Patent Application
20080100429
The embodiments described herein relate to a tire pressure monitoring (TPM)/remote keyless entry (RKE) system for a vehicle having a TPM/RKE module configured to operate in a TPM mode and a RKE mode.
Tire pressure monitoring (TPM) systems are installed on vehicles for providing vehicle occupants information relating to the condition of vehicle wheels. Remote keyless entry (RKE) systems enable remote entry to vehicles through the use of a handheld wireless devices such as key fobs. To enable the TPM and RKE functions, conventional vehicles utilize a number of electronic devices that are dedicated to either the TPM system or the RKE system. As such, some hardware redundancies exist and the cost of hardware dedicated to both TPM and RKE systems is prohibitive.
The embodiments described herein were conceived in view of these and other disadvantages of conventional TPM/RKE systems.
The embodiments described herein include a tire pressure monitoring (TPM)/remote keyless entry (RKE) system and method for a vehicle. The system includes a TPM sensor configured to sense the condition of a vehicle tire and transmit a TPM sensor signal during a first predetermined time period. A RKE device is included that is configured to transmit a RKE signal during a second predetermined time period. Additionally, a TPM/RKE module is configured to operate in a TPM mode and a RKE mode. The TPM/RKE module receives the TPM sensor signal during the TPM mode and the RKE signal during the RKE mode. The TPM/RKE module is also configured to automatically transition between the TPM mode and the RKE mode in accordance with the first and the second predetermined time periods.
The novel features of the described embodiments are set forth with particularity in the appended claims. These embodiments, both as to their organization and manner of operation, together with further advantages thereof, may be best understood with reference to the following description, taken in connection with the accompanying drawings in which:
As required, detailed descriptions of embodiments are disclosed herein. However, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale, and some features may be exaggerated or minimized to show details of particular components. Therefore, specific functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for the claims and/or as a representative basis for teaching one skilled in the art.
Referring to
TPM sensors 16 are adapted to sense the condition of wheels 14 and generate TPM sensor signals that correspond to the condition of wheels 14. In one embodiment, TPM sensors 16 do not contain an internal power supply such as a battery. During operation, a TPM/RKE module 20 generates interrogation signals that energize TPM sensors 16 causing the TPM sensors 16 to generate TPM sensor signals. TPM sensor antennas 18 enable TPM sensor signals from TPM sensors 16 to be received and processed by TPM/RKE module 20.
As described above, doors 13 have a locked and unlocked state. TPM/RKE module 20 generates control signals for a body control module 26 to generate signals causing doors 13 to enter the unlocked and locked states. TPM/RKE module 20 also includes a RKE antenna 24 for receiving RKE signals from a device 28. Device 28 may be a key fob having a plurality of buttons for unlocking and locking doors 13, starting an engine of vehicle 12, controlling various vehicle accessories and the like. When a RKE signal is generated by device 28, the RKE antenna 24 is adapted to receive the RKE signals. TPM/RKE module 20 processes the RKE signals and generate corresponding control signals for body control module 26, which generates signals for unlocking and locking doors 13. The RKE system described herein may be a two-way RKE system. As such, communications between device 28 and TPM/RKE module 20 would be bi-directional. With the two-way RKE system embodiment, in addition to locking and unlocking doors 13, device 28 may be configured to control various vehicle functions such as heating, ventilation and air conditioner (HVAC) functions and download information from vehicle 12.
TPM/RKE module 20 is also configured to receive and process TPM sensor signals and RKE signals. As described above, TPM/RKE module 20 is also configured to generate signals (referred to as interrogation signals) for TPM sensor 16 that cause TPM sensors 16 to generate the TPM sensor signals.
TPM/RKE module 20 has at least two operating modes including a TPM mode and a RKE mode. TPM/RKE module 20 is also configured to automatically transition between the TPM mode and the RKE mode. In one embodiment, the TPM mode and the RKE mode may be partitioned by time periods (e.g., a first time period and a second time period). To enable operation in the TPM and RKE mode, TPM/RKE module 20 includes a controller having data storage and processing functionality. The controller of TPM/RKE module 20 is programmed to identify the respective time periods for determining whether to operate in the TPM mode or the RKE mode. Accordingly, TPM/RKE module 20 is further configured to transition between the TPM mode and the RKE mode when either the first time period or the second time period has been reached.
Referring to
When switch 30 is positioned to allow TPM/RKE module 20 to receive signals, the received signals are filtered by a filter 32 and amplified by low noise amplifier 34. It is recognized that the signals that are processed by filter 32 and low noise amplifier 34 typically have a high frequency. As such, to lower the frequency, a mixer 36 mixes the signals received from the low noise amplifier 34 with signals from a frequency synthesizer 50. Frequency synthesizer 50 and reference oscillator 52 provide the additional signals that, when mixed with the signal from the lower noise amplifier 34, yield a signal having a lower frequency. As such, the resulting signal from mixer 36 has a lower frequency, which is filtered by an intermediate frequency (IF) filter 38. Following filtering of the signal by filter 38, an amplifier 40 amplifies the filtered signal. An analog/digital converter 42 converts the signal from an analog format to a digital format for processing by controller 44. In the case of the TPM/RKE module 20 operating in the RKE mode, the controller 44, having received the signal from analog/digital converter 42, will generate signals for door actuators 48, via the body control module, to unlock or lock doors 13 (
When switch 30 is positioned so as to allow TPM/RKE module 20 to transmit signals, controller 44 generates control signals that enable the transmission of such signals. In one aspect, during the TPM mode, TPM/RKE module 20 is adapted to generate the interrogation pulse signal for TPM sensors 16 that enable TPM sensors 16 to generate the TPM sensor signals. Alternatively, TPM/RKE module 20 may generate a module response signal in response to a RKE interrogation signal typically generated by a key fob (e.g., device 28 in
Controller 44 is further configured to generate signals that are transmitted via antennas 18 and 24 in accordance with the various operating modes (i.e., the TPM mode and the RKE mode). When controller 44 generates a signal that is to be wirelessly transmitted by TPM/RKE module 20, the signal is initially amplified by a power amplifier 54. Frequency synthesizer 50 also generates a signal that is received by power amplifier 54. Accordingly, the power amplifier amplifies the signals from controller 44 and frequency synthesizer 50. The amplified signals are routed through switch 30 and transmitted by antennas 18 and 24. It is recognized that the specific arrangement of electrical components as shown by the schematic diagram of
Now, referring to
As indicated by the “funnel” like profile, the TPM sensor signal 68 may be attenuated over time (between T2 and T3). Between the times T2 and T3, as the TPM sensor signal 68 is being transmitted by the TPM sensor, a receiving phase 70 exists wherein the TPM/RKE module receives the TPM sensor signal 68. At the time T3, which is when the first time period for the TPM mode is reached, the TPM/RKE module automatically transitions from the TPM mode to the RKE mode 65.
At T3, which starts a second time period (i.e., the RKE mode), a RKE interrogation signal 72 may be received by the TPM/RKE module. As described in the foregoing, the RKE interrogation signal may be generated by a key fob or other wireless device. The RKE interrogation signal may be a request to lock or unlock doors on the vehicle. As such, between times T3 and T4, a receiving phase 74 occurs, wherein the TPM/RKE module is adapted to receive signals. At the time T4 through T5, however, a receive/transmit switching event 76 occurs wherein the TPM/RKE module switches from the receiving phase to the transmitting phase. As such, at T5, in response to the RKE interrogation signal, the TPM/RKE module generates a module response signal 78. This module response signal, which occurs during transmit phase 80 may be received by the body control module so as to cause the body control module to generate signals that unlock doors on the vehicle.
While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.
