STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

BACKGROUND OF THE INVENTION

The present invention relates to systems and methods for illumination control and distribution during a vehicle bank, such as when vehicle banks in order to take a curve or to turn, and more specifically to illumination control and distribution systems and methods that control and maintain a pattern of light generally horizontal during the vehicle bank.

For example,FIG. 1shows a motorcycle40traveling generally straight in a lane on a road42. As can be seen, motorcycle headlights have a primarily horizontally shaped light beam pattern44that is shaped according to requirements to illuminate the road42ahead without disruptively shining on oncoming traffic, and to provide sufficient illumination for the drivers line of sight area46. Unfortunately, the light beam pattern44suits illumination requirements when the motorcycle is traveling generally straight forward, but not when the motorcycle is banking.

When a vehicle such as the motorcycle40makes a turn, the motorcycle typically goes through some degree of bank angle, i.e., the motorcycle banks as the motorcycle is making a turn or traveling through a curve. Referring toFIG. 2, unfortunately, the headlight used in most motorcycles is secured to the motorcycle frame in a fixed position, which causes the horizontally shaped light beam pattern44cast by the motorcycle headlight to correspondingly tilt and bank as the motorcycle is banked on a curved road48. The banking of the headlight along with the motorcycle40causes the amount of light distributed by the motorcycle headlight to shift in an inward and downward direction, which is away from the actual direction of travel of the motorcycle, and away from the focus of the motorcycle driver's eyes and line of sight area46. This is particularly concerning for motorcycle drivers during cornering at night. With the amount of light distributed by the headlight light beam focused more in an inwardly direction, the driver's illuminated field of view generally forward of the direction of travel is reduced.

Attempts have been made to address the shortcomings of standard headlights that work well when the motorcycle is traveling straight ahead, but not when the motorcycle is banking. Systems have been suggested that include a velocity sensor along with several gyroscopes to detect the roll rate and the yaw rate of the motorcycle. Based on extensive calculations using the motion data from the gyroscopes and the velocity sensor, a mechanical system rotates or adjusts the rotational orientation about the optical axis of the headlight in a direction opposite to the bank angle of the motorcycle. Other systems mechanically move a mirror to adjust the direction of illumination coming from a fixed light source. Each of these systems requires complex computations, which require complex electronics, and they also require sophisticated mechanical systems to provide movement of the illumination from the light source. The mechanical systems add complexity and cost to both the headlight and the overall vehicle cost.

Some steerable headlights have been developed that address problems related to mechanically rotating headlights for automobiles. For instance, it is known to provide a one or two dimensional array of LEDs where the LEDs generate separate adjacent light fields and where different horizontal subsets of the LEDs may be illuminated to generate light patterns at different locations in front of the automobile. Although this type of arrangement may provide adjustable horizontal illumination for an automobile, it inadequately addresses the effect when a vehicle, such as a motorcycle, is banking. Merely providing additional illumination to the left or to the right fails to illuminate the portion of the curved road ahead of a motorcycle driver. The horizontal row of LEDs and associated horizontally shaped light beam pattern is still rotated off of horizontal and would tilt and bank during the vehicle bank (seeFIGS. 1 and 2).

What is needed are systems and methods that accurately calculate a bank angle, and based upon the bank angle, alter a distribution of illumination to more naturally illuminate more of the driver's field of view.

BRIEF SUMMARY OF THE INVENTION

It has been recognized that an angle of a vehicle can be accurately calculated using axis data, and based on the calculated angle, vehicle illumination optics can be controlled to maintain a pattern of illumination from an illumination source to be generally horizontal. For example, a bank angle of a vehicle can be accurately calculated using roll axis data, and based on the calculated bank angle, the illumination optics can be controlled, or the pitch rate data can be used to provide an improved illumination pattern when the vehicle is pitching either up or down due to a hill in the road, for example. In some embodiments, roll axis data and/or motion sensor offset can be incorporated into the bank angle calculation. In some embodiments, when yaw axis data equals zero, the calculated bank angle can be zeroed. The improved pattern of distributed illumination from the illumination source illuminates a more natural field of view for the vehicle driver during a bank. In some embodiments, the vehicle illumination source can include a primary illumination group and a plurality of side illumination groups.

In accordance with an embodiment of the invention, an apparatus is provided for calculating a bank angle value of a banking vehicle. The apparatus comprises an inertial measurement unit, the inertial measurement unit including a processor and at least one motion sensor operatively coupled to the processor. The processor is programmed to sample yaw rate data at a predetermined rate, the yaw rate data provided by the at least one motion sensor; compare the yaw rate data to a predefined minimum yaw rate and a predefined maximum yaw rate, and when the yaw rate data is between the predefined minimum yaw rate and the predefined maximum yaw rate, set a bank angle value to zero; and when the yaw rate data is not between the predefined minimum yaw rate and the predefined maximum yaw rate, calculate the bank angle value.

In accordance with an additional embodiment of the invention, an apparatus is provided for controlling a horizontal distribution of illumination from a vehicle when the vehicle is banking, the vehicle including a headlamp to distribute the horizontal distribution of illumination. The apparatus comprises an inertial measurement unit, the inertial measurement unit including a processor and a motion sensor operatively coupled to the processor, the motion sensor to be coupled to the banking vehicle. The processor is programmed to sample yaw rate data at a predetermined rate, the yaw rate data provided by the motion sensor coupled to the banking vehicle; receive a motion sensor offset value; compare the yaw rate data to a predefined minimum yaw rate and a predefined maximum yaw rate, and when the yaw rate data is between the predefined minimum yaw rate and the predefined maximum yaw rate, determine if the motion sensor offset value is between a predefined minimum offset and a predefined maximum offset; when the yaw rate data is not between the predefined minimum yaw rate and the predefined maximum yaw rate, or when the motion sensor offset value is not between the predefined minimum offset and the predefined maximum offset, determine a roll data sum, the roll data sum equal to a roll rate data value minus the motion sensor offset value, and then calculate the bank angle value; and when the motion sensor offset value is between the predefined minimum offset and the predefined maximum offset, set the bank angle value to zero.

In accordance with a further embodiment of the invention, a vehicle headlamp for providing a horizontal distribution of illumination for a vehicle when the vehicle is banking is provided. The headlamp comprises a headlamp housing. An inertial measurement unit is positioned within the housing, the inertial measurement unit including a processor and at least one motion sensor operatively coupled to the processor. A primary illumination group and a plurality of side illumination groups are positioned with the headlamp housing, the primary illumination group and the plurality of side illumination groups operatively coupled to a driver board, the driver board operatively coupled to the processor. The processor is programmed to sample yaw rate data provided by the at least one motion sensor; compare the yaw rate data to a predefined minimum yaw rate and a predefined maximum yaw rate, and when the yaw rate data is between the predefined minimum yaw rate and the predefined maximum yaw rate, set a bank angle value to zero; and when the yaw rate data is not between the predefined minimum yaw rate and the predefined maximum yaw rate, calculate a bank angle value and cause at least one of the plurality of side illumination groups to illuminate to provide the horizontal distribution of illumination for the vehicle when the vehicle is banking.

In accordance with yet a further embodiment, an apparatus for calculating a angle value of a vehicle is provided. The apparatus includes an inertial measurement unit, the inertial measurement unit including a processor and at least one motion sensor operatively coupled to the processor. The processor is programmed to sample motion data at a predetermined rate, the motion data provided by the at least one motion sensor; compare the motion data to a predefined minimum motion rate and a predefined maximum motion rate, and when the motion data is between the predefined minimum motion rate and the predefined maximum motion rate, set a vehicle angle value to zero; and when the motion data is not between the predefined minimum motion rate and the predefined maximum motion rate, calculate the vehicle angle value.

In accordance with yet a further embodiment, a headlight system for a vehicle includes a motion sensor configured to sample yaw rate data, a primary illumination source, a plurality of secondary illumination sources, and a processor configured to control an illumination pattern provided by the primary illumination source and the plurality of secondary illumination sources in response to a bank angle value output by a bank angle calculation. The bank angle calculation is configured to sample the yaw rate date from the motion sensor, and compare the yaw rate data to a predefined minimum yaw rate and a predefined maximum yaw rate. When the yaw rate data is between the predefined minimum yaw rate and the predefined maximum yaw rate, the bank angle value is set to zero. When the yaw rate data is not between the predefined minimum yaw rate and the predefined maximum yaw rate, the bank angle value is calculated.

In accordance with yet a further embodiment, a headlight system for a vehicle includes a motion sensor configured to sample yaw rate data, an illumination source including an array of illumination elements, and a processor configured to control an illumination pattern provided by the illumination source in response to a bank angle value output by a bank angle calculation. The bank angle calculation is configured to sample the yaw rate date from the motion sensor, and compare the yaw rate data to a predefined minimum yaw rate and a predefined maximum yaw rate. When the yaw rate data is between the predefined minimum yaw rate and the predefined maximum yaw rate, the bank angle value is set to zero. When the yaw rate data is not between the predefined minimum yaw rate and the predefined maximum yaw rate, the bank angle value is calculated.

In accordance with yet a further embodiment, a method for calculating a bank angle value and controlling a headlight on a vehicle includes sampling yaw rate data, determining if the yaw rate data is between a predefined minimum yaw rate and a predefined maximum yaw rate, upon determining that the yaw rate data is between the predefined minimum yaw rate and the predefined maximum yaw rate, setting the bank angle value to zero, upon determining that the yaw rate data is not between the predefined minimum yaw rate and the predefined maximum yaw rate, calculating the bank angle value, and controlling an illumination pattern provided by the headlight based on the bank angle value.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described. The following description and the annexed drawings set forth in detail certain illustrative aspects of the invention. However, these aspects are indicative of but a few of the various ways in which the principles of the invention can be employed. Other aspects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the drawings.

