US 12,235,776 B2Granted

Sensor and sensor network

AssigneeRobert Bosch GmbH

InventorsSteffen Walker, Ricardo Erckert

Life of this patent

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Abstract

A sensor and a sensor network. The sensor comprises a switchable RC low-pass filter, an evaluation unit, a synchronization unit, and a two-wire interface. The two-wire interface is configured to be connected to a control device to receive an electrical supply voltage, provided by the control device, for supplying the sensor with electrical energy, to receive sync pulses superimposed on the supply voltage for synchronizing a data transmission from the control device, and to transmit data to the control device. The RC low-pass filter generates a reference signal by low-pass filtering an input signal, and to have a first time constant in a first mode and a second time constant in a second mode, wherein the second time constant is shorter than the first time constant. The evaluation unit stabilizes the reference signal by alternately switching the RC low-pass filter into the first mode and into the second mode.

Claims9

Dependent claims

A sensor, comprising:

a switchable RC low-pass filter;
an evaluation unit;
a synchronization unit;
and
a two-wire interface;
wherein the two-wire interface is configured:
to be connected to a control device to receive an electrical supply voltage, provided by the control device, for supplying the sensor with electrical energy,
to receive sync pulses superimposed on the supply voltage for synchronizing a data transmission from the control device, and
in a predefined time window, with respect to a sync point in time established by the synchronization unit, to transmit data to the control device, as a result of which data pulses resulting from the data transmission are superimposed on the supply voltage;
wherein the switchable RC low-pass filter is configured:
to generate a reference signal by low-pass filtering an input signal of the RC low-pass filter, wherein a waveform of the input signal corresponds with a waveform of the supply voltage that is superimposed,
to have a first time constant in a first mode of the RC low-pass filter, and
to have a second time constant in a second mode of the RC low-pass filter, wherein the second time constant is shorter than the first time constant;
wherein the evaluation unit is configured to stabilize the reference signal by:
switching the RC low-pass filter into the first mode at least when a sync pulse or data is superimposed on the supply voltage, and
switching the RC low-pass filter into the second mode at least in a period between two sync pulses in which no data are superimposed on the supply voltage;
and
wherein the synchronization unit is configured:
to form a difference signal from the input signal and the reference signal, and
to determine a sync point in time whenever the difference signal exceeds a predefined threshold value.

17 more elements

A sensor network, comprising:

at least two sensors, each of the sensors including:
a switchable RC low-pass filter;
an evaluation unit;
a synchronization unit;
and
a two-wire interface;
wherein the two-wire interface is configured:
to be connected to a control device to receive an electrical supply voltage, provided by the control device, for supplying the sensor with electrical energy,
to receive sync pulses superimposed on the supply voltage for synchronizing a data transmission from the control device, and
in a predefined time window, with respect to a sync point in time established by the synchronization unit, to transmit data to the control device, as a result of which data pulses resulting from the data transmission are superimposed on the supply voltage;
wherein the switchable RC low-pass filter is configured:
to generate a reference signal by low-pass filtering an input signal of the RC low-pass filter, wherein a waveform of the input signal corresponds with a waveform of the supply voltage that is superimposed,
to have a first time constant in a first mode of the RC low-pass filter, and
to have a second time constant in a second mode of the RC low-pass filter, wherein the second time constant is shorter than the first time constant;
wherein the evaluation unit is configured to stabilize the reference signal by:
switching the RC low-pass filter into the first mode at least when a sync pulse or data is superimposed on the supply voltage, and
switching the RC low-pass filter into the second mode at least in a period between two sync pulses in which no data are superimposed on the supply voltage;
and
wherein the synchronization unit is configured:
to form a difference signal from the input signal and the reference signal, and
to determine a sync point in time whenever the difference signal exceeds a predefined threshold value;
and
the control device electrically connected to the at least two sensors via the two-wire interface, and configured to, using the two-wire interface:
supply the sensors with the supply voltage, and
receive data from the at least two sensors.

22 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/798,149Filed 5 Aug 2021
Priority: DE 10 2020 209 879.45 Aug 2020
Published: US 2023/0102989 A130 Mar 2023
Granted: 25 Feb 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

G06F 13/10
Interconnection of, or transfer of information or other signals between, memories, input/output devices or central processing units: program…
G06F 13/4068
Device-to-bus coupling: electrical coupling
G06F 13/4256
On a daisy chain bus: using a clocked protocol
G06F 13/4273
On a point to point bus: using a clocked protocol