.