GB2468764A

GB2468764A - Vehicle lighting systems

Info

Publication number: GB2468764A
Application number: GB1004214A
Authority: GB
Inventors: Trevor Mark Coaker Davey; Hugh Robert Loxton
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-03-17
Filing date: 2010-03-15
Publication date: 2010-09-22
Also published as: GB201004214D0

Abstract

A remotely controlled lighting system, which includes means for the generation of coded radio/infrared signals to allow a parent vehicle/body to control battery-powered removable warning or operational lighting associated with the use of that vehicle/body and its attachments.

Description

VEHICLE LIGHTING SYSTEMS

Field of the Invention

This invention relates to vehicle lighting systems.

The invention is of particular, but not exclusive, application to lighting systems for agricultural and other large vehicles.

When a farmer is driving a tractor along a road and is towing a large implement such as a plough or a tedder, the implement can obscure the tractor brake lights or indicator lights and accidents can thus occur when a tractor driver slows down or turns to the right or to the left, either because a following driver fails to see the tractor brake lights or indicator lights, or does not appreciate that the tractor is towing a large implement.

When, of course, the tractor is towing a trailer or the like, he will attach a light board to the trailer or the like so that the signals made by the tractor are replicated on the light board. The designs of ploughs and other large implements can, however, be such that there is no convenient location for mounting a light board and, even if the driver finds somewhere to mount to light board, he will have to remove the light board before he can start using the plough or other large implement otherwise the light board will be damaged.

It is accordingly an object of the present invention to provide an improved vehicle lighting system, particularly one which enables the problems outlined above to be overcome.

Summary of the Invention

According to a first aspect of the present invention there is provided a remotely controlled lighting system which includes means for the generation of coded radio/infrared signals to allow a parent vehicle/body to control battery-powered removable warning or operational lighting associated with the use of that vehicle/body and its attachments.

The parent vehicle/body may be, for example, a mobile crane or a gantry crane.

According to a second aspect of the present invention there is provided a vehicle lighting system which includes one or more lights, means for mounting the light or lights on apparatus towed by the vehicle, transmitting means mounted on the vehicle and receiving means on the light or lights for controlling operation of the light or lights in response to operation of the vehicle's brakes and indicators.

There are preferably a plurality of lights operated by rechargeable batteries and means are preferably provided for recharging the batteries when the lights are placed in, for example, the cab of the vehicle. Thus, as applied to an agricultural tractor, sockets are preferably provided in the cab of the tractor so that, except when the lights are mounted on the apparatus, the lights can be stored in the tractor cab in such manner that they are ready for re-use as and when required.

The lights are preferably "brake" lights and "indicator" lights, the brake" lights being red lights and the "indicator" lights being flashing orange lights. The lights may alternatively be number plate lights, fog lights, flashing beacons or reversing lights.

The transmitting means is preferably linked to the vehicle controls so that, when the vehicle brakes are applied, a signal is transmitted to cause the red "brake" lights to be activated whereas, when the vehicle indicator switch is operated, a signal is transmitted to cause the appropriate orange "indicator" light to be operated.

The lights may also include continuous red "rear" lights and some or all of the lights may be combined together as part of a unitary assembly which includes a lens or lenses of the appropriate colour(s).

S The transmitter is preferably a short range radio or infra red transmitter arranged to transmit coded signals to the receiving means of the lights.

Brief Description of the Drawings

Figure 1 shows the circuit diagram for the transmitter, and Figure 2 shows the circuit diagram for the receiver.

Description of the Preferred Embodiment

A lighting system for use by a tractor driver when towing, for example, a plough comprises six lights, i.e. two red "brake" lights, two red "rear" lights and two orange "indicator" lights. The lights include housings within which rechargeable batteries are disposed, together with, in the case of the "brake" lights and the "indicator" lights, receivers for receiving control signals from transmitting means on the tractor.

The housings for the orange "indicator" lights will be mounted on the rear of the plough, one adjacent each side thereof, and the mounting arrangements are such that the housings can be fitted securely in place without the requirement for fixing tools, for example, by the use of locking clips and/or magnets which engage parts of the frame of the plough. The mounting arrangements are also such that the housings can be removed from the frame of the plough without the requirement for tools.

The housings for the red "brake" lights and the red "rear" lights will also be mounted on the rear of the tractor, inwardly of the "indicator" lights, in such manner that they can be fitted on, and removed from, the frame of the plough without the requirement for tools.

The housings for the lights are so shaped that, for transport and storage purposes, they can be mounted in a rack or the like within the tractor cab in such manner that recharging of the rechargeable batteries is effected. Thus, when the tractor driver wishes to mount the lights on the plough, or other implement being towed by the tractor, the batteries are recharged ready for use of the "rear", "brake" and "indicator" lights.

Short-range transmitting means is provided on or in the tractor cab and is linked to the tractor control systems so as to generate signals in response to operation of the tractor brakes and indicators, i.e. in unison with the tractor's own brake lights and indicator lights. The transmitting means may be a radio or infra red transmitter which generates coded signals which are received by the receiving means of the lights to cause operation of the lights.

Before, therefore, a tractor is driven along a road at dusk or in the evening towing a plough, the driver will take the lights from the tractor cab and will mount them in the appropriate positions on the plough. After the tractor has been driven into a field or yard and the lights are no longer required, they will be removed from the plough and replaced in the tractor cab. The lights will thus be in a secure location and the batteries will again be recharged. The possibility of the lights being damaged while ploughing is being carried out is thus avoided.

Although the invention has been described above with reference to the mounting of lights on a plough being towed by an agricultural tractor, the invention is applicable to vehicle lighting systems generally as referred to above.

The Transmitter Module:-The purpose of this module is to accept the incoming voltages from the signal and running lights of the "command" vehicle e.g. a car, van, truck, etc. and convert these into an encoded signal which is then transmitted via an RF link for conversion back into the corresponding light signals in the receiver unit.

Methodology: -As the standard seven pin trailer light socket fitted to most UK vehicles has no permanent supply, this unit is powered by a very novel means. When any of the vehicle's signal lights is activated, 12V from the battery is applied to one or more of the pins in the connector. All five signal and running lights are "Diode OR'ed" together to a common 12V rail so that a 12V output on any can create an internal supply. This 12V supply is fed through a regulator to reduce the voltage to a level appropriate for the "super cap" reservoir.

The output from the "super cap" is switched by an FET, the purpose of which is to shut off the low voltage supply, and thus retain enough power for "instant start", e.g. rapid repeated application of the brakes. A regulator and capacitor provide this function and ensure that the transmitter and encoder are shut off after approximately 3 minutes in order to conserve power.

When active, the voltage supplied from the "super cap" is fed into a proprietary DD-DC converter which outputs around 9VDC and runs at about 60% efficiency. This 9V is then fed into a 5V regulator to supply the encoder chip and the transmitter module.

Each of the possible signals to be encoded is fed through a diode I resistor / zener diode network to reduce the command vehicle 12V output to a level acceptable to the TIL logic system used. The pattern these signals form on 5 bits of the inputs of one 8 bit port are read by the software contained in the encoder chip and converted to a data stream which is fed serially at an optimized rate (4800 Baud) to the transmitter module. The data encoding system used takes into account the noisy environment in which this system will be required to operate, but contains no handshaking due to the fact that as long as any one input is active, the encoded data is transmitted repeatedly. Upon a condition change e.g. a brake light turning off, this change is transmitted during the whole time the "super cap" is switched on.

This provides added safety as the possibility that a light may become "stuck on" is all but negated.

A simple modification (for use with the Euro 13 pin sockets) to the circuit adds the REVERSE lights to the transmitter. These are already implemented in the universal receiver modules.

The Receiver Module:-The purpose of this module is to accept the incoming signal via an encoded, uniquely addressed Radio Frequency link from the transmitter and thence to decode this signal back into the same pattern as the command vehicle signal lights.

Methodology: -The RE receiver converts the modulated RE signal into an encoded serial data stream at some 4800 baud rate (This rate was selected as it was found that, in tests, it gave the optimum balance between system response and errors introduced by limits in the method of encoding, transmission and ambient noise levels) and asynchronously sends the data to the decoder chip.

The serial data is then fed asynchronously into the decoder chip wherein it is converted into a bit pattern to mimic the "command vehicle's" signal light pattern and output on one of its *port whose individual bits drive the light modules which are constructed using high efficiency Light Emitting Diodes so as to maximize battery and life and maximize the MTBF (Mean Time Between Failures) of the illumination system.

Every receiver or light module is designed to be identical and it is only in the " learn" or "pair" mode that it is decided (in one embodiment) whether the unit is to be "left" or "right" handed. This is achieved as follows; The receiver decoder chip contains a mode which it enters ONLY when the unit is powered up with the "Learn" button depressed. The receiver then looks for the first transmitter address identifier that it can find. Upon receipt of this address identifier, it then waits for a predetermined length of time during which it looks for more iterations of the SAME address identifier in any received RF data stream. When the decoder is certain that enough iterations have been received to confirm that the transmitter whose encoded data it has been processing is the one with which it is meant to be paired, it locks the address identifier in non-volatile memory and, thereafter, will ONLY respond to data streams which contain that unique 24 bit address identifier code. Should the unit fail to pair with a transmitter within a certain time period it will hold a solid brake light signal for two seconds and then automatically restart the pairing process.

Once pairing has been achieved as described above, the decoder chip will flash the brake light three times then proceed to the "handed" routine.

In order to set the unit to left or right handed and to initiate the transmission of the address identifier from the transmitter module, a change in the pattern of the command vehicle's signal lights is required (remember the transmitter only sends a signal when a voltage is present on any of the light drive pins on the seven pin socket). In one embodiment, to make the unit left handed, the command vehicles LEFT turn signal is set to active.

This data is decoded in the receiver module and a flag defining the unit as left handed is set and stored in non-volatile memory. To make the unit right handed, the same process is followed, but this time with the vehicles RIGHT hand turn signal active. When the unit is in service, the left and right signals in a receiver module drive the same LED array, except that a left handed unit suppresses the "right drive" bit of its output port and vice versa for a right handed module. In the second embodiment, a simple toggle switch selects which output drives the LED array. In both cases it is up to the user to ensure that they do not end up with two similarly handed units.

The receiver module has two preferred embodiments, in both cases the unit supports:- * Turn Signal (Indicator) * Fog Lamps * Running (Side) Lights (with additional drive for vehicle ID plate illumination) * Brake Lights * Reversing Lights (with connector to drive a warning sounder) Although not all functions may be used due to limitations of the transmitter, (seven pin UK trailer sockets do NOT have a reverse light drive pin as the seven pin socket was developed before most vehicles had this feature) all vehicle signal lights are decoded in the receiver. In order to maintain compatibility with the "Eurol3" version of the transmitter, the seven pin version still encodes this as a "virtual" pin in its data stream but is it is set to an "OFF" CO fl d iti on.

The brake lights and running lights share the same LED. A dimming resistor is used when the array is in sidelight mode.

However, when a "brake" signal is decoded, a lower value resistor is switched in parallel, thus allowing more current to flow and thus the array's intensity is increased.

The fog light array is driven at all times at the same high brightness level as the brake light array, but is physically separated by the reversing light array, thus allowing optical discrimination between the two from a distance.

The indicator system is where the two embodiments differ. In one the choice of "Left" or Right" is selected by a toggle switch mounted on the top of the unit's housing. In the other embodiment the decoder algorithm automatically selects the correct output to drive the LED array, based upon the initial "learning" done when the unit is first paired with its transmitter.

Finally the receiver unit is powered by a rechargeable battery system. Due to the possibility of extremes of negative temperature which may occur in cold weather caused by both ambient and wind chill and thus cause battery failure the battery system is heated. This is achieved by placing the power resistors used to dim the running lights, and those also used to limit the current drawn through the brake and fog light arrays under the battery pack. Warm air from these resistors rises and gently warms the battery pack, keeping it from reaching critical failure temperatures in external temperatures as low as -20 degree Celsius. This heating effect would not cause adverse operation in the positive temperature range unless ambient exceeded an unlikely 80 degrees Celsius! The battery is monitored by the decoder chip as long as the unit is turned on and, if below a critical level at ANY point during this on period, a case mounted LED is turned on and a flag SET in non-volatile memory, which latches this Battery Low" LED and triggers an audible signal to indicate the need for charging. ONLY switching the unit on with a fully charged battery will clear this flag Wand cause the "Battery Low" LED to extinguish and the sounder to silence. A partially charged battery will still flag as "charging required".

In order to ensure a realistic power on battery test, ALL LED arrays are turned on when the unit is switched on (except where the unit has not been paired) to heavily load the battery for 20 seconds. Again as above if the monitored battery voltage drops below the critical threshold the charge light latches and the internal buzzer sounds.

The battery system is designed to give a MINIMUM operation time of ten (10) hours under full load. It is, however, more likely that this will be up to 50% more based on average driving conditions. For safety's sake, where it is suspected that these conditions may be exceeded, it would be advisable, at the start of the journey, for a user to have two pairs of receiver modules, both paired to the same transmitter, and to swap them over half way through.

In one embodiment there is no method of monitoring the battery condition remotely. However, in a third embodiment, all units are capable of inter-module communication allowing full system monitoring, including LED array current (to identify failed LED's within a module). This third embodiment requires only the receiver module to be modified with the inclusion of a TRANSCEIVER module and a modified decoder chip, as there is no need for the transmitter module to have receive capability due to there being no need for handshaking.

In all embodiments, there is a "tell tale" mounted on the command vehicle's dashboard which gives the driver visual confirmation of system operation. However, in the third embodiment with inter-module communication this tell tale is driven by the output from the light decoder modules, rather than the transmitter module, and incorporates an in-vehicle module low battery indicator (LED and sounder) and true and correct indication of repeated (trailer) light operation.

Claims

Claims:- 1. A remotely controlled lighting system which includes means for the generation of coded radio/infrared signals to allow a parent vehicle/body to control battery-powered removable warning or operational lighting associated with the use of that vehicle/body and its attachments.
2. A vehicle lighting system which includes one or more lights, means for mounting the light or lights on apparatus towed by the vehicle, transmitting means mounted on the vehicle and receiving means on the light or lights for controlling operation of the light or lights in response to operation of the vehicle's brakes and indicators.
3. A vehicle lighting system as claimed in Claim 2, which includes a plurality of lights operated by rechargeable batteries and in which means are provided for recharging the batteries.
4. A vehicle lighting system as claimed in Claim 3, as applied to an agricultural tractor, in which sockets are provided in the cab of the tractor so that, except when the lights are mounted on the apparatus, the lights can be stored in the tractor cab in such manner that they are ready for re-use as and when required.
5. A vehicle lighting system as claimed in Claim 2, 3 or 4, in which the lights are "brake" lights and "indicator" lights, the "brake" iights being red lights and the "indicator" lights being flashing orange lights.
6. A vehicle lighting system as claimed in Claim 5, in which the transmitting means is linked to the vehicle controls so that, when the vehicle brakes are applied, a signal is transmitted to cause the red "brake" lights to be activated whereas, when the vehicle indicator switch is operated, a signal is transmitted to cause the appropriate orange "indicator" light to be operated.
7. A vehicle lighting system as claimed in any one of Claims 2 to 6, in which the transmitter is a short range radio or infra red transmitter arranged to transmit coded signals to the receiving means of the lights.
8. A remotely controlled lighting system substantially as hereinbefore described with reference to and as shown in the accompanying drawings.