US 2013/0278917 A1Published application

Distance measuring system

AssigneeHonda Motor Co., Ltd.

InventorsKeisuke KOREKADO, Tomoyuki KAMIYAMA, Nobuyuki OHASHI

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Abstract

A light emission reference signal, the timing of which is adjusted by a first delay time control circuit, is input as a timing adjustment signal to a light emitter driver. The light emission reference signal, which is delayed by a second delay time control circuit, is output as an offset signal. The offset signal and a light emission timing signal from the light emitter driver are input to a timing correction phase comparator, and a phase comparison result is output from the timing correction phase comparator. The phase comparison result is input to a timing correction control logic circuit, and a delay adjusting signal based on the phase comparison result is output from the timing correction control logic circuit. The delay adjusting signal is input to the first delay time control circuit, whereby the timing of the light emission reference signal is adjusted.

Claims31

Dependent claims

A distance measuring system comprising:

a light emitter that emits light toward a target object;
a light receiver that receives reflected light of the emitted light from the target object and produces an output corresponding to an amount of light received;
a controller for controlling the light emitter and the light receiver;
and
a distance calculating unit that calculates a distance to the target object by means of a time-of-flight method using the output of the light receiver,
wherein the controller further comprises:
a sequencer that regulates a light emission timing at which light is emitted from the light emitter and a light reception timing at which light is received by the light receiver;
a reference clock signal generating unit that generates a reference clock signal and outputs the reference clock signal to the sequencer;
a light emitter driver for driving the light emitter;
a light receiver driver for driving the light receiver;
and
a timing correction unit interposed in a previous stage of the light emitter driver for correcting the light emission timing,
wherein the timing correction unit includes a first delay time control circuit, a second delay time control circuit, a timing correction phase comparator, and a timing correction control logic circuit;
the sequencer generates a reference signal synchronized with the reference clock signal, and inputs the reference signal to the first delay time control circuit and the second delay time control circuit;
the second delay time control circuit receives the reference signal, which is input thereto, and outputs an offset signal in which timing of the reference signal is delayed;
the timing correction phase comparator receives the offset signal and an output signal from the light emitter driver, which are input thereto, and outputs a phase comparison result;
the timing correction control logic circuit reads the phase comparison result, and outputs a delay adjusting signal based on the phase comparison result;
and
the first delay time control circuit reads the delay adjusting signal, adjusts the timing of the reference signal, and outputs the same as a light emission timing adjustment signal to the light emitter driver.

16 more elements

A distance measuring system comprising:

a light emitter that emits light toward a target object;
a light receiver that receives reflected light of the emitted light from the target object and produces an output corresponding to an amount of light received;
a controller for controlling the light emitter and the light receiver;
and
a distance calculating unit that calculates a distance to the target object by means of a time-of-flight method using the output of the light receiver,
wherein the controller further comprises:
a sequencer that regulates a light emission timing at which light is emitted from the light emitter and a light reception timing at which light is received by the light receiver;
a reference clock signal generating unit that generates a reference clock signal and outputs the reference clock signal to the sequencer;
a light emitter driver for driving the light emitter;
a light receiver driver for driving the light receiver;
and
a timing correction unit interposed in a previous stage of the light emitter driver for correcting the light emission timing,
wherein the timing correction unit includes a circuit startup sequence generator, a delay time control and timing correction phase comparator, and a timing correction control logic circuit;
the circuit startup sequence generator, at the time of system startup, outputs a startup trigger signal to the timing correction control logic circuit, to thereby start up driving of the timing correction control logic circuit;
the timing correction control logic circuit sets an initial value in the delay time control and timing correction phase comparator based on the startup trigger signal;
and
the circuit startup sequence generator outputs a startup signal to the delay time control and timing correction phase comparator, to thereby start up driving of the delay time control and timing correction phase comparator.

14 more elements

A distance measuring system comprising:

a light emitter that emits light toward a target object;
a light receiver that receives reflected light of the emitted light from the target object and produces an output corresponding to an amount of light received;
a controller for controlling the light emitter and the light receiver;
and
a distance calculating unit that calculates a distance to the target object by means of a time-of-flight method using the output of the light receiver,
wherein the controller further comprises:
a sequencer that regulates a light emission timing at which light is emitted from the light emitter and a light reception timing at which light is received by the light receiver;
a reference clock signal generating unit that generates a reference clock signal and outputs the reference clock signal to the sequencer;
a light emitter driver for driving the light emitter;
and
a light receiver driver for driving the light receiver,
wherein the sequencer outputs a control signal, by which the light emission timing and the light reception timing are regulated, to the light emitter driver and the light receiver driver, via a timing correction unit that carries out adjustment of a delay time based on a transition timing of the reference clock signal, and at a time resolution that is higher than the time resolution of the reference clock signal.

9 more elements

A distance measuring system comprising:

a light emitter that emits light toward a target object;
a light receiver that receives reflected light of the emitted light from the target object and produces an output corresponding to an amount of light received;
a controller for controlling the light emitter and the light receiver;
and
a distance calculating unit that calculates a distance to the target object by means of a time-of-flight method using the output of the light receiver,
wherein the controller further comprises:
a sequencer that regulates a light emission timing at which light is emitted from the light emitter and a light reception timing at which light is received by the light receiver;
a reference clock signal generating unit that generates a reference clock signal and outputs the reference clock signal to the sequencer;
a light emitter driver for driving the light emitter;
and
a light receiver driver for driving the light receiver,
wherein the sequencer outputs a control signal, by which the light emission timing is regulated, to the light emitter driver, via a timing correction unit that carries out adjustment of a delay time based on a transition timing of the reference clock signal, and at a time resolution that is higher than the time resolution of the reference clock signal.

9 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/838,053Filed 15 Mar 2013
Priority: JP 2012-06442721 Mar 2012
Published: 24 Oct 2013
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

G01C 3/08
Use of electric means to obtain final indication: use of electric radiation detectors
G01S 7/484
Details of pulse systems: transmitters
G01S 7/4865
Receivers: time delay measurement, e.g. time-of-flight measurement, time of arrival measurement or determining the exact position of a peak
G01S 7/497
Of systems according to group G01S17/00: means for monitoring or calibrating

Family

US 9,109,888 B2Related patent
US 2013/0278917 A1This patent

From the US filing history. Foreign family members aren’t listed.

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