Laser driving control system

Abstract

The invention relates to a laser driving control system, which comprises a power supply module for outputting double voltages, a power supply selection module, an FPGA module, an energy storage module, a laser, a first ITOF sensor, a second ITOF sensor and a laser driving circuit, wherein the power supply selection module is electrically connected with the dual-voltage power supply module, the FPGA module and the energy storage module respectively, the laser is electrically connected with the energy storage module and the laser driving circuit respectively, and the FPGA module is further electrically connected with the first ITOF sensor, the second ITOF sensor and the laser driving circuit respectively, so that the requirements of ITOF distance measurement and DTOF distance measurement are met at the same time.

Description

Technical Field

[0001] The present invention relates to the field of laser driving technology, and in particular to a laser driving control system. Background Art

[0002] Time of Flight (ToF) technology is a technology used to measure the time difference between the emission and return of light or other signals to calculate distance or depth information. Therefore, it is widely used in 3D imaging, robot navigation, self-driving cars, virtual reality (VR) and augmented reality (AR) and other fields.

[0003] In addition, there are two types of time-of-flight technology, namely indirect time of flight (ITOF) and direct time of flight (DTOF), which modulate the infrared light emission in different ways. Generally, ITOF and DTOF require different driving circuits for different application scenarios.

[0004] However, existing laser driving circuits are all driving circuits specifically for the ITOF mode or the DTOF mode, and their driving modes are single and cannot meet the needs of switching between near and far scenes in practical applications. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a laser drive control system to meet the needs of scene switching in practical applications.

[0007] (II) Technical solution

[0008] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0009] An embodiment of the present invention provides a laser drive control system, comprising a dual voltage power supply module, a power selection module, an FPGA module, an energy storage module, a laser, a first ITOF sensor, a second ITOF sensor and a laser drive circuit; wherein the power selection module is electrically connected to the dual voltage power supply module, the FPGA module and the energy storage module respectively, and the laser is electrically connected to the energy storage module and the laser drive circuit respectively, and the FPGA module is also electrically connected to the first ITOF sensor, the second ITOF sensor and the laser drive circuit respectively;

[0010] The FPGA module is used to send a SYNC signal to one of the first ITOF sensor and the second ITOF sensor in a time-sharing manner, and receive a STROBE signal and a LVDS signal sent by one of the sensors, and control the power selection module to select a voltage corresponding to the frequency of the LVDS signal to power the energy storage module, and control the energy storage module to discharge during exposure, and when one of the sensors is idle, superimpose the DTOF signal on the LVDS signal to obtain a superimposed signal, and when the exposure time reaching one of the sensors is determined by the STROBE signal, send the superimposed signal to the laser driving circuit so that the laser driving circuit processes the superimposed signal, and control the laser to output laser based on the processed signal.

[0011] In a possible embodiment, the laser drive control system further includes: a discharge control module, the discharge control module is electrically connected to the power selection module, the FPGA module and the energy storage module respectively, and the discharge control module is used to discharge under the control of the FPGA module when switching from high voltage to low voltage.

[0012] In a possible embodiment, the laser driving control system further includes: a current limiting protection module, which is electrically connected to the energy storage module, the laser and the laser driving circuit respectively, and is used to perform current limiting protection on the laser driving circuit.

[0013] In a possible embodiment, the laser driving circuit includes: a differential to single-ended module, the differential to single-ended module is electrically connected to the FPGA module, and the differential to single-ended module is used to convert the superimposed signal into a single-ended signal.

[0014] In a possible embodiment, the laser driving circuit further includes: a high-frequency driving module, the high-frequency driving module is electrically connected to the differential-to-single-ended module, and the high-frequency driving module is used to shape the single-ended signal and increase the driving capability.

[0015] In a possible embodiment, the laser driving circuit further includes: a high-frequency MOS module, which is electrically connected to the high-frequency driving module and the laser, respectively, and is used to provide a low-impedance and high-current loop for high-frequency modulation lighting of the laser.

[0016] In a possible embodiment, the laser driving circuit further includes: an absorption module, the absorption module is electrically connected to the high-frequency MOS module and the laser, respectively, and the absorption module is used to absorb the overshoot signal.

[0017] In a possible embodiment, the energy storage module and the high-frequency MOS module are both connected to the power ground.

[0018] (III) Beneficial effects

[0019] The beneficial effects of the present invention are:

[0020] The embodiment of the present invention proposes a laser drive control system, which is compatible with two types of TOF ranging laser drive control schemes and circuit implementation methods, and can simultaneously meet the requirements of ITOF 30m ranging and DTOF 50m ranging.

[0021] In order to make the above-mentioned objectives, features and advantages to be achieved by the embodiments of the present application more obvious and understandable, the following specifically cites preferred embodiments and describes them in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A schematic diagram of the structure of an ITOF in the prior art is shown;

[0024] Figure 2 A structural schematic diagram of a DTOF in the prior art is shown;

[0025] Figure 3 A structural block diagram of an overall system solution provided by an embodiment of the present application is shown;

[0026] Figure 4 A schematic diagram of a laser driving control system provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0027] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0028] Currently, there is no product on the market that combines ITOF and DTOF, and the distance measurement of ITOF products is generally between 0.1 and 6 meters, rarely exceeding 10 meters, and the horizontal field of view is also small. In addition, in obstacle avoidance scenarios, ITOF is difficult to solve the problem of multi-machine interference.

[0029] And, if Figure 1 and Figure 2As shown in the figure, the ITOF currently on the market has the characteristics of low power supply voltage, wide modulation frequency range (3MHz~200MHz), long exposure time, low laser power and short distance measurement, while the DTOF has the characteristics of high power supply voltage, low repetition rate (≤2MHz), high laser peak power and long distance measurement. Therefore, these two TOFs are very different in terms of laser drive circuit, control method, power supply circuit, laser selection, and specific implementation, and cannot be compatible at the same time.

[0030] Based on this, an embodiment of the present invention proposes a laser drive control system, which is compatible with two types of TOF ranging laser drive control schemes and circuit implementation methods, and can simultaneously meet the requirements of ITOF 30m ranging and DTOF 50m ranging.

[0031] It should be understood that the name of the present application may also be referred to as a laser drive system, etc.

[0032] In order to better understand the above technical solution, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0033] See also Figure 3 , Figure 3 FIG. 1 shows a structural block diagram of an overall system solution provided by an embodiment of the present application. Figure 3 As shown, the overall system solution includes an FPGA module, a laser emission module, a collimating lens, a light homogenizer, two ITOF sensors (i.e., ITOF SENSOR1 and ITOF SENSOR2), two optical lenses (i.e., optical lens 1 and optical lens 2), a SIPM and a focusing lens.

[0034] Among them, the FPGA module is mainly responsible for the logic timing required for operation, such as the control of the laser generation module, the control of peripheral devices, the register configuration of the ITOF SENSOR, the reception and processing of MIPI data, the image algorithm, the interaction with the host computer, etc.

[0035] The laser emission module mainly includes the power supply of the laser driving circuit, signal processing, high-frequency MOS driving and protection circuit and energy storage circuit, etc.

[0036] The collimating lens is used to compress the laser divergence angle into a point light source;

[0037] The light diffuser turns the point light source into a flood light source with a larger angle;

[0038] Both optical lenses are used to project the reflected signal of the target object onto the corresponding ITOF sensor after passing through the filter;

[0039] The ITOF sensor is used to image the reflection signal of the target object and output it through the mipi interface;

[0040] The focusing lens is used to focus the reflected signal of the target object onto the SIPM sensor;

[0041] SIPM, as a receiving sensor of DTOF, is used to receive the transmitted signal of the target object and image the reflected signal of the target object. It is mainly used to assist in solving multi-machine interference, cycle flipping, etc.

[0042] In order to facilitate understanding of the specific structural diagram of the laser emission module, FPGA module and 2-way ITOF sensor of the present application, a description is given below through specific embodiments.

[0043] See also Figure 4 , Figure 4 FIG. 1 is a schematic diagram of a laser drive control system provided by an embodiment of the present application. Figure 4 As shown, the laser drive control system includes a dual voltage power supply module, a power supply selection module, an FPGA module, a discharge control module, a current limiting protection module, an energy storage module, a laser, a laser protection module, a first ITOF sensor (i.e., ITOFSENSOR1), a second ITOF sensor (i.e., ITOF SENSOR2) and a laser drive circuit.

[0044] Among them, the power selection module is electrically connected to the dual voltage power supply module, the FPGA module, the discharge control module and the current limiting protection module, and the current limiting protection module is also electrically connected to the energy storage module, the laser and the laser protection module, and the laser is also electrically connected to the laser driving circuit, and the FPGA module is also electrically connected to the first ITOF sensor, the second ITOF sensor and the laser driving circuit.

[0045] And, continue to see Figure 4 The laser driving circuit includes a differential-to-single-ended module, a high-frequency driving module and a high-frequency MOS module connected in sequence, and the differential-to-single-ended module is also connected to the FPGA module, and the high-frequency MOS module is connected to the laser, and the laser driving circuit further includes an absorption module, and the absorption module is electrically connected to the high-frequency MOS module, the laser and the laser protection module respectively.

[0046] Among them, the dual voltage power supply module can provide 2 kinds of voltages for the laser driving circuit, which is used to power the 3 frequencies of the ITOF. Different frequencies correspond to different power supply voltages, high frequency uses high voltage, and medium and low frequencies use low voltage. It should be noted here that the specific frequency of the high frequency, the specific frequency of the medium frequency and the specific frequency of the low frequency can be set according to actual needs, and the embodiments of the present application are not limited to this;

[0047] A power selection module, and the power selection module is controlled by the FPGA module, and the FPGA module can select different power supply voltages according to different frequencies. In addition, the laser drive circuit has two voltage options, one high voltage and one low voltage, which are controlled by the FPGA module;

[0048] The discharge control module is controlled by the FPGA module, and the FPGA selects different power supply voltages according to different frequencies, especially when the high voltage is switched to the low voltage, the FPGA needs to control the discharge circuit to discharge. That is to say, the FPGA controls the power supply selection module to select voltages corresponding to different frequencies for the first ITOF sensor and the second ITOF sensor, and when the high voltage is to be switched to the low voltage, the FPGA controls the discharge control module to discharge. Since the exposure interval of each frequency is relatively short, the discharge time needs to be strictly controlled to discharge the voltage to the required value, otherwise it will not discharge or the discharge is insufficient and directly switch to a different frequency, which may damage the laser;

[0049] The current limiting protection module is used to protect the drive circuit from overcurrent damage;

[0050] The laser protection module is used to provide reverse voltage protection;

[0051] The energy storage module is used to discharge during exposure, and due to the different frequencies (especially low frequencies) and long exposure time of ITOF, a suitable energy storage capacitor is required. In other words, after the supply voltage passes through the current limiting resistor, a larger energy storage capacitor is required (the ITOF exposure time is very long, up to nearly 1ms) to ensure that the laser can work normally during ITOF exposure or DTOF exposure;

[0052] The differential to single-ended module is used to convert the two LVDS signals output by the two TOF sensors into one LVDS signal after superimposing the DTOF signal through the FPGA, and then converting it into a single-ended signal after passing through the differential to single-ended module;

[0053] The high-frequency drive module is used to shape the single-ended signal and increase the drive capability;

[0054] The high-frequency MOS is used to provide a low-impedance and high-current loop for high-frequency modulation of the laser, and the specific current loop of the low-impedance and high-current loop can be set according to actual needs, and the embodiments of the present application are not limited thereto;

[0055] The absorption module is used to absorb overshoot signals;

[0056] The first ITOF sensor and the second ITOF sensor have three different frequencies, each with a different exposure time, which is controlled by the FPGA module. The frequency and voltage correspond to each other: the first frequency corresponds to high voltage, which is used for long-distance measurement; the second and third frequencies correspond to low voltage, which are used for close-range measurement and anti-rollover cycle. The first frequency is higher than the second frequency, and the second frequency is higher than the third frequency.

[0057] Based on the above-mentioned device, the FPGA module is used to send a SYNC signal to one of the first ITOF sensor and the second ITOF sensor in a time-sharing manner (for example, sending a SYNC1 signal to the first ITOF sensor at the first time, and sending a SYNC2 signal to the second ITOF sensor at the second time), and receive a STROBE signal and a LVDS signal sent by one of the sensors. For example, after sending a SYNC1 signal to the first ITOF sensor, the STROBE1 signal and the LVDS1 signal sent by the first ITOF sensor are received; for another example, when sending a SYNC2 signal to the second ITOF sensor, the STROBE2 signal and the LVDS2 signal sent by the second ITOF sensor are received. And, when the ITOF sensor that needs to be exposed later is idle (i.e., not exposed), the FPGA module superimposes the DTOF signal on the LVDS signal corresponding to the ITOF sensor that needs to be exposed later to obtain the superimposed signal. Furthermore, when it is determined through the STROBE signal corresponding to the ITOF sensor that needs to be exposed subsequently that the exposure time has been reached, the superimposed signal is sent to the laser driving circuit so that the laser driving circuit processes the superimposed signal and controls the laser to output laser based on the processed signal.

[0058] Furthermore, the first ITOF sensor, the second ITOF sensor and the DTOF sensor receive the echo signal of the target object, perform image algorithm processing, and output intensity, depth map and point cloud map.

[0059] It should be noted here that the scanning range of the first ITOF sensor and the scanning range of the second ITOF sensor have an overlapping range, and the first ITOF sensor and the second ITOF sensor work at different times, so the STROBE signal and LVDS signal fed back are also fed back at different time periods.

[0060] It should be understood that the specific method of superimposing the DTOF signal on the LVDS signal can be set according to actual needs, and the embodiments of the present application are not limited thereto.

[0061] It should also be noted here that the FPGA module can also control the closing or opening of the differential to single-ended module, so that when the ITOF sensor is exposed, the differential to single-ended module is controlled to be turned on, and when the exposure of the ITOF sensor is finished, the differential to single-ended module is controlled to be turned off, thereby avoiding the situation where the differential to single-ended module receives an erroneous signal and causes circuit damage.

[0062] In order to facilitate understanding of the embodiments of the present application, a description is given below using specific embodiments.

[0063] Specifically, at the first time, the FPGA module sends a SYNC1 signal to the first ITOF sensor, and receives a STROBE1 signal and a LVDS1 signal fed back by the first ITOF sensor. Also, when the first ITOF sensor is determined to be idle through the STROBE1 signal, the DTOF signal is superimposed on the LVDS1 signal to obtain a superimposed signal, and then when it is determined through the STROBE1 signal that the exposure time of the first ITOF sensor has been reached, the superimposed signal is sent to the laser driving circuit so that the laser driving circuit processes the superimposed signal, and the laser is controlled to output laser light based on the processed signal.

[0064] Subsequently, when the second time is reached, the FPGA module sends a SYNC2 signal to the second ITOF sensor, and receives a STROBE2 signal and a LVDS2 signal fed back by the second ITOF sensor. Also, when the second ITOF sensor is determined to be idle through the STROBE2 signal, the DTOF signal is superimposed on the LVDS2 signal to obtain a superimposed signal, and then when it is determined through the STROBE2 signal that the exposure time of the second ITOF sensor has been reached, the superimposed signal is sent to the laser driving circuit so that the laser driving circuit processes the superimposed signal, and the laser is controlled to output laser light based on the processed signal.

[0065] Therefore, with the help of the above technical solution, the present application can be compatible with two types of TOF ranging laser drive control solutions and circuit implementation methods, and can simultaneously meet the needs of ITOF 30m ranging and DTOF 50m ranging.

[0066] Furthermore, it helps in miniaturization of the product and can be adapted to more application scenarios.

[0067] It should be understood that the above-mentioned laser driving control system is only exemplary, and those skilled in the art may make various modifications based on the above-mentioned method, and the modified scheme also falls within the protection scope of the present application.

[0068] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0069] The present invention is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to the embodiments of the present invention. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions.

[0070] It should be noted that in the claims, any reference numerals placed between brackets shall not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The invention may be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In the claims enumerating several means, several of these means may be embodied by the same hardware. The use of the words first, second, third, etc., is for convenience of expression only and does not indicate any order. These words may be understood as part of the component name.

[0071] In addition, it should be noted that, in the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0072] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments after knowing the basic creative concept. Therefore, the claims should be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0073] Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention should also include these modifications and variations.

Claims

1. A laser drive control system, characterized in that: It includes a dual voltage power supply module, a power selection module, an FPGA module, an energy storage module, a laser, a first ITOF sensor, a second ITOF sensor and a laser driving circuit; wherein the power selection module is electrically connected to the dual voltage power supply module, the FPGA module and the energy storage module respectively, and the laser is electrically connected to the energy storage module and the laser driving circuit respectively, and the FPGA module is also electrically connected to the first ITOF sensor, the second ITOF sensor and the laser driving circuit respectively; The FPGA module is used to send a SYNC signal to one of the first ITOF sensor and the second ITOF sensor in a time-sharing manner, and receive a STROBE signal and a LVDS signal sent by one of the sensors, and control the power selection module to select a voltage corresponding to the frequency of the LVDS signal to power the energy storage module, and control the energy storage module to discharge during exposure, and when one of the sensors is idle, superimpose a DTOF signal on the LVDS signal to obtain a superimposed signal, and when the exposure time reaching one of the sensors is determined by the STROBE signal, send the superimposed signal to the laser driving circuit so that the laser driving circuit processes the superimposed signal, and control the laser to output laser based on the processed signal.

2. The laser drive control system according to claim 1, characterized in that: The laser drive control system further comprises: A discharge control module, wherein the discharge control module is electrically connected to the power selection module, the FPGA module and the energy storage module respectively, and is used for discharging under the control of the FPGA module when the high voltage is switched to the low voltage.

3. The laser drive control system according to claim 2, characterized in that: The laser drive control system further comprises: A current limiting protection module is electrically connected to the energy storage module, the laser and the laser driving circuit respectively, and is used for performing current limiting protection on the laser driving circuit.

4. The laser drive control system according to claim 3, characterized in that: The laser driving circuit comprises: A differential to single-ended module is electrically connected to the FPGA module, and is used to convert the superimposed signal into a single-ended signal.

5. The laser drive control system according to claim 4, characterized in that: The laser driving circuit further comprises: A high-frequency driving module is electrically connected to the differential-to-single-ended module, and is used to shape the single-ended signal and increase the driving capability.

6. The laser drive control system according to claim 5, characterized in that: The laser driving circuit further comprises: A high-frequency MOS module is electrically connected to the high-frequency driving module and the laser, respectively, and is used to provide a low-impedance and high-current loop for high-frequency modulation and lighting of the laser.

7. The laser drive control system according to claim 6, characterized in that: The laser driving circuit further comprises: An absorption module is electrically connected to the high-frequency MOS module and the laser respectively, and is used to absorb overshoot signals.

8. The laser drive control system according to claim 6, characterized in that: The energy storage module and the high-frequency MOS module are both connected to a power ground.

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