THE PERFORMANCE OF TWO SELF-LEVELLING HEADLAMP SYSTEMS

THE EFFECTIVENESS OF A CORRECTLY AIMED HEADLAMP CAN BE LOST BY CHANGES IN THE ATTITUDE OF THE VEHICLE BODY. THESE ARE LARGELY THE RESULT OF ALTERATIONS IN THE STATIC LOAD CARRIED, BUT CAN ALSO COME FROM SUSTAINED ACCELERATION AND DECELERATION. THIS EFFECT CAN BE COUNTERED IN A RELATIVELY SIMPLE WAY BY AUTOMATICALLY ALTERING THE SETTING OF THE HEADLAMPS. THE PERFORMANCE OF TWO SELF-LEVELLING HEADLAMP SYSTEMS, ONE MECHANICAL AND ONE HYDRAULIC, WAS INVESTIGATED. BOTH BEHAVED WELL DURING STATIC LOADING, CORRECTING WELL FOR CHANGES IN REAR, CENTRAL AND FRONT LOADING. DYNAMIC TESTS WHICH VIBRATED THE FRONT AND REAR WHEEL PAIRS SEPARATELY UP TO A FREQUENCY OF 9 HZ SHOWED A TENDENCY FOR THE MECHANICAL SYSTEM TO RESONATE UNDER CERTAIN CONDITIONS, BUT DRIVER TESTS INDICATED THAT THIS WAS UNLIKELY TO OCCUR UNDER NORMAL DRIVING CONDITIONS. DRIVERS FOUND THE INDEPENDENT MOVEMENT OF THE HEADLAMPS MOST NOTICEABLE WITH THE MECHANICAL SYSTEM, PARTICULARLY ON ROUGH AND UNEVEN SURFACES. /AUTHOR/

• Corporate Authors:

  Transport and Road Research Laboratory (TRRL)

  Wokingham, Berkshire  United Kingdom 
• Authors:
  • YERRELL, J S
• Publication Date: 1971

Media Info

• Features: Figures;
• Pagination: 24 p.

Subject/Index Terms

• TRT Terms: Alignment; Automation; Headlamps; Leveling
• Old TRIS Terms: Aligning
• Subject Areas: Highways; Safety and Human Factors;

Filing Info

• Accession Number: 00221691
• Record Type: Publication
• Source Agency: Nat Safety Council Safety Res Info Serv
• Files: TRIS, ATRI
• Created Date: Jul 24 1972 12:00AM