Presentation 2000/10/17
Safety Control Systems for Heavy Duty Vehicles
Schroder-Berg Jorg,
PDF Download Page PDF download Page Link
Abstract(in Japanese) (See Japanese page)
Abstract(in English) The Air Brake systems for commercial veheicles are undergoing a continuous development and improvement. New technologies like disk brakes and electronic brake control will increasingly be introduced. Compared to current state-of-the-art brake systems including ABS and ASR the systems offer the potential to reduce the stopping distance, to improve the brake force distribution and braking stability as well as the brake compatibility of vehecle combinations. Reduced stress for the driver and comprehensive monitorring of the brake system are further safety enhancements. Pure electrical brake control could still find some acceptance but there will be partial or mixed concepts initially. These will still have pneumatic control of some functions. A major share of the overall transport business is performed on roads by commercial vehicles. There are continuously increasing demands, due to higher traffic density, competition, increase of payload, environmental demands and driver workload. All these are taken into account in the continuous development of heavy duty vehicles to ensure their safety, economy and acceptance. Also the braking systems of these vehicles are constantly undergoing a continued improvement. Milestones of that was, for example, the introduction of antilock braking systems in heavy duty trucks. Both development. driven by WABCO and DC, found their first application in Germany and from there a rapid propagation in Europe and Japan, supported by the corresponding amendments in the legislation. An adaption of the concepts and a trend for harmonization of regulations in overseas markets are also evident. Meanwhile the next generation of brake systems the Electronical controlled brake systems are already in serial production. ANTI-LOCK BRAKE SYSTEMS The task of antilock system is prevent a wheel from locking. The antilock system uses wheel speed information to recognize locking tendency at one more wheels. With this information it decides to decrease, to hold or to increase the corresponding brake cylinder pressure. Vehicle stability is endangered in case of an active antilock function on road surfaces with extremely different coefficients of friction between the left and the right side. To avoid this problem the brake pressures on the front axle are controlled in such a way that the pressure difference between the front wheels is limited(modified individual control MIR). The permissible pressure difference between the front axle wheels depends on different inputs like vehicle speed, duration of brake application, etc. The rear axle is controlled individually. This means that both sides on the rear axle are pressurized corresponding to their tendencies to lock. ASR FUNCTION CONTROL Similar to the ABS function control the ASR Function detects wheel spinning of the driven axle. In this case the coefficient of friction between tire and road is too low and leads to an unstable behaviour. Lateral force at the driving axle breaks down and the tracter looses traction and possibly stability. To avoid this situation the ASR function reduces engine power. In addition the drive axle is pressurized.
Keyword(in Japanese) (See Japanese page)
Keyword(in English)
Paper # SSS2000-20
Date of Issue

Conference Information
Committee SSS
Conference Date 2000/10/17(1days)
Place (in Japanese) (See Japanese page)
Place (in English)
Topics (in Japanese) (See Japanese page)
Topics (in English)
Vice Chair

Paper Information
Registration To Safety (SSS)
Language ENG
Title (in Japanese) (See Japanese page)
Sub Title (in Japanese) (See Japanese page)
Title (in English) Safety Control Systems for Heavy Duty Vehicles
Sub Title (in English)
1st Author's Name Schroder-Berg Jorg
1st Author's Affiliation WABCO JAPAN()
Date 2000/10/17
Paper # SSS2000-20
Volume (vol) vol.100
Number (no) 390
Page pp.pp.-
#Pages 7
Date of Issue