Method and device for synchronizing sensors
AssigneeRobert Bosch GmbH
InventorsDorde CVEJANOVIC, Jan HAYEK
Life of this patent
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Abstract
A method for synchronizing sensors. A ratio of a first data rate of the first sensor to the second data rate of the second sensor is 2n, where n is an element from the set of natural numbers. A central timer is started. A first countdown timer is generated based on the central timer and the first data rate, and a second countdown timer is generated based on the central timer and the second data rate. The first countdown timer and the second countdown timer are started periodically. The measurement by the first sensor begins at the latest when a first latency equals the value of the first countdown timer, and the measurement by the second sensor begins at the latest when the second latency equals the value of the second countdown timer.
Claims15
1-14. (canceled)
A method for synchronizing sensors, comprising:
- (a) determining at least one first latency of a first sensor and a second latency of a second sensor;
- (b) acquiring at least one first data rate of the first sensor and a second data rate of the second sensor, a ratio of the first data rate to the second data rate being 2n, where n is an element from the set of natural numbers;
- (c) starting a central timer;
- (d) generating a countdown timer as a function of a value of the central timer and of the first data rate, and generating a second countdown timer as a function of the value of the central timer and of the second data rate;
- (e) providing the first countdown timer for the first sensor and providing the second countdown timer for the second sensor, a measurement by the first sensor beginning at the latest when the first latency equals a value of the first countdown timer, and a measurement by the second sensor beginning at the latest when the second latency equals the value of the second countdown timer;
- and
- (f) synchronously outputting a first measured value of the first sensor and a second measured value of the second sensor.
The method as recited in claim 14, wherein at least one of:
- (i) the first latency is determined in method step (a) by ascertaining from a table a duration from a response by the first sensor until the output of the first measured value, as a function of the configuration of the first sensor, and (ii) the second latency is determined in method step (a) by ascertaining from a table a duration from a response by the second sensor until the output of the second measured value, as a function of a configuration of the second sensor.
The method as recited in claim 14, wherein the first countdown timer and the second countdown timer are generated in method step (d) by inverting a value of the central timer bit by bit, and utilizing a first number of lower bits for the first countdown timer as a function of the first data rate, and utilizing a second number of lower bits for the second countdown timer as a function of the second data rate.
The method as recited in claim 14, wherein at least one of:
- (i) the first sensor is placed into a sleep mode after the first measured value is output, when the first latency is less than a reciprocal of the first data rate, and (ii) the second sensor is placed into a sleep mode after the second measured value is output, when the second latency is less than a reciprocal of the second data rate.
The method as recited in claim 14, wherein at least one of:
- (i) the first sensor is awakened at the latest when the value of the first countdown timer corresponds to the first latency, and (ii) the second sensor is awakened at the latest when the value of the second countdown timer corresponds to the second latency.
The method as recited in claim 14, wherein the first measured value and the second measured value, which are output at the same time, are combined into a data packet, the data packet being provided with a time stamp.
A device for synchronizing sensors, the sensors including at least one first sensor and a second sensor, the device comprising:
- a central timer;
- and
- a processing unit, wherein the device is configured for determining a first latency of a first sensor and a second latency of a second sensor, and the first sensor being configured for outputting a first measured value and the second sensor being configured for outputting a second measured value in synchronization with one another, and wherein the processing unit is configured to
- acquire a first data rate of the first sensor and a second data rate of the second sensor, a ratio of the first data rate to the second data rate being 2″, where n is an element from the set of natural numbers,
- start the central timer,
- generate a first countdown timer as a function of a value of the central timer and of the first data rate, and generate a second countdown timer as a function of the value of the central timer and of the second data rate, and
- provide the first countdown timer for the first sensor and provide the second countdown timer for the second sensor, the measurement by the first sensor beginning at the latest when the first latency equals a value of the first countdown timer, and the measurement by the second sensor beginning at the latest when the second latency equals the value of the second countdown timer.
Dependencies are inferred from the claim text.