Development of Diagnostic Algorithms for an Air Brake System: Theory and Implementation

2011 ◽  
Author(s):  
Sandeep Dhar ◽  
Swaroop Darbha ◽  
K. R. Rajagopal
Keyword(s):  
Motor Vehicle ◽  
Brake System ◽  
Chamber Pressure ◽  
Vehicle Safety ◽  
Brake Pad ◽  
Safety Standard ◽  
Brake Pressure ◽  
Brake Application ◽  
Air Brakes ◽  
Air Brake System

In this paper, we consider the problem of designing an algorithm for estimating the stroke of a pushrod of the air brake system. The stroke of pushrod directly relates to the braking force available at the wheels and also affects the response time. The longer the stroke, the volume available for expansion is larger and correspondingly, the response is slower. The stroke depends on the clearance between the brake pad and the drum, which can vary due to variety of factors such as thermal expansion of drum and mechanical wear. Typical safety inspections of air brakes include the measurement of the stroke of the pushrod of each brake chamber. Regulations on trucks such Federal Motor Vehicle Safety Standard (FMVSS) 121 require the inspection to be carried out at 90 psi supply pressure and at full brake application. The evolution of the brake pressure depends on the stroke of the pushrod and the area of the treadle valve, which is controlled by the driver. The treadle valve meters compressed air from the supply reservoir to the brake chamber. The proposed scheme requires the measurement of pressure and a model for predicting the evolution of brake chamber pressure in response to full application of the brake (brake pedal is fully depressed). We experimentally corroborate the effectiveness of the proposed algorithm.

Relating the Strength Capabilities of Children to the Design of School Bus Emergency Roof Hatches

2016 ◽  
Vol 60 (1) ◽  
pp. 1652-1655
Author(s):  
Yousif Abulhassan ◽  
Jerry Davis ◽  
Richard Sesek ◽  
Sean Gallagher ◽  
Mark Schall ◽  
...  
Keyword(s):  
Motor Vehicle ◽  
First Grade ◽  
Emergency Evacuation ◽  
Vehicle Safety ◽  
School Bus ◽  
Safety Standard ◽  
Optimal Force ◽  
Motor Vehicle Safety ◽  
Minimum Force ◽  
Overall Effectiveness

School bus emergency exits are regulated by the Federal Motor Vehicle Safety Standard (FMVSS) No. 217 which does not consider the strength capabilities of children. The purpose of this study was to evaluate the strength capabilities of children to determine the optimal force specifications required to operate school bus emergency escape roof hatches. Force exertions were measured using test apparatuses built to replicate the operating mechanisms of the emergency escape roof hatch on a school bus. Force and torque exertions of 33 subjects in the first grade were measured using an emergency escape roof hatch knob. Forty two percent of the measured maximum push force exertions on the emergency escape hatch knob were less than the 89 newton minimum force requirement specified by FMVSS No. 217. Matching the operational requirements of emergency exits to the strength capabilities of children can help improve the overall effectiveness of the emergency evacuation system.

scholarly journals KEGAGALAN FUNGSI PENGEREMAN BIS DAN TRUK AKIBAT RUSAKNYA KOMPONEN RAKITAN KAMPAS REM

ROTASI ◽  
2015 ◽  
Vol 17 (1) ◽  
pp. 19
Author(s):  
Dwi Basuki Wibowo ◽  
Ismoyo Haryanto
Keyword(s):  
Public Transportation ◽  
Motor Vehicle ◽  
Vehicle Safety ◽  
Heavy Duty ◽  
Safety Standard ◽  
Brake Shoe ◽  
Heavy Duty Vehicle ◽  
Motor Vehicle Safety

Federal Motor Vehicle Safety Standard (FMVSS) mengklasifikasikan kendaraan bis dan truk (trailer dan container) sebagai heavy duty vehicle dimana rem, kopling, dan ban adalah komponen-komponen yang harus diperiksa secara rutin karena berkaitan dengan keamanan dan umur pemakaiannya yang relatif pendek. Sebagai komponen utama material gesek kampas rem memang harus bagus dan harus lolos serangkaian test sebagaimana diatur dalam berbagai standard yaitu SNI 09-0143-1987, ASTM G0115-04, ASTM D3359-02. Tetapi menurut The American Public Transportation Association (APTA BTS-SS-RP-003-07), kinerja sistim pengereman bis dan truk tidak semata-mata ditentukan oleh kualitas material kampas rem saja tetapi juga oleh kondisi brake shoe dan prosedur pemasangan (rebuild) kampas pada brake shoe. Dari hasil survey banyak pengusaha transportasi bis di Indonesia yang mengabaikan prosedur rebuild kampas rem yang telah distandarkan oleh APTA BTS-SS-RP-003-07 tersebut. Akibatnya kampas rem cepat aus, rem terkunci, dan yang paling parah adalah rem blong (rem tidak berfungsi). Fokus utama penelitian ini adalah mengkaji kemungkinan kerusakan brake shoe assembly (komponen rakitan kampas rem) saat pengereman yang berpotensi menyebabkan terjadinya kegagalan fungsi pengereman pada bis/truk.

scholarly journals A Control-Oriented Linear Parameter-Varying Model of a Commercial Vehicle Air Brake System

2020 ◽  
Vol 10 (13) ◽  
pp. 4589 ◽  
Author(s):  
Dawei Hu ◽  
Gangyan Li ◽  
Guoming Zhu ◽  
Zihao Liu ◽  
Yingxu Wang
Keyword(s):  
Nonlinear Model ◽  
Commercial Vehicle ◽  
Force Balance ◽  
Brake System ◽  
Chamber Pressure ◽  
System Response ◽  
Linear Parameter ◽  
Linear Parameter Varying ◽  
Parameter Varying ◽  
Air Brake System

This paper presents a control-oriented LPV (Linear Parameter-Varying) model for commercial vehicle air brake systems, where a pneumatic valve actuator is used to control the brake chamber pressure. To improve the brake system response time and reduce the vehicle stopping distance, the traditional treadle valves used in the air brake system are replaced by electro-pneumatic valves. Also, to develop the model-based brake control strategy, a nonlinear mathematical model is developed based on Newton’s second law, fluid dynamics of the orifice, force balance of spool, and solenoid dynamic characteristics. The brake chamber dynamics is also considered during the charging and discharging processes. The developed nonlinear model is calibrated based on both valve actuator geometry and test bench experimental results. It is proposed to model the nonlinear system in the LPV form so that gain-scheduling controllers can be developed. To obtain the LPV model, system identification is conducted using the calibrated nonlinear model to obtain a set of linearized models under different brake chamber pressure levels, and the resulting identified linear models are assembled to form the LPV model with brake chamber pressure as the varying parameters. A linear infinite-horizon continuous-time LQR (Linear Quadratic Regulator) controller was designed for the braking system based on the developed LPV model with the fixed parameter to demonstrate the effectiveness of the developed LPV model.

An Evaluation of Production Vehicle Roof Strength

2004 ◽  
Author(s):  
Jack Bish ◽  
Carl E. Nash ◽  
Allan Paskin ◽  
Terence Honikman ◽  
Donald Friedman
Keyword(s):  
Pitch Angle ◽  
Motor Vehicle ◽  
Side Impact ◽  
Vehicle Safety ◽  
Safety Standard ◽  
Current Standard ◽  
Original Proposal ◽  
Current Production ◽  
Motor Vehicle Safety ◽  
Roof Strength

Automobile roof strength is regulated by Federal Motor Vehicle Safety Standard, FMVSS, 216, promulgated in 1971 as a temporary alternative to the dolly rollover test of FMVSS 208. The originally proposed test focused the load on the A-Pillar/Roof Rail/Header intersection and required both sides of the roof to be tested sequentially mimicking the contact sequence in a multiple rollover. The current standard is a less stringent part of the original proposal, which tests the vehicle at a shallower pitch angle with a larger platen and only stresses the first or leading side impact of the vehicle roof. A new fixture has been built that closely duplicates the originally proposed test (NHSB 1971), but with more realistic load application angles that are different on the near and far side of a vehicle during a roll. Tests performed to date illustrate the weakness of current production vehicle roofs.

Compensation Control Network and Test of Bus Air Brake System in Under-Pressure State

2014 ◽  
Vol 711 ◽  
pp. 342-346 ◽  
Author(s):  
Zhi Shen Wang ◽  
Gang Yan Li
Keyword(s):  
Brake System ◽  
Control Network ◽  
Communication Interface ◽  
Compensation Control ◽  
System Pressure ◽  
Brake Pressure ◽  
Air Brake System ◽  
Pressure Compensation ◽  
Status Data ◽  
Pressure State

The paper aims at pressure compensation control of bus air brake system in under-pressure state, based on SAE J1939 protocol, using CAN bus technology, the nodes such as vehicle status data acquisition node, brake system pressure information collection node, brake pressure compensation controller node, brake actuator system node, test and diagnostic node were defined, hardware and software of communication interface were designed, under-pressure compensation control network of bus air brake system was built and test, the test results show reliability, stability, real-time of the network meet the requirements of brake control.

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