The invention relates to wheel sensing arrangements, wheel sensors and wheel sensing methods.
Numerous wheel sensors are available for sensing the ambient temperature and/or pressures in the ambient pneumatic region of a tyre.
GB2236885 employs an optical sensor in the context of wheel sensing. However, the optical sensor for receiving radiation is located in this prior art document on a stationary part of an associated hub assembly. The component associated with the rim is only an emitter. The combination of infra-red emitter and a sensor operates between the rim of the wheel and the stationary portion of the hub assembly. The optical sensor only receives data once every revolution when the emitter and sensor are in line. The optical sensor neither points towards the inside surface of the tyre nor does it view the inside surface in order to be able to receive radiation radiated from the inside surface.
The following further prior art documents are acknowledged: GB2363463, U.S. Pat. No. 5,708,411, and U.S. Pat. No. 5,663,496.
One object of the invention is to provide a wheel sensor which allows not only the ambient temperature to be measured, but also the surface temperature and in particular, the internal surface temperature of the tyre.
Another object of the invention is to improve the facility to assess the tyre condition during a motor race.
A further object of the invention is to provide a wheel sensor which may be readily integrated with other sensor features such as ambient pressure, and the temperature at the rim.
It is an object of the invention to provide a system which allows data to be gathered which is more closely linked to the evolution of temperature at the tyre surface and which would be less influenced by the rim temperature which is influenced by the heat generated during the braking process.
A further object of the invention is to provide a system which may be readily fitted to a rim without requiring specific rim and/or tyre modifications.
A further object of the invention is to allow a plurality of areas to be assessed independently around the wheel.
In a first broad independent aspect, the invention provides a wheel sensing arrangement comprising a wheel with a pneumatic tyre and a rim, the tyre and the rim forming a pneumatic chamber, sensing means or a sensor located within said pneumatic chamber for sensing one or more conditions within said pneumatic tyre of a wheel and an attachment means or fastener configured to secure said sensing means or sensor to said wheel rim, wherein said sensor further comprises an optical sensor pointing towards and viewing the inside surface of said tyre for receiving radiation radiated from said inside surface; whereby temperature values may be derived representative of said tyre surface temperature.
This configuration is particularly advantageous because it allows the tyre pressure to be assessed from the inside of the tyre without any contact with the tyre itself. It also allows specific data to be generated, representative of the tyre surface temperature which may be then compared with the ambient tyre temperature and/or the temperature within the vicinity of the rim. It also lends itself to straightforward fitting into existing rims and/or tyres without any specific structural modification being necessary.
In a subsidiary aspect in accordance with the invention's first broad independent aspect, said optical sensor is an infrared sensor. This configuration is particularly advantageous because it allows the sensing to occur in extreme temperatures from, for example, −40° Celsius to 125° Celsius. It also allows for accurate assessments to take place in particular whilst the wheel is in motion.
In a further subsidiary aspect, said sensor is configured to view the inside surface of the tyre corresponding to a tread region, and the inside surface of the tyre corresponding to lateral regions of said tyre. This configuration is particularly advantageous because it allows both the inside surface and the lateral regions to be assessed simultaneously. It may therefore lend itself to identifying potential hot spots across this area.
In a further subsidiary aspect, said sensor is configured to separately view the inside surface of the tyre corresponding to a tread region, and the inside surface of the tyre corresponding to lateral regions of said tyre. This will allow the various portions of a tyre to be assessed separately in order to monitor the evolution of the measured temperature with a separate degree of refinement relative to a given area if necessary.
In a further subsidiary aspect, said sensor is configured to view a single view. This configuration is particularly advantageous because it minimises the amount of views monitored and assessed. It therefore allows the processing speed to be optimised whilst providing a significant advance over only monitoring ambient temperature.
In a further subsidiary aspect, said sensor is configured to view two separate views which overlap in a region corresponding to the inside surface of the tread region. This configuration is particularly advantageous because it allows in effect the field of view to be segmented into three distinct regions. It therefore allows a separate analysis of three regions whilst employing a sensor configured to view only two separate views.
In a further subsidiary aspect, said sensor incorporates a single optical sensor viewing several separate fields of view. In a preferred embodiment, the sensor views 3 separate fields.
In a further subsidiary aspect, said sensor incorporates a unit with a plurality of optical sensors aimed in a plurality of directions. This configuration is also capable of segmenting the assessment per specific area.
In a further subsidiary aspect, the wheel sensor further incorporates ambient in-tyre pressure sensing means. This configuration is also particularly advantageous because it allows the sensing to take into account fluctuations in the ambient in-tyre pressure and to compare them with fluctuations in the tyre surface. It also allows for greater accuracy of the tyre surface assessment.
In a further subsidiary aspect, said sensor further incorporates means for sensing the optical sensor's body temperature. This configuration is particularly advantageous because it allows the assessment to take into account the sensor's body temperature in order to arrive closer to the actual fluctuations in tyre surface temperatures.
In a further subsidiary aspect, said sensor is configured to operate up to 125° Celsius.
In a further subsidiary aspect, said sensor is configured to operate down to −40° Celsius.
In a further subsidiary aspect, the wheel sensor further comprises means for wirelessly transmitting signals representative of sensed characteristics to a receiver. This allows the assessment to occur at a remote location from the sensor.
In a further subsidiary aspect, said sensor incorporates a unit and a temperature sensor for sensing the temperature at or in the vicinity of said wheel sensor which is in addition to said optical sensing means. This configuration is particularly advantageous because it allows the assessment to take into account fluctuations at the wheel sensor itself for a closer monitoring of the surface fluctuations in temperature.
In a further subsidiary aspect, said sensor incorporates a housing and said optical sensor is partly embedded in said housing. This allows the embedded part to be in effect protected from harsh environmental conditions. It also mechanically strengthens the optical sensor.
In a further subsidiary aspect, said sensor is located in a middle region between the edges of a wheel rim. This provides for advantageous balance in the wheel. It also allows the sensor to be fitted in a separate location from the inlet valve. It would therefore allow the inlet valve to be changed independently from the optical wheel sensor.
In a further subsidiary aspect, said wheel further incorporates a plurality of wheel sensors located at spaced apart positions about the circumference of said rim. This allows the entire circumference of said wheel to be assessed in order to identify potential hot spots at various positions about the circumference.
In a second broad independent aspect, the invention provides a wheel sensing method comprising the steps of:
This method allows the advantages listed above to be present.
In a third broad independent aspect, the invention provides a wheel sensor comprising a housing for holding an optical sensor and an attachment for securing the wheel sensor to a wheel rim, wherein said optical sensor is configured to have one or more widening fields of view to view a portion of the inside of a tyre.
In a subsidiary aspect, said optical sensor is an infrared sensor.
In a further subsidiary aspect, said sensor is configured to view the inside surface of the tyre corresponding to a tread region, and the inside surface of the tyre corresponding to lateral regions of said tyre.
In a further subsidiary aspect, said sensor is configured to separately view the inside surface of the tyre corresponding to a tread region, and the inside surface of the tyre corresponding to lateral regions of said tyre.
In a further subsidiary aspect, said sensor is configured to view a single view.
In a further subsidiary aspect, said sensor is configured to view two separate views which overlap in a region corresponding to the inside surface of the tread region.
In a further subsidiary aspect, said sensor is configured to view a plurality of separate fields of view of the inside surface of the tyre.
In a further subsidiary aspect, said sensor incorporates a unit with a plurality of optical sensors aimed in a plurality of directions.
In a further subsidiary aspect, the sensor further incorporates ambient in-tyre pressure sensing means.
In a further subsidiary aspect, said sensor further incorporates means for sensing the optical sensor's body temperature.
In a further subsidiary aspect, said sensor is configured to operate up to 125 degrees Celsius.
In a further subsidiary aspect, said sensor is configured to operate down to minus 40 degrees Celsius.
In a further subsidiary aspect, said sensor further comprises means for wirelessly transmitting signals representative of sensed characteristics to a receiver.
In a further subsidiary aspect, said sensor incorporates a unit and a temperature sensor for sensing the temperature at or in the vicinity of said wheel sensor which is in addition to said optical sensing means.
In a further subsidiary aspect, said sensor incorporates a housing and said optical sensor is partly embedded in said housing.
In a further subsidiary aspect, said sensor is located in a middle region between the edges of a wheel rim.
In a further subsidiary aspect, said wheel further incorporates a plurality of wheel sensors located at spaced apart positions about the circumference of said rim.
Whilst the location shown in
A plurality of separate wheel sensors may also be placed in any or all of these positions. In addition, the angle of the field of view may be adjusted dependent upon the area of assessment.
The wheel sensor may also incorporate the following features: ambient pressure sensing means, temperature sensing means for the sensor's own internal temperature, temperature sensing means for the optical sensor body temperature, and a wireless transmitter. The wireless transmitter may be adapted to function with a wireless receiver located in the body of a motor vehicle which may itself incorporate a further wireless transmitter for transmitting sensed data to a base station.
The wheel sensor is preferably an infrared sensor. The materials selected for the wheel sensor may be such that it can withstand harsh environments such as 125° Celsius. In a preferred embodiment, it is envisaged that the wheel sensor withstands temperatures in the range of −40° Celsius to 125° Celsius. The infrared sensor may be a single or dual zone infrared thermometer such as TO-39 supplied by Melexis.
In a further embodiment, the optical sensor may be pointing towards a rim portion to assess the rim temperature.
Number | Date | Country | Kind |
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0813230.0 | Jul 2008 | GB | national |
0814846.2 | Aug 2008 | GB | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/GB2009/050883 | 7/17/2009 | WO | 00 | 1/18/2011 |