Method for the transmission of a sensor data signal and an additonal data signal from a sensor component to a least one receiver

• US 20040128043A1
• Filed: 10/31/2003
• Published: 07/01/2004
• Est. Priority Date: 05/05/2001
• Status: Active Grant

• Current Assignee: Conti Temic Microelectronic GmbH (Continental AG)
• Original Assignee: Conti Temic Microelectronic GmbH (Continental AG)
• Inventors: Weichenberger, Lothar
• Granted Patent: US 6,944,526 B2
• Time in Patent Office: Days
• US Class Current: 701/45
• CPC Class Codes: B60R 2021/0104 Communication circuits for data transmission
• CPC Class Codes: B60R 2021/01115 specific data frames
• CPC Class Codes: B60R 2021/0117 Noise
• CPC Class Codes: B60R 21/013 including means for detecting collisions, impending collisions or roll-over
• CPC Class Codes: G08C 15/12 the signals being represented by pulse characteristics in transmission link

Abstract

A method for the transmission of sensor data from a sensor assembly to one or more receivers is presented, in which, in response to a control signal, additional data are transmitted at least temporarily for a short time instead of the sensor data, whereby only a certain limited value range of the value range that is available for the sensor data transmission is used for the transmission of the additional data, so that even with receivers which do not recognize that the transmitted data are additional data, erroneous functions or malfunctions are to be excluded. Thus, especially that value range of the sensor data signal that is to be attributed to a noise of the quantity to be measured or of the sensor assembly and is therefore not evaluated by the receiver in the normal signal operation, is used for the transmission of the additional data. In occupant protection systems, the safety-uncritical value range of a sensor data signal, which leads to no triggering of the occupant protection system, can correspondingly be used for the transmission of the additional data.

Claims

1. Method for the transmission of a sensor data signal (s11) and an additional data signal (s14) from a sensor assembly (1) to at least one receiver of the sensor data signal (2) and one receiver of the additional data signal (3, 5) through a common transmission channel (4),

a) whereby a sensor (11) measures a quantity that is to be measured and generates a corresponding sensor data signal,

b) the receiver (2) of the sensor data signal (s11) controls an application unit dependent on the sensor data signal,

c) whereby the value range of the sensor data signal (x0-xn) comprises a value range (x0-x1) that is uncritical for the control of the application unit,

d) in response to a control signal (s3/s5/s15/s16/Uon), a data transmission unit (13) of the sensor assembly (1) at least temporarily for a short time transmits an additional data signal (s14) instead of the sensor data signal (s11), whereby the value range (x0-x1) that is uncritical for the control of the application unit is used as the signal value range (y0-ym) for the additional data signal (s14).

2. Method according to claim 1, in which a certain value range (x0-x1) of the sensor data signal (s11) as a noise range is attributable to a noise of the quantity to be measured as well as of the sensor assembly, and the noise range (x0-x1) is used as the signal value range (y0-ym) for the additional data signal (s14).

3. Method according to claim 1, wherein the receiver (2) of the sensor data signal compares the sensor data signal with a threshold value (x2), and activates the application unit only with a sensor data signal (s11) exceeding the threshold value (x2), whereby the value range below this threshold value (x0-x2) is used as the signal value range (y0-ym2) for the additional data signal (s14).

4. Method according to claim 1, sensor assembly (1) in an occupant protection system for motor vehicles,

a) the sensor assembly (1) measures a safety relevant quantity and generates a sensor data signal (s11) corresponding to the safety relevant quantity,

b) at least one activation unit (2) of at least one occupant protection device is provided, which receives the sensor data signals (s11) and decides about the triggering of the occupant protection device(s) dependent on this sensor data signal (s11), whereby

c) the sensor data value range (x0-xn) of the sensor data signal (s11) comprises a safety-uncritical value range (x0-x1), and the activation unit initiates no activation of the occupant protection devices with sensor data signals (s11) in this safety-uncritical value range (x0-x1), and

d) in response to a prescribed control signal (s3, s5), the data transmission unit transmits the additional data signal (s14) while using exclusively the safety-uncritical value range (x0-x1).

5. Method according to claim 4, whereby

a) the sensor (11) is an acceleration sensor, the activation unit for the decision about the activation of the occupant protection device(s) carries out an integration of the acceleration signal and a comparison of the acceleration integral signal with an activation threshold and

b) the safety-uncritical value range used for the transmission of the additional data is determined so that the activation threshold will in no case be reached even with an integration of the largest values from the safety-uncritical value range.

6. Method according to one of the preceding claims, in which the data transmission unit (13) comprises a monitoring unit (15), which detects the present actual values of the sensor data signal (s11) at least during the transmission of the additional data signal (s14), compares the present actual values with prescribed nominal values, and upon exceeding these nominal values terminates the transmission of the additional data signal (s14) and switches to the transmission of the sensor data signal (s11).

7. Method according to one of the preceding claims, in which the data transmission is achieved in digital code words,

a) whereby among the code words, a portion is provided for the transmission of control signals and the other portion is provided for the transmission of sensor data,

b) of the code words used for the sensor data transmission, in turn a portion corresponds to sensor data that are uncritical for the control of the application unit, and

c) this portion of the code words is used for the transmission of the additional data.

8. Method according to claim 5, whereby the transmission of the additional data is carried out in a sequence of several code words and the code words of the additional data are in turn divided into additional control data and additional user data.

9. Use of the method according to one of the preceding claims for detecting sensor production data, especially an individual sensor assembly number.

10. Acceleration sensor assembly for generating an acceleration signal in an occupant protection system,

a) whereby a signal value range (+127 to −

127) is prescribed for the data transmission, this signal value range is divided into a sensor data value range (+120 to −

120) for the sensor data transmission and a control signal value range (+127 to +121 as well as −

121 to −

128), that is distinguishable therefrom, for the transmission of control signals for controlling of the data transmission,

b) at least one activation unit of at least one occupant protection device is provided, which receives the acceleration signals (s11) and decides about the triggering of the occupant protection device(s) dependent on these acceleration signals (s11), whereby

c) the sensor data value range (+120 to −

120) of the acceleration signal (s11) comprises a safety-uncritical value range (+3 to −

3) and the activation unit initiates no activation of the occupant protection devices with acceleration signals in this safety-uncritical value range (+3 to −

3), and

d) in response to a prescribed control signal, the acceleration sensor transmits additional data (s14) while using exclusively the safety-uncritical value range (+3 to −

3).

11. Acceleration sensor assembly according to claim 10, which switches from the transmission of the sensor data signal (s11) to the transmission of the additional data (s14) in response to a command of a read-out unit (5) or of a central unit (3) of the occupant protection system.

12. Acceleration sensor assembly according to claim 10, which, in response to a reset that is externally generated from the central unit (3) of the occupant protection system as well as in response to a reset that is internally generated from the acceleration sensor assembly itself, after an initialization signal, first transmits the additional data signal (s14) and subsequently switches (12) to the transmission of the sensor data signal (s11).