阅读说明：本技术 用于飞行时间接收器的随机硬件故障和劣化保护装置 (Random hardware fault and degradation protection device for time-of-flight receiver ) 是由 M·格雷夫林 A·加杰达德齐尤 S·门德尔 F·塞克利 于 2019-12-06 设计创作，主要内容包括：本公开涉及用于飞行时间接收器的随机硬件故障和劣化保护装置。一种飞行时间光检测系统包括：沿着包括多个信号通道的信号路径顺序布置的多个电路,多个电路包括第一电路和布置在第一电路下游的第二电路；被配置为生成多个参考信号的参考信号源,其中多个信号通道中的每个信号通道在第一电路处接收多个参考信号中的至少一个参考信号；以及耦合到多个信号通道以从信号路径接收经处理的参考信号的评估电路,评估电路还被配置为将经处理的参考信号与第一期望结果进行比较以生成第一比较结果。(The present disclosure relates to random hardware fault and degradation protection devices for time-of-flight receivers. A time-of-flight light detection system comprising: a plurality of circuits arranged sequentially along a signal path including a plurality of signal channels, the plurality of circuits including a first circuit and a second circuit arranged downstream of the first circuit; a reference signal source configured to generate a plurality of reference signals, wherein each signal channel of the plurality of signal channels receives at least one reference signal of the plurality of reference signals at the first circuit; and an evaluation circuit coupled to the plurality of signal channels to receive the processed reference signal from the signal path, the evaluation circuit further configured to compare the processed reference signal to a first expected result to generate a first comparison result.)

1. A time-of-flight light detection system comprising:

a plurality of circuits arranged sequentially along a signal path including a plurality of signal channels, the plurality of circuits including a first circuit and a second circuit arranged downstream of the first circuit;

a reference signal source configured to generate a plurality of reference signals, wherein each signal channel of the plurality of signal channels receives at least one reference signal of the plurality of reference signals at the first circuit; and

an evaluation circuit coupled to the plurality of signal channels to receive the processed reference signal from the signal path, the evaluation circuit further configured to compare the processed reference signal to a first desired result to generate a first comparison result.

2. The time of flight light detection system of claim 1, in which the reference signal source is a current source and the plurality of reference signals are current reference signals.

3. The time of flight light detection system of claim 1, in which the evaluation circuit is configured to receive a plurality of processed reference signals from the signal path, each of the plurality of processed reference signals being derived from at least one of the plurality of reference signals, and the evaluation circuit is further configured to compare each of the plurality of processed reference signals to at least one of a plurality of expected results to generate a plurality of first comparison results.

4. The time of flight light detection system of claim 3, in which the evaluation circuit is configured to receive the plurality of processed reference signals from at least two extraction points of the signal path.

5. The time of flight light detection system of claim 4, in which the at least one extraction point comprises a first extraction point upstream of the second circuit and a second extraction point downstream of the second circuit.

6. The time of flight light detection system of claim 3, wherein the evaluation circuit is configured to:

at least one characteristic of the plurality of signal paths is evaluated based on the plurality of first comparison results, and whether the signal path is operating properly is determined based on the at least one characteristic.

7. The time of flight light detection system of claim 1, in which the first circuit is a light detector circuit and the second circuit is one of an amplifier circuit or an analog-to-digital converter circuit.

8. The time-of-flight light detection system of claim 1, wherein:

the first circuit includes a photodetector array configured to generate an electrical signal based on received light,

the reference signal source is configured to inject one of the plurality of reference signals into each of the plurality of signal channels at the first circuit such that each reference signal is combined with at least one of the electrical signals to generate a combined signal, the combined signal processed by the signal path to generate a processed combined signal, an

The evaluation circuit is configured to receive the processed combined signal from the signal path, the evaluation circuit further configured to compare the processed combined signal with a second desired result to generate a second comparison result.

9. The time of flight light detection system of claim 8, further comprising:

a filter configured to receive the processed combined signal from the signal path and filter the plurality of reference signals from the processed combined signal to recover the electrical signal; and

a signal processing circuit configured to generate object data based on the recovered electrical signal.

10. The time of flight light detection system of claim 8, further comprising:

a signal processing circuit configured to receive the processed combined signal from the signal path and generate first object data based on the processed combined signal; and

a filter configured to receive the first object data from the signal processing circuit, detect virtual object data corresponding to the plurality of reference signals in the first object data, and remove the detected virtual object data from the first object data to generate second object data.

11. The time of flight light detection system of claim 8, wherein the evaluation circuit is configured to:

at least one characteristic of the plurality of signal channels is evaluated based on the second comparison result, and it is determined whether the signal path is operating properly based on the at least one characteristic.

12. The time of flight light detection system of claim 1, further comprising:

a memory device configured to store information corresponding to a plurality of different current pulse patterns;

a selection element configured to select one of the plurality of different current pulse patterns and to control the reference signal source to generate at least one of the plurality of reference signals based on the selected one of the plurality of different current pulse patterns.

13. The time-of-flight light detection LIDAR receiver system of claim 12, further comprising:

a system controller configured to modify a configuration of the signal path, and

wherein the selection element is configured to select one of the plurality of different current pulse patterns based on the configuration of the signal path.

14. The time-of-flight light detection LIDAR receiver system of claim 13, wherein the configuration of the signal path is a gain setting of at least one of the first circuit or the second circuit, wherein:

for a first gain setting, the selection element is configured to select a first current pulse pattern of the plurality of different current pulse patterns,

for a second gain setting, the selection element is configured to select a second current pulse pattern of the plurality of different current pulse patterns, and

the first gain setting is greater than the second gain setting, and the first one of the plurality of different current pulse patterns has an amplitude that is less than an amplitude of the second one of the plurality of different current pulse patterns.

15. The time of flight light detection system of claim 1, in which the first circuit comprises an analog multiplexer coupled to the plurality of signal channels and configured to receive the plurality of reference signals as inputs and to route each of the plurality of reference signals to a different one of the plurality of signal channels.

16. The time-of-flight light detection system of claim 15, wherein the reference signal source and the analog multiplexer are controlled to effect time shifting of the plurality of reference signals such that adjacent ones of the plurality of signal channels receive corresponding ones of the plurality of reference signals at different times.

17. The time-of-flight light detection system of claim 1, wherein:

a plurality of first time intervals interleaved with a plurality of second time intervals, wherein the first circuit comprises a photodetector array configured to generate an electrical signal based on received light during the plurality of first time intervals, wherein the photodetector array does not provide a signal to the signal path during the plurality of second time intervals, and

the reference current source is configured to inject the plurality of reference signals into the plurality of signal channels at the first circuit during the plurality of second time intervals.

18. The time of flight light detection system of claim 1, further comprising:

a control unit for the system, wherein the control unit is provided with a control unit,

wherein the evaluation circuit is configured to detect a fault in the time of flight light detection system based on the first comparison result and indicate the fault to the system controller, and

the system controller is configured to receive the fault and, in response to the fault, perform at least one of: disabling the time-of-flight light detection system, reducing the performance of the time-of-flight light detection system, or deprioritizing a LIDAR sensor relative to another object scanning sensor.

19. The time of flight light detection system of claim 1, in which the reference signal source is configured to inject the plurality of reference signals between two light acquisition phases of the time of flight light detection system.

20. The time of flight light detection system of claim 1, in which the reference signal source is configured to inject the plurality of reference signals during a light acquisition phase of the time of flight light detection system.

21. A time-of-flight light detection receiver system comprising:

a plurality of circuits arranged sequentially along a signal path including a plurality of signal channels, the plurality of circuits including a first circuit and a second circuit arranged downstream of the first circuit;

a reference signal source configured to generate a plurality of reference signals, each of the plurality of signal channels receiving at least one of the plurality of reference signals at the first circuit;

the first circuitry comprising a plurality of readout elements and a plurality of photodetector readout channels representing a first portion of the plurality of signal channels and coupled to the plurality of readout elements, the plurality of readout elements configured to selectively route the plurality of reference signals to the plurality of photodetector readout channels;

the second circuit comprising a plurality of processing channels representing a second portion of the plurality of signal channels, the plurality of processing channels comprising a plurality of processing elements configured to generate processed reference signals derived from the plurality of reference signals and to output the processed reference signals from the second circuit; and

an evaluation circuit coupled to the signal path to receive ones of the processed reference signals, the evaluation circuit configured to compare the processed reference signals to a first desired result to generate a first comparison result.

22. A method of evaluating at least one characteristic of a plurality of signal channels in a time-of-flight light detection system, the time-of-flight light detection system comprising a plurality of circuits arranged sequentially along a time-of-flight light detection signal path comprising the plurality of signal channels, the plurality of circuits comprising a first circuit and a second circuit arranged downstream of the first circuit, the method comprising:

generating a plurality of reference signals;

injecting at least one of the plurality of reference signals into each of the plurality of signal channels at the first circuit such that the plurality of reference signals are processed in the signal path;

comparing the processed reference signal to an expected result to generate a comparison result;

evaluating the at least one characteristic of at least one of the plurality of signal channels based on the comparison; and

determining whether any of the first circuit or the second circuit is defective based on the evaluated at least one characteristic of the at least one of the plurality of signal channels.

Technical Field

The present disclosure relates generally to apparatus and methods for time-of-flight (TOF) receivers.

Background

Light detection and ranging (LIDAR) is a remote sensing method that uses light in the form of pulsed laser light to measure range (variable distance) to one or more objects in the field of view. In particular, light is emitted towards the object. A single light detector or an array of light detectors receives reflections from objects illuminated by light, and the time taken for the reflections to reach the various sensors in the array of light detectors is determined. This is also known as measuring time of flight (TOF). The LIDAR system forms a depth measurement and makes a distance measurement by mapping the distance to an object based on a time-of-flight calculation. Thus, time-of-flight calculations can create distance and depth maps for generating images.

LIDAR receiver systems require ISO 26262-compatible development according to ASIL-B/-C/-D. The photodetector current signal needs to reliably propagate along the receiver signal path to the LIDAR system controller Integrated Circuit (IC) and report in the event of a bias/fault to meet this requirement.

In current LIDAR systems, additional laser diode flash lamps, point lasers or bar lasers are used to perform a continuous inspection of the optical system comprising the photodetector array. This is a basic check of the photo-detector unit and will not be sufficient to check all technology-related parameters of the receiver IC, such as gain, cut-off frequency, group delay, etc.

Accordingly, there may be a need for an improved apparatus having an improved way of monitoring a receiver signal path.

Disclosure of Invention

Drawings

Embodiments are described herein with reference to the drawings.

Fig. 1 is a schematic diagram of a LIDAR scanning system in accordance with one or more embodiments;

fig. 2 is a schematic block diagram of a LIDAR scanning system in accordance with one or more embodiments;

FIG. 3 is a schematic block diagram of an electrical signal path of a LIDAR receiver in accordance with one or more embodiments;

fig. 4 is a signal diagram of a plurality of signal channels into which reference signals are injected implemented in a LIDAR system in accordance with one or more embodiments;

FIGS. 5A and 5B are reference signal diagrams of example pulse patterns in accordance with one or more embodiments;

FIG. 6 is a schematic block diagram of an electrical signal path of a LIDAR receiver in accordance with one or more embodiments;

FIG. 7 is a schematic block diagram of an electrical signal path of a LIDAR receiver in accordance with one or more embodiments;

FIG. 8 is a schematic block diagram of an electrical signal path of a LIDAR receiver in accordance with one or more embodiments; and

fig. 9 is a schematic block diagram of an electrical signal path of a LIDAR receiver in accordance with one or more embodiments.

Embodiments provide time-of-flight systems and methods of operation thereof, and more particularly to detecting hardware faults and degradations in a time-of-flight receiver.

In accordance with one or more embodiments, a time-of-flight light detection system includes: a plurality of circuits arranged sequentially along a signal path including a plurality of signal channels, the plurality of circuits including a first circuit and a second circuit arranged downstream of the first circuit; a reference signal source configured to generate a plurality of reference signals, wherein each signal channel of the plurality of signal channels receives at least one reference signal of the plurality of reference signals at the first circuit; and an evaluation circuit coupled to the plurality of signal channels to receive the processed reference signal from the signal path, the evaluation circuit further configured to compare the processed reference signal to a first expected result to generate a first comparison result.

In accordance with one or more embodiments, a time-of-flight light detection receiver system comprises: a plurality of circuits arranged sequentially along a signal path including a plurality of signal channels, the plurality of circuits including a first circuit and a second circuit arranged downstream of the first circuit; a reference signal source configured to generate a plurality of reference signals, each of the plurality of signal channels receiving at least one of the plurality of reference signals at the first circuit; a first circuit comprising a plurality of readout elements and a plurality of photodetector readout channels representing a first portion of the plurality of signal channels and coupled to the plurality of readout elements, the plurality of readout elements configured to selectively route the plurality of reference signals to the plurality of photodetector readout channels; a second circuit comprising a plurality of processing channels representing a second portion of the plurality of signal channels, the plurality of processing channels comprising a plurality of processing elements configured to generate processed reference signals derived from a plurality of reference signals and to output the processed reference signals from the second circuit; and an evaluation circuit coupled to the signal path to receive ones of the processed reference signals, the evaluation circuit configured to compare the processed reference signals to a first expected result to generate a first comparison result.

In accordance with one or more embodiments, a method is provided for evaluating at least one characteristic of a plurality of signal channels in a time-of-flight light detection system including a plurality of circuits arranged sequentially along a time-of-flight light detection signal path including the plurality of signal channels, the plurality of circuits including a first circuit and a second circuit arranged downstream of the first circuit. The method comprises the following steps: generating a plurality of reference signals; injecting at least one of a plurality of reference signals into each of a plurality of signal channels at a first circuit such that the plurality of reference signals are processed in a signal path; comparing the processed reference signal to an expected result to generate a comparison result; evaluating at least one characteristic of at least one of the plurality of signal channels based on the comparison; and determining whether either the first circuit or the second circuit is defective based on the evaluated at least one characteristic of at least one of the plurality of signal channels.