CN114384490A - A lidar array global shutter - Google Patents

Abstract

The invention discloses a laser radar array global shutter and relates to the field of integrated circuit design. According to the global shutter of the laser radar array, when laser is emitted, the START switch is synchronously closed, the Vs voltage STARTs to integrate time from 0v to generate a ramp voltage, and then the Vs voltage is converted into the Vout voltage through the unit gain buffer, so that the Vout voltage is equal to the Vs voltage; in the initial state, the S _00-S _ mn array switches are all in a closed state, when the laser receiver detects the reflected laser, the laser receiver sends out a STOP signal and turns on the START switch, and at the moment, the corresponding voltage in the S _00-S _ mn array switches is latched and stored. The time information quantity is converted into the voltage information quantity and stored, the time information quantity is converted and read one by one in a row selection mode, and all arrays share the same time integrator, so that inconsistency errors caused by a plurality of integrators are reduced.

Description

A lidar array global shutter

technical field

The invention belongs to the field of integrated circuit design, and in particular relates to a laser radar array global shutter.

Background technique

The traditional implementation of dtof lidar is to calculate the distance between the object and the detected object by emitting laser light, reflected by the object to the receiver, and recording the time difference from the launch to the reception. Due to the fast speed of light, the amount of data for a single-point laser ranging chip is small, and a lidar receiver can easily solve the problem of data reception to conversion by receiving a time information data. For large arrays, the amount of data is large, and many lidar receivers are required to receive time information and complete the conversion, which requires a lot of circuit resources, which is quite difficult to achieve. Therefore, for large-area laser array chips, we need to solve the following problems:

(1) How to capture a large amount of time information data in a short period of time;

(2) How to store time information data;

(3) How to reduce the data conversion module;

(4) How to ensure the consistency of the data conversion module.

Therefore, in view of the above problems, it is of great significance to provide a lidar array global shutter.

SUMMARY OF THE INVENTION

The present invention provides a laser radar array global shutter, which solves the above problems.

In order to solve the above-mentioned technical problems, the present invention is achieved through the following technical solutions:

A laser radar array global shutter of the present invention includes a current mirror IS, a START switch, an integrated computing method, a C1 capacitor, and a laser receiver;

Both ends of the current mirror IS are connected to the laser receiver and the current mirror IS respectively, the current mirror IS is connected to the START switch, one end of the capacitor C1 is connected to the START switch through wiring, and the other end is grounded; The wires between the START switch and the C1 capacitor are connected, and the generated voltage is the Vs voltage; the reverse input and output terminals of the integrated arithmetic method are combined and connected, and then connected to the array switches of m columns*n rows, and the connected lines are combined and connected. The voltage generated by the segment is the Vout voltage;

The array switches of m columns*n rows are numbered using S_00-S_mn, and the corresponding voltage values on the S_00-S_mn array switches are V_00-V_mn respectively;

When the laser is emitted, the START switch is closed synchronously, the Vs voltage starts from 0v to generate a ramp voltage for the time integration, and then the unity gain buffer converts the Vs voltage to the Vout voltage, so that the Vout voltage = Vs voltage;

In the initial state, the S_00-S_mn array switches are all closed. When the laser receiver detects the reflected laser light, the corresponding laser receiver sends a STOP signal and turns on the corresponding START switch. At this time, the S_00-S_mn array switch The corresponding voltage is latched and saved, so that the time information can be converted into voltage information and saved.

The present invention includes the following beneficial effects with respect to the prior art:

The present invention converts time information into voltage information and stores it, converts and reads the time information one by one by row selection, and converts and reads row by row by column selection, so that for an array of m columns and n rows, only It needs n rows of ADC conversion, which reduces the ADC by m times; all the arrays invented share the same time integrator, which reduces the inconsistency error caused by multiple integrators.

Of course, it is not necessary for any product embodying the present invention to achieve all of the above-described advantages simultaneously.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

1 is a schematic diagram of the structural principle of a lidar array global shutter according to the present invention;

FIG. 2 is a schematic diagram of a technical solution of a conventional lidar.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

As shown in Figure 2, in the traditional scheme, one laser receiver corresponds to one TDC (time-digital-convert) to convert time information into digital, and there is no way for one TDC to accept multiple time information at the same time; therefore, m* is required for the mn array globeshutter. To complete the conversion with n TDCs, many problems such as large power consumption and large chip area will be faced in the design and manufacture.

The circuit of this technical solution realizes the storage function of time information, which can be converted and read row by row by column selection, so that for an array of m columns and n rows, only n rows of ADC conversion are required, and the ADC is reduced by m times; The array shares the same time integrator, which reduces the inconsistency error caused by multiple integrators, which is realized by the following technical means:

Please refer to FIG. 1 , a lidar array global shutter of the present invention includes a current mirror IS, a START switch, an integrated computing method, a C1 capacitor, and a laser receiver;

Both ends of the current mirror IS are connected to the laser receiver and the current mirror IS respectively, the current mirror IS is connected to the START switch, one end of the capacitor C1 is connected to the START switch through wiring, and the other end is grounded; The wires between the START switch and the C1 capacitor are connected, and the generated voltage is the Vs voltage; the reverse input and output terminals of the integrated arithmetic method are combined and connected, and then connected to the array switches of m columns*n rows, and the connected lines are combined and connected. The voltage generated by the segment is the Vout voltage;

The array switches of m columns*n rows are numbered using S_00-S_mn, and the corresponding voltage values on the S_00-S_mn array switches are V_00-V_mn respectively;

When the laser is emitted, the START switch is closed synchronously, the Vs voltage starts from 0v to generate a ramp voltage for the time integration, and then the unity gain buffer converts the Vs voltage to the Vout voltage, so that the Vout voltage = Vs voltage;

In the initial state, the S_00-S_mn array switches are all closed. When the laser receiver detects the reflected laser light, the corresponding laser receiver sends a STOP signal and turns on the corresponding START switch. At this time, the S_00-S_mn array switch The corresponding voltage is latched and saved, so that the time information can be converted into voltage information and saved.

Beneficial effects:

The present invention converts time information into voltage information and stores it, converts and reads the time information one by one by row selection, and converts and reads row by row by column selection, so that for an array of m columns and n rows, only It needs n rows of ADC conversion, which reduces the ADC by m times; all the arrays invented share the same time integrator, which reduces the inconsistency error caused by multiple integrators.

The above-disclosed preferred embodiments of the present invention are provided only to help illustrate the present invention. The preferred embodiments do not exhaust all the details, nor do they limit the invention to only the described embodiments. Obviously, many modifications and variations are possible in light of the content of this specification. The present specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is to be limited only by the claims and their full scope and equivalents.

Claims (1)

1. a lidar array global shutter, is characterized in that, comprises current mirror IS, START switch, integrated arithmetic device, C1 capacitor, laser receiver; The two ends of the current mirror IS are respectively connected with the laser receiver and the current mirror IS, the current mirror IS is connected with the START switch, one end of the C1 capacitor is connected to the START switch through wiring, and the other end is grounded; the integrated operation The forward input end of the method device is connected with the wire between the START switch and the C1 capacitor, and the voltage generated is the Vs voltage; the reverse input end and the output end of the integrated computing method device are combined and connected, and then connected to the m column * n row. The array switches, and the voltage generated by the combined and connected line segments is the Vout voltage; The array switches of m columns*n rows are numbered using S_00-S_mn, and the corresponding voltage values on the S_00-S_mn array switches are V_00-V_mn respectively; When the laser is emitted, the START switch is synchronously closed, the Vs voltage starts from 0v to generate a ramp voltage for time integration, and then the unity gain buffer converts the Vs voltage to the Vout voltage, so that the Vout voltage=Vs voltage; In the initial state, the S_00-S_mn array switches are all closed. When the laser receiver detects the reflected laser light, the corresponding laser receiver sends a STOP signal and turns on the corresponding START switch. At this time, the S_00-S_mn array switch The corresponding voltage is latched and saved, so that the time information can be converted into voltage information and saved.

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