Abstract:
The LED motorcycle lighting system is designed to help improve visibility of riders during night and day riding. The system includes an array of LED lights disposed in a housing adapted for mounting on a weight-balanced bracket. The weight-balanced bracket is adapted for mounting on a motorcycle&#39;s caliper mount to secure the LED lamp to the vehicle. Using two weight-balanced mounting brackets, a first LED lamp is mounted on the left front of the motorcycle, while a second LED lamp is mounted on the right front of the motorcycle. The system uses pulse width modulated current drivers fed by an adjustable PWM signal to allow brightness adjustment of the lights by the user to suit a particular riding situation. A handlebar-mounted potentiometer adapted for adjusting the PWM signal provides easy access to the user for brightness control of the lights.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to motorcycle roadway lights, and more specifically to an LED motorcycle lighting system that provides a caliper-mounted roadway light having an LED brightness controller. 
         [0003]    2. Description of the Related Art 
         [0004]    Lighting systems for motorcycles are important to provide illumination of driving surfaces in dark or low visibility conditions and to improve the visibility of motorcycles to other vehicles and pedestrians. While motorcycles have typically been provided with a main headlight for illuminating the road ahead of the motorcycle, headlights are generally mounted high on the handlebars, and thus illumination of the road immediately in front of the motorcycle is degraded. To improve the illumination of the road, many motorcycle operators choose to add accessory lights on lower portions of the motorcycle to supplement the illumination provided by the main headlight. 
         [0005]    In addition to providing improved illumination of the road, such accessory lighting may also provide benefits in terms of improved safety. While headlights may be visible to drivers of other vehicles on the road, the fact that motorcycles generally have a single headlight, or closely spaced pairs of headlights, makes it difficult for other drivers to adequately determine the distance and rate of speed of a motorcycle moving toward them. The frequency of accidents involving motorcycles may be decreased when the motorcycles are provided with additional lights, which are lower than the headlight and spaced on opposite sides of the motorcycle to provide additional visual references for determining the distance and rate of speed of an approaching motorcycle. This is especially true when the motorcycle driver is given the opportunity to adjust the brightness of the accessory lighting to suit a particular riding situation. 
         [0006]    Accordingly, there is a need for a brightness adjustable accessory riding light for motorcycles that can be easily mounted to existing structure of the motorcycle and which does not require extensive modification of the motorcycle. 
         [0007]    Thus, an LED motorcycle lighting system solving the aforementioned problems is desired. 
       SUMMARY OF THE INVENTION 
       [0008]    The LED motorcycle lighting system is designed to help improve the visibility of motorcycle riders during night and day riding. The system includes an array of LED lights disposed in a housing adapted for mounting on a weight-balanced bracket. The weight-balanced bracket is adapted for mounting on a motorcycle&#39;s caliper mount to secure the LED lamp to the vehicle. Using two weight-balanced mounting brackets, a first LED lamp is mounted on the left front of the motorcycle, while a second LED lamp is mounted on the right front of the motorcycle. The system uses pulse width modulated current drivers fed by an adjustable PWM signal to allow brightness adjustment of the lights by the user to suit a particular riding situation. A handlebar-mounted potentiometer adapted for adjusting the PWM signal provides easy access to the user for brightness control of the lights. 
         [0009]    These and other features of the present invention will become readily apparent upon further review of the following specification and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a block diagram of a motorcycle LED lighting system according to the present invention 
           [0011]      FIG. 2  is an environmental perspective view of a LED array mounted to a motorcycle according to the present invention. 
           [0012]      FIG. 3  is an environmental perspective view of a LED array control mounted to a motorcycle handlebar according to the present invention. 
           [0013]      FIG. 4  is a block diagram of the electrical connection of a LED lighting system according to the present invention. 
           [0014]      FIG. 5  is a circuit diagram showing the microprocessor of a LED lighting system according to the present invention. 
           [0015]      FIG. 6  is a front environmental perspective view of a LED array mounted to a motorcycle according to the present invention. 
           [0016]      FIG. 7  is an exploded perspective view of a LED array assembly being mounted to a motorcycle caliper mount according to the present invention. 
       
    
    
       [0017]    Similar reference characters denote corresponding features consistently throughout the attached drawings. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0018]    As shown in  FIGS. 1 and 6 , the LED motorcycle lighting system  10  is comprised of a riding light  32  that includes a Light emitting Diode (LED) array  62  which produces a bandwidth of light which facilitates visibility of the rider to other vehicles and visibility of the road to the rider. The LED array riding lamp  32  incorporates a pulse width modulation (PWM) “dimming” system to allow use in all environmental lighting situations. 
         [0019]    While the LED array riding lamp  32  can be mounted in various locations on a motorcycle, a preferred mounting position is on a caliper mount CM of the front wheel proximate the brake caliper. Preferably the LED array riding lamp  32  is mounting as far away as possible from the original headlights on the motorcycle. This configuration gives the on-coming motorist a better chance to judge direction, speed and distance of the motorcycle. Referring to  FIGS. 1 ,  4 ,  5 A- 5 B, a preferred embodiment is shown in which two LED array riding lamps  32  are connected to one of current drivers  400  and  402  controlled by microprocessor  502 , the current drivers  400  and  402  being connected via wiring harness  27  to the factory bulb socket connection  39  of a motorcycle&#39;s electrical system. If the motorcycle uses CANBUS technology, the wiring harness  27  may be a. CANBUS relay harness. The relay harness may be comprised of silver plated Teflon insulated wiring. The wiring harness cable is preferably silicone lubricated internally to help prevent vibration damage to the wiring of harness  27 . The lamp housing  33  supports the LED array  62 , and a bracket  40  is configured to mount the housing  33  to a caliper mount CM proximate a front brake caliper  700  on a motorcycle. Accordingly, both lamps  32  may easily be installed on the motorcycle by removing a pre-existing brake caliper fastener, positioning the riding light adjacent the brake caliper fastener hole proximate the caliper mount CM, and installing standoff bushings  60 , then fastening the assembly with a substitute fastener  63  having a longer shank than the original brake caliper fastener had. 
         [0020]    The PWM is generated by the microprocessor  502  which preferably can change the duty cycle of the voltage driving the lamps  32  at a very quick rate, e.g., approximately 240 Hz. The exemplary microprocessor  502  is an ATMEL TINY45V, which has approximately 8 KB of memory and includes flash memory for storing a list of values representing dimming curves for LED array riding lamps  32  in the present invention. Advantageously, the human eye interpolates the “high” pulses with the “off” time and processes this as a dimming function. 
         [0021]    A control potentiometer  26  connected to an analog to digital (A/D) converter in the microprocessor  502  digitally encodes the PWM signal to each of the constant current drivers  400  and  402  connected to the LED lamps  32 . Constant current driver  400  is a 1000 mA constant current device, while constant current driver  402  is a 2800 mA constant current device. Micro Controller  502  utilizes two of its PWM outputs, which are buffered to simultaneously control the two LED drivers  400  and  402 . By adjusting the potentiometer  26 , the motorcyclist can brighten or dim the lamps as desired. As shown in  FIG. 3 , the potentiometer  26  and its rear housing  25  are mounted on handlebar HB of the motorcycle for ease of use by the cyclist. 
         [0022]    Moreover via the two LED drivers  400  and  402 , the inventive apparatus can control a low power version of LED array riding lamps  32  that provides an accent light to make the rider conspicuous and a high power version of LED array riding lamps  32  that more fully illuminates the driving environment. Both outputs are functional and can be adjusted via control potentiometer  26 . 
         [0023]    Additionally, the riding light system  10  may have a “Hi-Low” relay  15  connected to a user operated switch that could be coupled to or in close proximity with potentiometer  26  which has a HI selection and a LO selection. A 30-ampere fuse  20  protects the wiring portion of the system  10  proximate lead of battery B. A 5-ampere fuse  35  protects wiring of the system  10  “downstream” from the battery B and relay  15 . Placing the switch in the HI position selects the motorcycle&#39;s HIGH beam, interrupts the PWM signal from microprocessor  502  and applies 100% duty cycle to the LED current drivers  400 ,  402  so that the LED riding lamps  32  are at their brightest setting. When the LOW beam is selected, the relay  15  engages the PWM signal driven by microprocessor  502  and the lights  32  again respond to the set level of potentiometer  26 . Thus, the motorcyclist can quickly adjust the light output when approaching oncoming traffic. 
         [0024]    As shown in  FIGS. 4 ,  5 A- 5 B, the LED driver is comprised of a current regulated dc to dc switching regulator  506  which keeps voltage to the system in a predetermined nominal range irrespective of load demanded by the LED array riding lamps  32 . Header  504  provides an interface for programming the microcontroller  502  and writing dimmer response data into flash memory of microcontroller  502 . 
         [0025]    The drivers  400 ,  402  can support LED array  62  which may be comprised of at least one, and is preferably three series connected white LED&#39;s. The drivers  400 ,  402  operate under a nominal 12V motorcycle or vehicle electrical supply. Exemplary LED driver  402  has a PWM input to enable dimming of the LED array  62 . Dimming is implemented by varying the duty cycle of the constant current source provided by exemplary LED driver  402 . Control potentiometer  26  connected to an analog to digital converter in the microprocessor  502  digitally encodes the PWM signal to each of the constant current drivers  400  and  402  connected to the LED lamps  32 . 
         [0026]    Rear portion  25  of the control potentiometer  26  is preferably mounted in close proximity to the processor  502 . The control potentiometer  26  may be of any type including log, linear, semi log etc. The potentiometer  26  is disposed in the control circuitry in a voltage divider configuration that provides a variable analog voltage to an analog to digital converter in the microcontroller  502  which then, based on comparison of the digital value to values stored in flash memory of processor  502  outputs a resultant digital PWM duty cycle. 
         [0027]    The tabular values are read by processes running in processor  502 , which then maps the position of potentiometer  26  as required to provide a dimming curve that is appropriate for a motorcycle/vehicle auxiliary light. An added feature is that the maximum brightness setting, i.e., maximum average current setting, of potentiometer  26  (PWM output) can be arbitrarily set within flash memory of processor  502  to provide a safe operating temperature of the LED array riding lamps  32 . Additional thermal protection circuitry is provided by the use of a small thermal probe  553  (shown in  FIG. 5A ) attached to a circuit board upon which the LED array  62  is mounted, the probe monitoring LED surface temperature. At a predetermined temperature, the probe  553  sends a calibrated resistance to the PWM circuit. At elevated temperatures, LED&#39;s can have diminished life spans. This calibrated circuit can intervene and roll back the duty cycle until temperature drops below the predetermined level. This feature helps prolong the life of the LED&#39;s  62  under elevated environmental temperatures. 
         [0028]    The controller  502  is programmed with a set of instructions which cause the controller  502  to accept a command from the user via potentiometer  26  in which the user rotates the potentiometer  26  to its high limit and then to its low limit quickly low/high/low/high a specified number of times within the initial few seconds of power application to toggle/cycle the control device  502  to chose a specific potentiometer-pwm mapping table in memory, as there may be either a single table or a plurality of tables to chose from. This enables the user to select from a variety of current output tables, e.g., a conservative maximum output table may be selected or a full power output table may be selected. 
         [0029]    As shown below in the tables, an exemplary embodiment of the present invention includes two tables for a high powered version of LED array  62  and two tables for a 1000 ma version of LED array  62 . Additionally, third and fourth tables are provided for a 2800 ma version of LED array  62 . Preferably there are 64 dimming levels per table. It should be understood that each table may be independently custom tuned via data input through the programming header  504  for specific driver usage and for low or high modes. By clever programming of the tables, a daytime running light position can be implemented. That is to say, the lowest level in the table will dim, but not turn off the LED array riding lamps  32 . Exemplary dimmer tables representing ratio of x/240 or x/243) are illustrated in the tables below. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 (pwm_table_1000 mA (high)[64] PROGMEM) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 0 
                 8 
                 16 
                 24 
                 32 
                 40 
                 47 
                 54 
               
               
                 61 
                 68 
                 75 
                 82 
                 88 
                 94 
                 100 
                 106 
               
               
                 112 
                 118 
                 124 
                 130 
                 135 
                 140 
                 145 
                 155 
               
               
                 161 
                 165 
                 168 
                 171 
                 174 
                 177 
                 180 
                 183 
               
               
                 186 
                 189 
                 192 
                 195 
                 198 
                 200 
                 202 
                 204 
               
               
                 206 
                 208 
                 210 
                 212 
                 214 
                 216 
                 218 
                 220 
               
               
                 222 
                 224 
                 226 
                 228 
                 230 
                 231 
                 233 
                 235 
               
               
                 236 
                 237 
                 238 
                 239 
                 240 
                 241 
                 242 
                 243 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                 (pwm_table_1000 mA (low)[64] PROGMEM) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 72 
                 78 
                 83 
                 88 
                 93 
                 97 
                 102 
                 105 
               
               
                 110 
                 115 
                 120 
                 125 
                 130 
                 138 
                 122 
                 126 
               
               
                 130 
                 134 
                 138 
                 141 
                 145 
                 149 
                 153 
                 157 
               
               
                 161 
                 165 
                 168 
                 171 
                 174 
                 177 
                 180 
                 183 
               
               
                 186 
                 189 
                 192 
                 195 
                 198 
                 201 
                 204 
                 207 
               
               
                 210 
                 213 
                 216 
                 218 
                 220 
                 222 
                 223 
                 224 
               
               
                 225 
                 227 
                 229 
                 231 
                 232 
                 233 
                 234 
                 234 
               
               
                 236 
                 237 
                 238 
                 239 
                 240 
                 241 
                 242 
                 243 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 3 
               
               
                   
               
               
                 (pwm_table_2800 mA (high)[64] PROGMEM) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 0 
                 8 
                 16 
                 24 
                 32 
                 40 
                 47 
                 54 
               
               
                 61 
                 68 
                 75 
                 82 
                 88 
                 94 
                 100 
                 106 
               
               
                 112 
                 118 
                 124 
                 130 
                 135 
                 140 
                 145 
                 155 
               
               
                 161 
                 165 
                 168 
                 171 
                 174 
                 177 
                 180 
                 183 
               
               
                 186 
                 189 
                 192 
                 195 
                 198 
                 201 
                 204 
                 206 
               
               
                 208 
                 210 
                 212 
                 214 
                 216 
                 218 
                 220 
                 221 
               
               
                 223 
                 225 
                 226 
                 228 
                 229 
                 230 
                 231 
                 232 
               
               
                 233 
                 234 
                 235 
                 236 
                 237 
                 238 
                 239 
                 240 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 4 
               
               
                   
               
               
                 (pwm_table_2800 mA (low)[64] PROGMEM) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 56 
                 62 
                 67 
                 72 
                 77 
                 82 
                 88 
                 93 
               
               
                 98 
                 103 
                 108 
                 112 
                 116 
                 120 
                 124 
                 128 
               
               
                 132 
                 136 
                 140 
                 144 
                 148 
                 152 
                 156 
                 160 
               
               
                 164 
                 168 
                 171 
                 175 
                 178 
                 181 
                 184 
                 187 
               
               
                 190 
                 192 
                 194 
                 196 
                 198 
                 200 
                 202 
                 204 
               
               
                 206 
                 208 
                 210 
                 212 
                 214 
                 216 
                 218 
                 220 
               
               
                 222 
                 224 
                 226 
                 228 
                 229 
                 230 
                 231 
                 232 
               
               
                 233 
                 234 
                 235 
                 236 
                 237 
                 238 
                 239 
                 240 
               
               
                   
               
             
          
         
       
     
         [0030]    The tables in flash memory of processor  502  are “tunable” for specific needs and may provide either a linear or a non-linear mapping to actual duty cycle of the PWM signal delivered to the current drivers  400  and  402 . Since the human eye is more sensitive to small intensity changes when dim, the table is preferably tuned to ‘smooth’ the transitions between the discrete value steps in the table. 
         [0031]    To execute the aforementioned PWM brightness control for LED array riding lamps  32  of the present invention, it is contemplated that a computer product comprising a medium readable by processor  502 , has a set of instructions readable by processor  502  thereon, the set of instructions being executable by processor  502  when loaded into instruction memory of the processor  502 . For controlling brightness level of LED array riding lamps  32 , the aforementioned set of instructions running on processor  502  cause the processor  502  to read a digital number obtained by A/D conversion of analog voltage input to the A/D converter, the analog voltage being determined by setting of control potentiometer  26 , and to index into the active PWM table using the read digital number. 
         [0032]    The set of instructions further causes processor  502  to retrieve a table entry specified by the aforementioned PWM table indexing procedure. The processor  502  then uses the retrieved table entry value as a new parameter to adjust its PWM output thereby brightening or dimming the LED array riding lamps  32  (if the retrieved table entry value is lower than the previously retrieved value, the lamps  32  dim; if the retrieved table entry value is higher than the previously retrieved value, the lamps  32  brighten). It should be understood that the magnitude of the value difference between consecutive PWM table entries determines the perceived difference in brightness of lamps  32  as the processor  502  traverses the table entries responsive to a user adjusting potentiometer  26 , hence the PWM tables are custom tunable by the designer to achieve a desired brightness/dimming profile. 
         [0033]    As shown in  FIGS. 2 ,  6 , and  7 , the LED array riding lamp  32  has a housing  33  particularly suited for mounting on the front brake caliper mounting portion CM of a motorcycle. Components of housing  33  may be fitted together using a gasket system of O rings and threaded rings to give the internal elements a secure seal. Moreover, the main body of lamp  32  is preferably machined (under computer control for accuracy) from a solid billet of aluminum. The lamp  32  has cooling fins that are machined out of a grain oriented billet for maximum strength. A riding lamp mounting bracket  40  and the brake caliper  700  are positioned on opposing sides of the caliper mount CM and then fastened to the caliper mount CM. 
         [0034]    Caliper mount CM is a structural element of the motorcycle and includes at least one threaded through-bore  702  (see  FIG. 7 ) to which the brake caliper assembly  700  is mounted by threaded bolts  63  which engage washers  64 , riding light mounting bracket  40 , standoff bushings  60  and aligned holes in brake caliper assembly  700 . 
         [0035]    Standoff bushings  60  provide sufficient clearance in riding lamp mounting bracket  40  from the motorcycle&#39;s caliper mount CM such that mounting position of the LED array riding lamp  32 , avoids interference with other components of the motorcycle while positioning the LED array riding lamp  32  at a position which illuminates the road ahead of the motorcycle. 
         [0036]    It will be recognized that fasteners  63  are preferably longer than the original caliper fasteners to account for the aggregate thickness of washers  64 , LED array riding lamp mounting bracket  40 , and standoff bushings  60 . In this manner, LED array riding lamp  32  “piggy backs” on the brake caliper mounting bracket CM such that a lengthened version fastener  63  is used to fasten both the LED array riding lamp  32  and the brake caliper assembly  700  to the caliper mount CM on the motorcycle. 
         [0037]    The LED array riding lamp mounting bracket  40  is an isosceles triangular shaped member having caliper mount mounting holes  42  disposed on opposing ends of the long sided portion of the member. The aforementioned bracket fasteners  63  go through the caliper mount mounting holes  42 . An LED array riding lamp pivot mounting hole  43  is disposed proximate the apex of isosceles triangular shaped mounting bracket  40 . Interior portion of the member  40  has an arcuate lamp mounting aperture  44  symmetrically extending between the opposing iso-sides which allows a mounted LED array riding lamp  32  to be pivotally adjusted to a desired angle before tightly securing the lamp to the bracket  40  at aperture  44  with one of the lamp mounting threaded fasteners  72 . The other lamp mounting threaded fastener  72  is disposed through the pivot hole  43 . A second “balancing” aperture  45  is disposed below the lamp mounting aperture  44 . The balancing aperture  45  allows the bracket member  40  to be balanced at its centroid. 
         [0038]    An LED array riding lamp mounting boss  34  extends from the bottom of lamp housing  33 . Both lamp mounting threaded fasteners  72  are threaded into threaded bores  35  of LED array riding lamp mounting boss  34  to secure the lamp housing  33  to bracket  40 . A wiring cable  36  extends out of the rear portion of lamp housing  33  and is routed to the wiring harness  27  (shown in  FIG. 1 ). 
         [0039]    As most clearly shown in  FIG. 6 , the housing  33  of LED array riding lamp  32  secures a lens  65 , which protects the array of LEDs  62 . A reflector  664  surrounds each individual LED of the array  62 . 
         [0040]    It is to be understood that the present invention is not limited to the embodiment described above, but encompasses any and all embodiments within the scope of the following claims.