In an automobile headlight, a 'meeting' beam (dip beam) is provided in addition to the driving beam (high beam) so as to reduce the dazzle for those approaching head-on to the vehicle.
The Auto Dipping Device for a head light is intended to automatically change the Headlight Circuit to either driving beam or dip beam given a particular set of road conditions, without the intervention of the driver. The present practice is to operate the dip switch manually.
The function of the headlight is to illuminate the road ahead of the automobile so as to reveal objects ahead from a safe distance; at the same time it should cause minimum discomfort and glare for drivers coming from the opposite side.
Manual dipping is not being done satisfactorily in India due to a variety of reasons, which includes sheer physical strain involved in operation of the dipper switch hundreds of times every night. (The total for a single night will be 1000 if we consider 8 hours of traveling and one encounter every one-minute and could exceed this number if one travels on roads with dense traffic). The other reason includes a general tendency of paying more attention to steering control at the cost of dipping during a critical vehicle meeting situation especially in the case of heavy loaded vehicles. More reasons are the physiological and psychological state of a driver, which is influenced by a variety of factors like working hours, economic issues and social factors etc. Another major cause is 'ego problem', which makes each one wait till the other person initiates dipping, which may not happen.
A frequent cause of accidents at nights is the glare caused by oncoming vehicles which momentarily blinds the driver's vision. It takes three to eight seconds for a person with good eyesight to recover from the glare and during this time the vehicle will have covered a long distance in utter darkness and it will be sheer luck if it escapes an accident.
The observations of the study group on road safety (Constituted by Government of India vide Resolution No.19 (14) 68, June 3, 1969) regarding the conditions of our national highways are: “The Indian roads are all essentially very narrow, tortuous in their alignment and suffer from many inadequacies, vis-à-vis the present day motor traffic which has registered a phenomenal increase during the post-Independence period. The other conditions of the roads like poor shoulders, narrow culverts and bridges, sharp and numerous curves and steep gradients which limit the sight distance, numerous low level causeways and submersible bridges are perennial hazards. All the above tell on the nerves of the driver, causing fatigue and leading to errors and misjudgment while driving”.
All the above indicate the importance of dipping of headlights in a country like India, so as to avoid the problem of glare which impairs the visibility which is vital for safe driving in a meeting situation during the night. This leads to the conclusion that an Auto Dipping Device can go a long way towards safety enhancement. WHAT IS AN AUTO DIPPER:
An Auto Dipper is a device capable of changing over the circuit of head light without intervention of the driver given a particular set of objective road conditions. Its primary aim is to reduce the dazzle for the observer approaching ahead of the vehicle while ensuring that the user will not be put to inconvenience. THE FUNCTIONAL REQUIREMENTS ON A DARK ROAD:
The basic function of an auto dipper is to maintain the head lamps in either driving beam or in meeting beam automatically depending on the opposing traffic.
AUTOMATIC DRIVING BEAM:
It has to bring into operation the driving beam if there is no oncoming vehicle. Necessarily this means the auto dipper must be immune to the signals from; street lamps, moonlight, road reflectance, solar radiation during the late dusk and early dawn. AUTOMATIC DIP BEAM:
It has to bring into...