The Ideal Vehicle Turn Signal System Configuration
While INTELLITURN is a huge technological leap forward in motor vehicle turn signal control, other areas of existing technological advancements are natural partners to combine with INTELLITURN to create a turn signal system that make all mechanical turn signals look, feel and behave like they are from the stone age.
Here are some design concepts outlined that would constitute the ideal system:
Wheel Speed Sensors: Vehicles built with anti-lock braking systems have wheel speed sensors that are highly engineered to withstand the brutal environment at the hub of the wheel to deliver a reliable, accurate signal. The very signals used for ABS can also be used for INTELLITURN. However, all that is required for turn signal information is from just two of the four sensors, one at each wheel. It would be most advantageous to utilize left rear and right rear signals for the primary turn signal information. This conveniently leaves the remaining two sensors to serve as backup in the event of a primary wheel speed sensor failure. Incidentally, in the event of an ABS sensor failure, the "ABS" warning light would come on at the instrument cluster, alerting the driver to service the system. The turn signal function, however would seamlessly detect the failure, thereby utilizing the alternate sensor pairs, and return to primary function when the ABS wheel speed sensor is serviced. The turn signal system would never miss a beat.
Sensing On Rear Wheels: The rear wheels (left & right) would be the first choice of the primary turn signal sensors for several reasons. These signal pairs, as processed by INTELLITURN, would trace the yaw of the vehicle better than the front wheels, since the rear wheels are always in alignment with the front to rear axis of the vehicle. Secondly, in a front drive vehicle, these are the non-driven wheels, and would therefore not slip upon hard acceleration, thereby reducing the chance of INTELLITURN to have to go into an error correcting mode. Now while an error correcting mode will regain a high degree of accuracy when the wheels stop slipping, the precision is somewhat reduced from ideal. The rear wheels are also constantly in line with the turning radius point, and would contribute to a more accurate turn signal system.
INTELLITURN Computer: While a stand-alone computer for turn signal function would work just fine, it makes the most sense to incorporate the function control for turn signals into the ABS computer or in the body computer. All four wheel speed sensor signals are incorporated into these computers already. The added input/outputs required would be a driver's stalk switch input (low power signal level), plus the lamp drive signals output (left turn and right turn, both high power). The added computing duty taken on by the ABS computer is insignificant in comparison to the requirements of the ABS system, so it would not be over burdened. Also, if the turn signals are tied into the CAN system, then additional vehicle information can be used to process turn signal control.
"Extreme Braking" Alert: While this may not necessarily fall in the category of "ideal", it is a function worth mentioning because it may add considerably to vehicle safety and is free to implement with INTELLITURN: In the event that the ABS detects an impending skid of the wheels, not only could the computer impose control over the skidding wheel, but it could additionally energize both the left and right turn signals simultaneously, effectively activating a 4-way flasher mode during the time of the ABS intervention, and then shut off the flashing upon shut off of the ABS intervention mode. What this accomplishes is to automatically alert the surrounding drivers of the "extreme braking condition" of the vehicle. This may go a long way towards alerting a following driver to be on-guard and quite possibly serve to prevent a rear end collision in slippery conditions. This mode is totally automatic, without any special intervention from the diver, and is simply a mater of programming if the turn signal function is in fact incorporated into the ABS computer. All of the parts and wiring is in place to add this feature. Again, the vehicle manufacturer would make the determination if this is a desirable feature.
Solid State Lamp Drivers / LED Lighting: Solid state lamp drivers that can be incorporated into the computer are ideal for taking a computer signal and driving lamps. These devices have become very efficient in recent years and are therefore becoming more the main stream as "high side drivers" for lighting. Couple this with Light Emitting Diodes (LED) that are far more energy efficient than traditional incandescent bulbs. Additionally, LED's require no color filtering, as they are available in motor vehicle-compliant Amber color or Red color as direct output. LED's have a host of other advantages that are making them a very attractive choice. Service life, smaller packaging, response time, just to name a few. The down side of LED's is the added cost as compared to incandescent, however, the prices of LED's continues to fall as the technology matures.
Totally Silent Turn Signal: This may be a tough change for today's driver to experience, but a silent turn signal is not only technically possible, but would enhance the noise / vibration / harshness level of the vehicle. Particularly for a luxury vehicle, or any upscale vehicle, this can be a huge leap forward. With INTELLITURN managing the turn signal function precisely as a tracking response to the driver's every action, there is no need for noise as an alert to the driver from the flasher relay. The multiple flaws of today's mechanical turn signals virtually require a noise to call attention to itself to be heard by the driver and all passengers. When designing the vehicle, manufacturers must determine how loud the "tick-tock" of a turn signal should be and this becomes the fixed sound level. Even then, it may not be heard if the windows are down or the stereo is up. Conversely, if you are sitting at a light with the turn signal on, the windows up and the stereo off, that sustained noise can be torturously loud after just a minute or two. There is no good compromise on designed-in turn signal noise level, so the best is none at all. However, if a manufacturer does decide that the driving public is just not ready for a silent turn signal, then a noise making device can easily be added. Some vehicles even have a built-in chime that comes on after driving a while with the turn signal on as a warning and a display of "Turn Signal On". This is a noble attempt at compensating for a flawed turn signal system by instructing the driver that the turn signal system needs tending to. Conversely, INTELLITURN actually manages the system quietly and would simply turn off the turn signal without fanfare, distraction, or driver intervention upon determination of a turn signal that is erroneous.
Heads-up display combined with all INTELLITURN-equipped vehicles: Heads-up displays are nothing new in automotive, having been around for more than 15 years. If a turn signal is made to be silent and indeed the driver would need a sensory assurance that the turn signal is on (or off), a simple heads-up display is a ideal method of assuring the driver of turn signal status, right in the field of view through the windshield. This does not have to be a fancy, aerospace designed or elaborate configuration. Just basic, green colored LED's properly positioned, shrouded and aligned to display at the driver. Proper design would dictate that the display would be fixed position, and not have to be adjusted to the height of the driver, but would work in a single configuration for drivers of all seating heights. Remember, the Heads-up display is off if the turn signals are off. But when they are on, it is far easier, as a driver to tune out a visual indicator when desired than to tune out an audible indicator. In other words, a heads-up display turn signal indicator is a better method than a "tick-tock" sound. It is the preferred method to use with INELLITURN and makes for a superior driving experience.
Elimination of the "Turn Signal On" alert warning: Many GM and Ford vehicles have an alert that comes on after about a mile with the turn signal on that beeps and presents a display that warns: "TURN SIGNAL ON". While this is a great attempt to prevent the driver from embarrassment or displaying an erroneous turn signal, the fact is that it is shown that the driver is somewhat startled by this warning. In some cases, a driver may confuse the warning with what might look like a command: Drivers may think: "what 'signal' am I supposed to turn on???!!!". Why in the world can't your $50,000 luxury car just simply take care of this instead of bothering the driver?!?! And also, one mile with an erroneous turn signal stuck on is like an eternity!! With INTELLITURN, it is taken care of: The intelligent turn signal system turns it off long before one mile of travel because it knows that what should have been a communicated intent to execute a turn has become an erroneous turn signal. No embarrassment. No fanfare. No warning beeps. No warning displays. No interruptions. INTELLITURN just takes care of itself. The "TURN SIGNAL ON" warnings become totally unnecessary.
Turn Signal Lever Ergonomics: This is where the driver interface and an ergonomically engineered switch can really shine. Since the switch is just a momentary switch and not coupled into a mechanical trip method, the tactile feel, movement and smoothness of the switch can be highly optimized to achieve a drastic improvement to the driving experience. Remember, a turn signal is used very frequently when driving (or at least it should be!). The cancel button on the lever is a bit of a change from what the driving public is used to, but if you actually go through the mental steps of manually canceling a mechanical turn signal, it usually results in a certain degree of fumbling, fine touch & finesse plus possibly taking your eyes off the road just to turn it off. With INTELLITURN, cancel is just that, "cancel". That means any and all turn signal functions. The button is always in the same place to the driver when the button is accessed, unlike the mechanical lever.
Versatile Turn Signal Lever Mounting: This "ideal" is the ideal as determined by the vehicle designers. The turn signal switch lever can be mounted literally anywhere, because it does not require a mechanical interface to the steering column. It can therefore be mounted on the steering column, or it could be mounted on the dash. Those locations make the most sense, because the lever should always be presented to the driver in the traditional left-of-the-steering-wheel position horizontally. But a manufacturer may determine that it may be an overall advantage to mount the lever one place over another. Mounting on the dash may have advantages in wiring, or styling. But the key is that the manufacturer now has options. Options can usually result in cost savings or other benefits. A dash mounted turn signal lever may fit with the uniqueness of the Intelligent turn signal system of INTELLITURN and differentiate that this is a turn signal system "like you've never seen before". Wherever the switch placement, the space required of the switch is going to be much smaller and the crowded steering column can now be made smaller. Incidentally, the switch wiring is now only two small gauge signal wires instead of 6, or 8 large gauge wires running up the steering column.
Steering Wheel Turn Signal Controls: Now this is really cool. With all of the controls that are currently on the steering wheel on various vehicles, many functions, such as HVAC and audio would be considered secondary driving functions as compared with items like the horn, or cruise control. But adding full function turn signal buttons on the left and the right sides of the steering wheel within easy touch control of the driver's reach makes for a real driver's car feature. This is not a substitute for the lever and in fact the turn signal lever would still be present and fully functional. The driver would simply touch the right button with the right thumb for the automatic right turn signal function, and hold the button with the thumb for a lane change. As you can imagine, this incredible feature quickly becomes the most frequently used control on the steering wheel and will make a driver wish it was on all the vehicles he/she drives. It is a feature that until INTELLITURN came along, was impossible to incorporate. You might be concerned about the turn signal controls being on the steering wheel when a driver unfamiliar with the steering wheel control feature gets in to drive. Not to worry!!! The traditional turn signal lever is still there as every driver expects it to be and functions like a traditional turn signal stalk. If this unfamiliar driver never uses the steering wheel controls, it is no problem whatsoever. This feature could be added for only the cost of the switches and is electrically a parallel input to the lever. This feature is high content, value added, and will become one of the features that a customer will brag about on his or her new vehicle.
Lane Departure Warning System Enhancement / Blind Spot Detection System Enhancement: These new systems both have a relationship with the vehicle turn signals. In the case of Lane Departure Warning (LDW), the system "reads" the road with a camera, and alerts the driver when the vehicle is drifting out of its lane. The system is momentarily disabled when the turn signal is activated. Lane Departure Warning could prove to be a great advancement to preventing accidents, but realize that it is a system that is directly dependent on the operation of the turn signals, and hence the accuracy of the turn signals. In order to have an intelligent Lane Departure Warning system, you must first have an intelligent turn signal system! The current turn signal mechanism is rudimentary and thus a very weak link in the proper function of a Lane Departure Warning system and the determination of the enable/disable status of the system. An erroneous turn signal left on for miles and miles on the highway will keep the LDW alert disabled and is therefore no help to the driver to warn of a lane departure. Only INTELLITURN, with its intelligent and accurate operation can fully optimize the potential of the Lane Departure Warning system. The blind spot detection systems would also would benefit from an accurate and intelligent turn signal system.
Fine Tuned for Perfection in Operation: Once the hardware is in place, the Engineers, Mathematicians, and Programmers can refine the on-road operation of the INTELLITURN algorithm to cover every driving / turning situation, resulting in the near perfect turn signal. The system is even programmed to compensate for differences in tire diameter as in when a tire is low, or a spare tire is in use. The system can adapt to a driver's particular turn signal usage habits. Artificial intelligence, or fuzzy logic can be utilized to achieve an even more intelligent system.
Other Ideal Concepts: A lamp malfunction could be detected through current sensing techniques within the computer. In the event of a malfunction, alerting methods can be utilized, such as flashing at a faster than normal rate, alerting the driver of the malfunction. Of course, a trailer tow accommodating wiring can be used to allow for the added system load of trailer lighting, sustaining the near perfect function of INTELLITURN. Other concepts are possible, such as a sequential turn signal (remember the Ford Thunderbird and the Mercury Cougar from the 60's?). With computer control of the turn signals and flash mode, sequential turn signals would be quite a nostalgic novelty that is easy to implement and without compromise to reliability.
©2008 RLP Engineering