Patent Application
20080018444
Referring to
The four tires 24a-24d are equipped with respective known electronic modules (“tags”) 34a-34d, respectively, and known respective tire condition sensors 33a-33d that are capable of monitoring one or more conditions such as air pressure and/or air temperature within a respective tire. Each tag is operative to transmit radio frequency (RF) signals indicative of, or modulated as a function of, one or more monitored conditions within a respective vehicle tire. In one exemplary embodiment, the tags 34a-34d are transponders such as those used with radio frequency identification tags but may alternatively simply comprise one or more condition sensors and a radio frequency transmitter.
The system 20 also has four known monitors or interrogation units 36a-36d associated with respective tires 24a-24d and preferably located in proximity therewith, for example, mounted within respective wheel wells of the vehicle 22 in a known manner. The monitors 36a-36d are connected to a source of power (not shown) and are also connected to the serial data bus 26 for individually communicating with the ECU 28. The monitors 36a-36d have respective antenna 38a-38d and respective transmitter/receivers (not shown) for transmitting signals to, and receiving signals from, respective tags 34a-34d. The monitors 36a-36d may be implemented using a data transceiver, for example, a DS36277 Dominant Mode Multipoint Transceiver commercially available from National Semiconductor of Santa Clara, Calif.
A monitor's transmissions to a respective tag may comprise a carrier signal for energizing a passive tag, and may comprise signals to “wake up” an active tag which is in a low-power sleep mode. It is within the scope of the invention that all components of a monitor 36a-36d including a respective antenna 38a-38d can be encapsulated in a single package. Alternatively, the antenna can be disposed outside of such a package.
Monitored tire condition data carried by the RF signals from tags 34a-34d may be decoded, for example, demodulated, provided to the ECU 28 and presented to a user via the touch screen display 32. In a known manner, visual warnings and alarms may be presented to a user via the touch screen 32. In other known embodiments, audible warnings and alarms may be presented to a user by the ECU 28 activating an audio signal generator 40. The audible signals may be in the form of synthesized voice messages and/or beeps, chimes, buzzes or other sounds of differing durations and/or frequencies or other audio signals. The exact form of the sensory perceptible signals, for example, the audible and visual warnings and alarms, is often determined by a vehicle manufacturer. Additionally, the information regarding dynamic conditions of the tires can be utilized in controlling the vehicle, such as by providing relevant inputs to a “smart” suspension system.
A process for utilizing the tire pressure monitoring system 20 of
Thereafter, at 310, the ECU 28 then monitors the air pressure in each of the tires 24a-24d to detect whether air pressure in any of the tires changes. If a tire pressure change is detected, then, at 312, ECU 28 determines whether the tire in which the pressure is changing is one of the tires requiring an adjustment to its air pressure, for example, tires 24b or 24c as indicated by the respective displays 46 and 48. If the air pressure in any of the other tires is changing, for example, tires 24a or 24d, in which the pressure is acceptable as shown by displays 44 and 50, the ECU 28 then, at 314, generates a wrong tire alarm signal. Such a signal may be an audible alarm provided by the audio signal generator 40 and/or a visual alarm on the display 32, which is created, for example, by changing the color of the displays 44, 50 or causing the displays 44, 50 to blink.
If, at 312, the ECU 28 determines that the tire pressure being changed corresponds to a tire having a tire pressure error, for example, tires 24b or 24c, the ECU 28 then, at 316, continues to monitor the change in tire pressure until it reaches an acceptable level. At that point, the ECU 28 outputs, at 318, a correct pressure signal that is represented on the display 32 by the acceptable icon 52. In addition upon reaching an acceptable tire pressure level, the displays 46, 48 may switch to a green color, either as a solid color or blinking. In addition, an audible signal representing an acceptable tire pressure may be created by the audio signal generator 40. The ECU 28 then, at 320, determines whether all of the tires have an acceptable pressure. If a tire pressure error still exists, the process described with respect to steps 304-320 is repeated. Upon ECU 28 determining that all of the tires 24a-24d are at an acceptable pressure, then, at 322, the ECU 28 generates an appropriate visual display and/or audio signal.
While the present invention has been illustrated by a description of various embodiments and while these embodiments have been described in considerable detail, it is not the intention of Applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention in its broadest aspects is not limited to the specific details shown and described. Consequently, departures may be made from the details described herein without departing from the spirit and scope of the claims which follow.
