Data processing: vehicles – navigation – and relative location – Vehicle control – guidance – operation – or indication – Vehicle diagnosis or maintenance indication
Reexamination Certificate
1999-09-30
2001-09-04
Chin, Gary (Department: 3661)
Data processing: vehicles, navigation, and relative location
Vehicle control, guidance, operation, or indication
Vehicle diagnosis or maintenance indication
C701S076000, C303S122050
Reexamination Certificate
active
06285933
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a device and a method for monitoring a transverse acceleration sensor located in a vehicle.
BACKGROUND INFORMATION
Different variations of devices and methods for monitoring a sensor located in a vehicle are known.
A circuit arrangement for evaluating the signals from a yaw rate sensor is described in European Patent No. 0 751 888. For this purpose, the signals from the yaw rate sensor are supplied to a control unit. Signals from at least one sensor—in most cases, however, a plurality of sensors—which detects driving status-dependent quantities such as the steering wheel angle, wheel rotational speeds, transverse and longitudinal acceleration, etc. are also supplied to the control unit. Based on these signals, the control unit calculates a reference yaw rate and compares it to the yaw rate measured by a sensor. For this purpose, the difference between the reference yaw rate and the yaw rate measured by the yaw rate sensor is determined and compared to a preset threshold value. A status signal, which indicates whether the yaw rate sensor is in proper working order or is defective, is emitted, based on the result of this comparison. The reference yaw rate is determined as follows: using different mathematical models, various values for the yaw rate are determined on the basis of the further sensor signals. A reference yaw rate is determined by addition, based on these values, weighted by factors that are determined with the help of fuzzy logic. Determining the reference yaw rate using fuzzy logic involves a considerable amount of effort.
A device and a method for monitoring a yaw rate sensor, a transverse acceleration sensor, a steering angle sensor, and wheel speed sensors that are located in a vehicle are described in German Patent No. 196 36 443. Using mathematical models to which the sensor signal determined by the sensor is supplied, a yaw rate is determined for the yaw rate sensor, transverse acceleration sensor, steering angle sensor, and wheel speed sensors. A reference yaw rate is determined on the basis of these yaw rates determined for the different sensors. Using an inverted mathematical model for the various sensors, a sensor reference quantity is determined on the basis of this reference yaw rate. The individual sensors are monitored with the aid of this sensor reference quantity. This device and this method are used to simultaneously monitor multiple sensors provided in a vehicle. It is not possible, however, to monitor a single sensor.
A control device with an acceleration sensor and an error control unit for motor vehicles is described in German Patent No. 39 30 302. This control device includes a first acceleration sensor for detecting longitudinal accelerations and a second acceleration sensor, for example, for detecting transverse accelerations. The control device also includes a facility for recording the signals from the acceleration sensors and for deriving a data value on the basis of the two signals. The data value is compared to a preset comparison value in a further facility and an error in one of the sensor signals is detected. The data value is derived, for example, by adding up the acceleration signals or determined as the root of the sum of the squares of the acceleration signals. The use of a transverse acceleration quantity determined directly as a function of wheel speed quantities is not described.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a device and a method for monitoring a transverse acceleration sensor located in a vehicle that can be used to monitor the transverse acceleration sensor with the least amount of effort, using a second transverse acceleration signal that is not determined by a transverse acceleration sensor.
The device according to the present invention concerns a device for monitoring a transverse acceleration sensor located in a vehicle and detecting a first transverse acceleration quantity that describes the transverse acceleration acting upon the vehicle. The device includes a determining means used to determine a second transverse acceleration quantity. A comparison between the first transverse acceleration quantity and the second transverse acceleration quantity is carried out in monitoring means to monitor the transverse acceleration sensor.
The transverse acceleration sensor is located in a vehicle that is equipped with an anti-skid system, i.e., an anti-skid braking system and/or a traction control system. Such anti-skid systems are equipped as standard with wheel speed sensors. To avoid the need for additional sensors, it can thus be advantageous to determine the second transverse acceleration quantity as a function of the quantities detected by the wheel speed sensors. For this reason, the device includes detecting means used to detect wheel speed quantities describing the speeds of the wheels. The second transverse acceleration quantity is determined in the determining means directly as a function of the wheel speed quantities.
According to a further advantage, the first transverse acceleration quantity is filtered before being supplied to the monitoring means. This filtering achieves two goals: first, it eliminates any noise that may exist in the first transverse acceleration quantity. Secondly, it suppresses components of the first transverse acceleration quantity that can be attributed to a rocking or vibrating motion of the vehicle structure. For this purpose, the device includes processing means that have at least one filtering means, in particular a low-pass filter. These processing means are used to filter the first transverse acceleration quantity, thus yielding a filtered transverse acceleration quantity.
In addition, it is advantageous to provide the processing means with further means for processing the first transverse acceleration quantity. These can be conversion means, for example, used to convert the first transverse acceleration quantity (which is an analog quantity) into a digital transverse acceleration quantity; and/or scaling means used to vary the resolution of the first transverse acceleration quantity; and/or correction means used to correct the zero position of the first transverse acceleration quantity; and/or first limiting means used to limit the maximum and minimum values of the first transverse acceleration quantity to physically reasonable values; and/or error response means; and/or second limiting means used to limit the increase in the first transverse acceleration quantity.
To detect the wheel speed quantities, the detecting means advantageously have wheel speed sensors, used to determine wheel rotational speed quantities, and conversion means, used to determine the wheel speed quantities as a function of the wheel rotational speed quantities.
Determining the second transverse acceleration quantity directly as a function of the wheel speed quantities of the non-driven wheels and of the vehicle track gauge has proven to be advantageous. Using the non-driven wheels ensures that the second transverse acceleration quantity is not corrupted by drive slippage.
According to the present invention, the second transverse acceleration quantity is determined as a function of a difference quantity and/or a mean quantity, both of which are determined as a function of the wheel speed quantities of the non-driven wheels. The difference quantity represents the difference between the wheel speed of the left and right non-driven wheels. The mean quantity describes the mean value of the wheel speeds of the left and right non-driven wheels.
It is advantageous to monitor the acceleration sensor only if at least one condition has been met. This avoids vehicle operating states that could corrupt the monitoring result. Monitoring is carried out if a quantity describing the vehicle speed exceeds a threshold value; and/or if no braking action has occurred; and/or if an anti-skid system provided in the vehicle, in particular an anti-skid braking system, is inactive; and/or if the wheel speed quantities have been correcte
Braun Guenter
Kohler Rolf
Kottmann Matthias
Schmitt Johannes
Zoebele Andreas
Chin Gary
Kenyon & Kenyon
Robert & Bosch GmbH
LandOfFree
Device and method for monitoring a transverse acceleration... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Device and method for monitoring a transverse acceleration..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Device and method for monitoring a transverse acceleration... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2450614