Constant-current transmitting circuit and laser radar

Abstract

The embodiment of the invention discloses a constant-current transmitting circuit and a laser radar. The constant-current transmitting circuit comprises a constant-current power adjustable module and a constant-voltage transmitting module. The constant-current power adjustable module comprises an energy storage element, the input end of the constant-current power adjustable module is used for being connected with a transmitting power supply outputting power supply voltage so as to charge the energy storage element through the power supply voltage, and the constant-current power adjustable module is used for providing constant current for the energy storage element and adjusting the energy stored by the energy storage element; the constant-voltage transmitting module comprises a laser, the laser is connected with the energy storage element, the laser is used for transmitting laser when the energy storage element releases energy, and different energies stored in the energy storage element correspond to different laser transmitting powers. The constant-current transmitting circuit can provide constant current for the energy storage element, the problem that the laser emits light by mistake is avoided, and the reliability and accuracy of laser emitted by the laser are guaranteed.

Description

Technical Field

[0001] The present application relates to the field of laser radar technology, and in particular to a constant current transmitting circuit and a laser radar. Background Art

[0002] In the related art, a switch control module is provided between the constant voltage transmitting power supply and the laser to adjust the driving voltage provided by the constant voltage transmitting power supply to the laser through the switch control module. However, when the constant voltage transmitting power supply is charged, the charging current is infinite, and the charging current may be greater than the current threshold required for the laser to emit light, causing the laser to emit light by mistake. Summary of the invention

[0003] The embodiments of the present application provide a constant current transmitting circuit and a laser radar. The constant current transmitting circuit can provide a constant current for an energy storage element, thereby avoiding the problem of mis-lighting of the laser and ensuring the reliability and accuracy of the laser emitted by the laser.

[0004] In the first aspect, an embodiment of the present application provides a constant current transmitting circuit, including a constant current power adjustable module and a constant voltage transmitting module; the constant current power adjustable module includes an energy storage element, and the input end of the constant current power adjustable module is used to connect to a transmitting power supply with an output power supply voltage to charge the energy storage element through the power supply voltage, and the constant current power adjustable module is used to provide a constant current to the energy storage element and adjust the amount of energy stored in the energy storage element; the constant voltage transmitting module includes a laser, the laser is connected to the energy storage element, and the laser is used to emit a laser when the energy storage element releases energy, and different energies stored in the energy storage element correspond to different laser emission powers.

[0005] Based on the constant current power adjustable module provided in the embodiment of the present application, it is provided with an energy storage element, a first control circuit and a second control circuit. By controlling the conduction state and conduction time of the first control circuit and the second control circuit, the constant current transmitting circuit can enable the laser to emit lasers of different powers based on the power supply voltage. The charging current flowing into the energy storage element can be made constant current through the first control circuit, thereby ensuring the current stability connected to the energy storage element, thereby avoiding the problem that the laser connected in parallel with the energy storage element is damaged by a large current shock and the laser emits light by mistake, and ensuring the reliability of the laser emitted by the constant current transmitting circuit. Moreover, the switching response speed of the second control circuit is fast, which ensures the overall reliability of the constant current transmitting circuit, so as to be suitable for different laser radars and detection scenarios. The constant current transmitting circuit in the present application does not need to set up additional charging elements and boost circuits, the overall structure is simple, and there is no boost process in the constant current transmitting circuit, and the energy loss is low.

[0006] In one possible design, the constant current power adjustable module also includes: a first control circuit and a second control circuit; one end of the first control circuit is connected to the transmitting power supply, and the other end is connected to the energy storage element; one end of the second control circuit is connected to the second end of the energy storage element, and the other end is grounded; wherein, when the energy storage element is charged, the first control circuit and the second control circuit are both turned on and the on-time is controllable, so as to charge the energy storage element through the transmitting power supply and control the amount of energy stored in the energy storage element, and the current flowing through the first control circuit and into the energy storage element is a constant current; when the energy storage element releases energy, at least the first control circuit is turned off.

[0007] Based on the above optional method, the current flowing through the first control circuit and into the energy storage element can be made constant through the first control circuit. In this way, the constant current power adjustable module can not only make the charging current in the charging stage constant current to avoid the problem of damage to the energy storage element, but also adjust the amount of energy stored in the energy storage element, thereby ensuring the reliability and accuracy of the laser emitted by the laser, and further ensuring the detection reliability and accuracy of the laser radar using the constant current transmitting circuit.

[0008] In a possible design, the first control circuit includes: a first high-side switch, the drain of the first high-side switch is used to connect to the transmitting power supply, the source is connected to the first end of the energy storage element, and the controlled end is used to access the power control signal.

[0009] Based on the above optional method, there is a large voltage difference between the energy storage element and the transmitting power supply, so that the first high-side switch operates in the saturation zone. In this way, the current flowing through the first high-side switch and flowing to the energy storage element is a constant current, which ensures the reliability of the laser during the charging stage.

[0010] In a possible design, the first control circuit includes: a first switch, and the first switch is connected in series between a transmitting power source and a first end of an energy storage element.

[0011] Based on the above optional manner, the charging state of the energy storage element and the amount of energy stored in the energy storage element can be accurately controlled by controlling the conduction state and conduction time of the first switch, thereby ensuring the reliability of laser emission.

[0012] In one possible design, the second control circuit includes: a first low-side switch and a second low-side switch; the drain of the first low-side switch is connected to the second end of the energy storage element, and the controlled end is used to access the energy storage control signal; the drain of the second low-side switch is grounded, the source is connected to the source of the first low-side switch, and the controlled end is used to access the energy storage control signal.

[0013] Based on the above optional manner, the first low-side switch and the second low-side switch can realize rapid on and off control of the ground conduction loop of the energy storage element when the energy storage element releases energy, thereby accurately controlling the charging energy of the energy storage element.

[0014] In a possible design, the second control circuit includes: a diode, an anode of the diode is connected to the second end of the energy storage element, and a cathode of the diode is grounded.

[0015] Based on the above optional method, the diode plays a role of voltage stabilization and protection to ensure the stability of the constant current power adjustable module. In addition, in the charging stage, the diode is turned on to charge the energy storage element. When the diode is turned off, the charging circuit is disconnected to achieve precise control of the charging energy of the energy storage element. In the energy release stage, the energy released by the energy storage element flows into the anode of the laser and flows out from the cathode of the laser. At this time, since the characteristic of the diode is unidirectional conductivity, the current flowing out of the cathode of the laser will flow into the second end of the energy storage element to form an energy release circuit, thereby ensuring the energy release reliability in the energy release stage.

[0016] In a possible design, the laser includes: a laser diode, an anode of the laser diode is grounded, and a cathode is respectively connected to an anode of the first diode and a second end of the energy storage element.

[0017] In a possible design, the second control circuit includes: a second switch connected in series between the second end of the energy storage element and the ground end.

[0018] In one possible design, the constant voltage emission module also includes: an emission control switch, the source of the emission control switch is connected to the anode of the laser, the drain is connected to the first end of the energy storage element, the controlled end is used to receive the emission control signal, and the cathode of the laser is connected to the second end of the energy storage element; wherein, when the energy storage element is charged, the emission control switch is turned off, and when the energy storage element is released, the emission control switch is turned on.

[0019] In the second aspect, an embodiment of the present application provides a laser radar, comprising: a constant current transmitting circuit, a controller and a laser receiving circuit as described in any optional manner in the first aspect; the controller is connected to a constant current power adjustable module and a constant voltage transmitting module; the laser receiving circuit is connected to the controller, and is used to receive the echo light formed by the laser emitted by the constant current transmitting circuit being reflected by a target object.

[0020] In one possible design, the laser radar also includes: a laser array, the laser array is composed of M*N lasers, M and N are respectively the number of rows and columns of lasers included in the laser array, M and N are both positive integers, and at least one of M and N is greater than or equal to 2.

[0021] Based on the above optional methods, the laser radar provided in the embodiment of the present application can be a combination of one laser corresponding to one constant current power adjustable module, or a combination of a laser array composed of multiple lasers corresponding to one constant current power adjustable module, or a combination of a laser array composed of multiple lasers corresponding to multiple constant current power adjustable modules. Based on different combinations, the laser radar provided in the present application can also achieve different effects. Moreover, the constant current power adjustable module is not provided with charging devices such as inductors, so there is no difference between inductors, thereby avoiding the problem of poor consistency of the laser emitted by the laser radar as a whole, and even if there are multiple constant current power adjustable modules and lasers in the laser radar provided in the embodiment of the present application, the heat generated by the overall circuit is also small, and the circuit loss is also low.

[0022] Based on the constant voltage transmitting circuit and laser radar provided in the embodiments of the present application, the constant voltage transmitting circuit can emit lasers of different powers based on the power supply voltage, and can also ensure that the charging current flowing into the energy storage element during the charging stage is a constant current, thereby ensuring the overall reliability of the constant voltage transmitting circuit, and further ensuring the detection reliability of the laser radar using the constant current transmitting circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 It is a circuit diagram of a low-voltage transmitting circuit in the related art;

[0025] Figure 2 It is a circuit diagram of another constant voltage transmitting circuit in the related art;

[0026] Figure 3 It is a schematic diagram of the framework structure of a laser radar provided in an embodiment of the present application;

[0027] Figure 4 This is a schematic diagram of the framework structure of another laser radar provided in an embodiment of the present application;

[0028] Figure 5 It is a schematic diagram of the framework structure of a constant current transmitting circuit provided in an embodiment of the present application;

[0029] Figure 6 It is a schematic diagram of the framework structure of another constant current transmitting circuit provided in an embodiment of the present application;

[0030] Figure 7 1 is a circuit structure diagram of a constant current transmitting circuit provided in an embodiment of the present application;

[0031] Figure 8 It is a circuit structure diagram of another constant current transmitting circuit provided in an embodiment of the present application;

[0032] Fig. 9 is a circuit structure diagram of another constant current transmitting circuit provided in an embodiment of the present application;

[0033] Fig.10 It is a circuit structure schematic diagram of another constant current transmitting circuit provided in an embodiment of the present application;

[0034] Fig.11 It is a circuit structure schematic diagram of another constant current transmitting circuit provided in an embodiment of the present application;

[0035] Fig.12 It is a circuit structure schematic diagram of another constant current transmitting circuit provided in an embodiment of the present application;

[0036] Fig.13 It is a circuit structure schematic diagram of another constant current transmitting circuit provided in an embodiment of the present application.

[0037] Reference numerals:

[0038] 1-laser radar; 11-constant current transmitting circuit; 111-constant current power adjustable module; 1111-energy storage element; 1112-first control circuit; 1113-second control circuit; 112-constant voltage transmitting module; 1121-laser; 12-controller; 13-laser receiving circuit;

[0039] V1- low voltage transmitting power supply; V2- constant voltage transmitting power supply; V3- transmitting power supply; L- inductor; Q1- first switching element; Q2- second switching element; Q3- first high side switch; Q4- third low side switch; Q5- second high side switch; Q6- first low side switch; Q7- second low side switch; Q8- transmitting control switch; D1- rectifier diode; D2- diode; D3- laser diode; C1- capacitor; C2- energy storage capacitor. DETAILED DESCRIPTION

[0040] In order to make the objectives, technical solutions and advantages of the present application more clear, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0041] When the following description refers to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Instead, they are only examples of devices and methods consistent with some aspects of the present application as detailed in the attached embodiments.

[0042] In the description of the present application, it should be understood that the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances. In addition, in the description of the present application, unless otherwise specified, "multiple" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects associated before and after are in an "or" relationship.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0044] At present, LiDAR technology is becoming more and more mature, and is widely used in various fields such as distance measurement, mapping, traffic management, and atmospheric monitoring. LiDAR is usually composed of a laser transmitter and a laser detector, in which the laser transmitter is used to emit laser light to the target object in the detection area, and the laser detector is used to receive the echo light generated by the reflection of the laser from the target object in the detection area. The LiDAR can complete the detection of the LiDAR based on the distance and speed of the target object of the echo light. In order to enable the laser transmitter to be stimulated to emit laser light, it is usually necessary to provide the laser transmitter with a driving current of the required intensity to ensure that it can be stimulated to emit laser light based on the driving current.

[0045] In the related art, a low voltage transmitting power supply or a constant voltage transmitting power supply is usually used to provide a driving voltage for the laser. For example, see Figure 1 , which is a circuit for providing driving current for the laser and a driving regulation circuit for energy control in the related art. The driving circuit is usually composed of an inductor (such as Figure 1 As shown in L), the first switch element (as Figure 1 As shown in Q1), rectifier diode (such as Figure 1 D1) and capacitors (as shown Figure 1 One end of the inductor L is connected to a low voltage transmitting power supply (such as Figure 1 As shown in V1), the other end of the inductor L is connected to the drain of the first switch element Q1, the source of the first switch element Q1 is connected to one end of the rectifier diode D1, the controlled end of the first switch element Q1 is used to access the emission control signal, the other end of the rectifier diode D1 is connected to the first plate of the capacitor C1 and the input end of the laser transmitter, and the second plate of the capacitor C1 is grounded. When the first switch element Q1 is turned on, the current provided by the low-voltage transmission power supply V1 charges the inductor L; when the first switch element Q1 is turned off, the current on the inductor L charges the capacitor C1 through the rectifier diode D1; when the capacitor C1 is fully charged, it will discharge to the input end of the laser transmitter. Here, it is worth noting that the discharge of the capacitor C1 provides a driving current for the laser transmitter, so that the laser transmitter can be stimulated to emit a laser based on the driving current. The driving regulation circuit is a boost circuit. In the process of converting low voltage to high voltage, due to the inductor L, there is a certain loss in the inductor L during the actual boost process, resulting in a certain energy loss in the laser transmitter. At the same time, the laser radar may be connected to other peripheral circuits. Since it is equipped with the inductor L, a large cable is required to transmit a large current, so there is a problem of cable loss. In addition, the inductor L and the first switching element Q1 occupy a large area, and the heat generated during use is large, which increases the area and heat dissipation cost, which is not conducive to integrated design.

[0046] Here, it can be understood that when multiple driving and adjusting circuits are provided in the laser radar to drive multiple laser groups, the laser radar is too large, and because there are certain differences between the inductances L, it will affect the power of the output lasers of the multiple lasers, resulting in poor uniformity of the laser emitted by the laser radar and poor actual detection effect.

[0047] For example, see Figure 2 , Figure 2 The constant voltage transmitting power supply is used to provide a driving voltage for the laser. The driving circuit is composed of a second switching element (such as Figure 2 Q2) as shown, the drain of the second switch element Q2 is connected to a constant voltage transmitting power supply (as shown Figure 2As shown in V2), the source of the second switch element Q2 is connected to the input end of the laser transmitter, and the controlled end of the second switch element Q2 is used to access the emission control signal, and the on-off state and the conduction time of the second switch element Q2 are controlled by the emission control signal, so as to control the light-emitting state of the laser and the power of the emitted laser. However, when charging by the constant voltage transmitting power supply V2, the charging current is infinite, and there may be a charging current greater than the current threshold required for the laser to emit light, so that the laser has the problem of false light emission. In order to avoid this problem, it is usually necessary to set a current limiting resistor to limit the charging current, so that the power consumption of the driving circuit is increased while the charging efficiency is reduced, and the volume of the driving circuit is increased. Moreover, in the laser radar using the constant voltage transmitting power supply V2 in the related art, it is usually necessary to release the high voltage and convert the low voltage to charge, and there are many parasitic capacitors and inductors in the laser transmitter, which leads to the slow process of releasing the high voltage and charging the low voltage, thereby affecting the frequency of the laser radar emitting laser.

[0048] To this end, the present application provides a constant current transmitting circuit and a laser radar, which can provide a constant current to the energy storage element without adding additional devices, thereby avoiding the problem of excessive charging current causing the laser to emit false light, and ensuring the reliability and accuracy of the laser output.

[0049] The constant current transmitting circuit and laser radar provided in the present application are exemplarily introduced below in conjunction with the accompanying drawings.

[0050] See also Figure 3 The embodiment of the present application is a laser radar 1, which may include a constant current transmitting circuit 11, a controller 12 and a laser receiving circuit 13. The controller 12 is connected to the constant current transmitting circuit 11 and the laser receiving circuit 13. The controller 12 is used to control the constant current transmitting circuit 11 to emit light upon stimulation, and to control the laser receiving circuit 13 to receive the echo light formed by the laser emitted by the constant current transmitting circuit 11 being reflected by the target object, so as to determine the distance and speed of the target object and complete the detection of the target object.

[0051] In one example, see Figure 4 The constant current transmitting circuit 11 may include a constant current power adjustable module 111 and a constant voltage transmitting module 112. The input end of the constant current power adjustable module 111 is connected to a transmitting power source (such as Figure 4V3) is connected to receive the power supply voltage provided by the transmitting power supply V3. The constant current power adjustable module 111 can also adjust the power of the laser emitted by the constant voltage transmitting module 112 based on the power supply voltage. In this way, the constant current transmitting circuit 11 provided in the embodiment of the present application can emit lasers of different powers based on the power supply voltage, so that the laser radar 1 can detect target objects in a wider range and at different distances, thereby widening the detection range of the constant current transmitting circuit 11.

[0052] For example, see Figure 5 , the constant current power adjustable module 111 may include an energy storage element 1111, the constant current power adjustable module 111 is used to provide a constant current for the energy storage element 1111, the constant voltage emission module 112 may include a laser 1121, and the constant current power adjustable module 111 includes at least two stages, namely, the energy storage element 1111 charging stage and the energy storage element 1111 releasing stage. The energy storage element 1111 charging stage includes charging the energy storage element 1111 with a power supply voltage, and the energy storage element 1111 releasing stage includes releasing the electric energy stored in the energy storage element 1111 to drive the laser 1121 to emit laser, so as to complete the stimulated light emission step. In order to avoid the problem of excessive charging current during the charging process, which may cause the laser 1121 to emit light by mistake, when the power supply voltage charges the energy storage element 1111, the current flowing into the energy storage element 1111 is a constant current. In this way, the charging current is stable, which avoids the problem of excessive charging current during the charging process, which may cause the laser 1121 to emit light by mistake, and ensures the reliability and accuracy of the laser emitted by the laser 1121. In addition, the constant current power adjustable module 111 can adjust the amount of energy stored in the energy storage element 1111. Here, it can be understood that by adjusting the amount of energy stored in the energy storage element 1111, the laser 1121 can emit lasers of different powers. In this way, the constant current emission circuit 11 provided in the embodiment of the present application can emit lasers of different powers based on constant high voltage, thereby achieving the effect of detecting target objects of different distances in a wider range.

[0053] Here, it is worth noting that in the embodiment of the present application, the power supply voltage provided by the transmitting power supply V3 connected to the constant current power adjustable module 111 can be a constant voltage or a non-constant voltage. The present application only needs to make the charging current in the charging stage a constant current through the constant current power adjustable module 111. This application does not make any specific restrictions on this.

[0054] Since the energy storage element 1111 generates strong reverse current fluctuations at both ends during the charging process, it is connected in parallel with the laser 1121 in the constant current transmitting module 112, and there may be a reverse current flowing to the laser 1121, causing the laser 1121 to be damaged by a large current shock. In order to make the charging current in the charging stage a constant current, and also to accurately adjust and control the energy stored in the energy storage element 1111 to ensure the reliability of the laser 1121 emitting the laser. In one example, the constant current power adjustable module 111 also includes: a first control circuit 1112 and a second control circuit 1113, one end of the first control circuit 1112 is connected to the transmitting power supply V3, the other end of the first control circuit 1112 is connected to the energy storage element 1111, one end of the second control circuit 1113 is connected to the second end of the energy storage element 1111, and the other end of the second control circuit 1113 is grounded. The charging state of the energy storage element 1111 and the amount of energy stored in the energy storage element 1111 by the transmitting power source V3 can be controlled by controlling the conduction state and conduction time of the first control circuit 1112 and the second control circuit 1113, and the current flowing through the first control circuit 1112 and into the energy storage element 1111 can be made constant current through the first control circuit 1112. In this way, the constant current power adjustable module 111 provided in the embodiment of the present application can not only make the charging current in the charging stage a constant current to avoid the problem of damage to the energy storage element, but also can adjust the amount of energy stored in the energy storage element 1111, thereby ensuring the reliability and accuracy of the laser emitted by the laser 1121, and further ensuring the detection reliability and accuracy of the laser radar 1 using the constant current transmitting circuit 11.

[0055] Exemplarily, in the charging stage of the energy storage element 1111, the first control circuit 1112 and the second control circuit 1113 are both turned on, and the current corresponding to the power supply voltage provided by the transmitting power supply V3 passes through the first control circuit 1112, the energy storage element 1111 and the second control circuit 1113 to the ground in turn, forming a charging loop. At this time, the first control circuit 1112 can make the current flowing through the first control circuit 1112 and into the energy storage element 1111 a constant current, ensuring the stability of the current connected to the energy storage element 1111, thereby avoiding the problem that the laser 1121 connected in parallel with the energy storage element 1111 is damaged by a large current shock. At the same time, it also avoids the problem that when charging the energy storage element 1111, the charging current is infinite, resulting in the charging current being greater than the current threshold required for the laser 1121 to emit light, and then the laser 1121 emits light by mistake, resulting in the detection accuracy of the laser radar 1 being affected and the detection being unreliable.

[0056] In this way, the charging current in the charging stage can be made constant current through the first control circuit 1112, thereby ensuring the reliability of the laser 1121 emitting laser light, and the present application does not need to set up an additional boost circuit (such as a boost inductor) to charge the energy storage element 1111, the structure is simple, and there is no boost process, the energy loss is low, the heat generation is reduced, and the heat dissipation cost is saved. At the same time, the frequency of the laser emission of the constant current emission circuit 11 can be made higher, so that the laser radar 1 can achieve a high point frequency when emitting laser light.

[0057] In addition, the constant current power adjustable module 111 provided in the embodiment of the present application can control the conduction state and conduction time of the first control circuit 1112 and the second control circuit 1113 to adjust the charging state of the energy storage element 1111 and the amount of energy stored in the energy storage element 1111 when the power supply voltage is connected. Moreover, since the other end of the second control circuit 1113 is grounded, that is, the reference level is always 0V, the second control circuit 1113 always has a stable voltage difference, there is no voltage charging process of the bootstrap capacitor, and the response speed is fast. Moreover, when the second control circuit 1113 is turned off, the charging loop formed by the first control circuit 1112, the energy storage element 1111 and the second control circuit 1113 will be immediately turned off. Therefore, the charging state of the energy storage element 1111 and the amount of energy stored in the energy storage element 1111 can be accurately controlled, thereby ensuring the reliability of the laser emission.

[0058] Here, it is worth noting that the conduction state and conduction time of the first control circuit 1112 and the second control circuit 1113 are controlled and set by the controller 12. Moreover, when the energy storage element 1111 releases energy, the second control circuit 1113 is turned off, and the ground conduction loop of the energy storage element 1111 is quickly cut off, thereby ensuring the energy release accuracy of the energy storage element 1111, and further ensuring the accuracy of the constant voltage emission module 112 emitting lasers.

[0059] Optional, see Figure 7 , the first control circuit 1112 may be a first high-side switch (eg Figure 7 As shown in Q3), below, the energy storage element 1111 is used as the energy storage capacitor (as shown in Figure 7C2) is shown as an exemplary introduction, the drain of the first high side switch Q3 is connected to the transmitting power supply V3, the source of the first high side switch Q3 is connected to the first end of the energy storage capacitor C2, and the controlled end (i.e., the gate) of the first high side switch Q3 is connected to the power control signal. Here, it can be understood that the power control signal is provided by the controller 12, and the adjustment frequency of the power control signal can be adjusted according to different requirements, so as to adjust the conduction state and conduction time of the first high side switch Q3. In the charging stage, the charging current flowing to the energy storage capacitor C2 can be made constant current through the first high side switch Q3. The following is an exemplary description of the first high side switch Q3 provided in the present application based on the power supply voltage provided by the transmitting power supply V3 being a constant voltage or a non-constant voltage.

[0060] The first type: the power supply voltage provided by the transmitting power supply V3 is a constant voltage.

[0061] Initially, the voltage of the energy storage capacitor C2 is 0V (volts) or low voltage. At this time, the voltage difference between the energy storage capacitor C2 and the transmitting power supply V3 is large. After the charging stage begins, due to the large voltage difference between the energy storage capacitor C2 and the transmitting power supply V3, the first high-side switch Q3 will start to rise rapidly from the current of 0 in a short time, thereby entering the saturation zone, that is, at this time, the current flowing through the first high-side switch Q3 and flowing to the energy storage capacitor C2 is a constant current, which ensures the reliability of the use of the laser 1121 during the charging stage. Then, the linear conduction time of the first high-side switch Q3 is adjusted by the power control signal, thereby realizing the precise control of the energy stored in the energy storage capacitor C2 by the first high-side switch Q3, that is, realizing the linear control of the laser power emitted by the laser 1121. After the charging stage ends, the energy release stage begins. At this time, the energy storage capacitor C2 releases energy so that the laser 1121 emits a laser of corresponding power. In this way, by adjusting the conduction state and conduction time of the first high-side switch Q1, the laser 1121 can emit lasers of different powers, so that the laser radar 1 can detect target objects in a wider range of different distances, thereby expanding the detection range of the constant current transmitting circuit 11.

[0062] Here, it is worth noting that as the energy storage capacitor C2 is continuously charged during the charging stage, the voltage difference between the energy storage capacitor C2 and the transmitting power supply V3 gradually decreases until it is reduced to a certain value, which may cause the first high-side switch Q3 to be in a variable resistance zone. At this time, the current flowing through the first high-side switch Q3 and flowing to the energy storage capacitor C2 is not a constant current. In order to avoid the charging current being unstable in this case, thereby affecting the reliability of the subsequent laser 1121 emitting a laser, the present application can set the power supply voltage of the transmitting power supply V3 to be higher than or equal to the target voltage of the energy storage capacitor C2. In this way, the current will quickly rise to the saturation zone (constant current) at the beginning. When approaching the target voltage, the first high-side switch Q3 enters the variable resistance zone, and the current decreases rapidly, so that the energy storage capacitor C2 is infinitely close to the target voltage. At this time, enough time is reserved for charging, that is, to ensure that each path can reach a voltage close to the target voltage. In this way, in the charging stage, before the voltage of the energy storage capacitor C2 reaches the target voltage, the voltage difference between the energy storage capacitor C2 and the transmitting power supply V3 is always greater than a certain value, so that the first high-side switch Q3 is still in the saturation zone, that is, at this time, the current flowing through the first high-side switch Q3 and flowing to the energy storage capacitor C2 is a constant current, thereby ensuring the reliability of the use of the laser 1121 during the charging stage.

[0063] The second type: the power supply voltage provided by the transmitting power supply V3 is a non-constant voltage.

[0064] Initially, the voltage of the energy storage capacitor C2 is 0V (volts) or low voltage, and at this time, the voltage difference between the energy storage capacitor C2 and the transmitting power supply V3 is large. After the charging stage begins, due to the large voltage difference between the energy storage capacitor C2 and the transmitting power supply V3, the first high-side switch Q3 will be in the saturation region, that is, at this time, the current flowing through the first high-side switch Q3 and flowing to the energy storage capacitor C2 is a constant current, ensuring the reliability of the use of the laser 1121 during the charging stage. As the energy storage capacitor C2 is continuously charged during the charging stage, the voltage of the energy storage capacitor C2 increases. At this time, the power supply voltage provided by the transmitting power supply V3 can be increased, so that the voltage difference between the voltage of the energy storage capacitor C2 after the voltage increase and the increased power supply voltage is still large, so that the first high-side switch Q3 is still in the saturation zone, that is, the current flowing through the first high-side switch Q3 and flowing to the energy storage capacitor C2 is a constant current, so that the charging current of the energy storage capacitor C2 is still less than the current threshold required for the laser 1121 to emit light, avoiding the problem of false light emission of the laser 1121, thereby ensuring the accuracy and reliability of the constant voltage transmitting module 112 to emit laser, and further ensuring the detection accuracy and reliability of the laser radar 1.

[0065] In summary, the present application can limit the first high-side switch Q1 to operate in the saturation region so that the charging current flowing through the first high-side switch Q1 and into the energy storage capacitor C2 is a constant current, thereby ensuring the reliability of the use of the laser 1121, and there is no need to set up additional devices to limit the charging current, and the structure is simple.

[0066] In an example, see Figure 8 The first control circuit 1112 may further include a third low-side switch (eg Figure 8 Q4), the source of the third low-side switch Q4 is grounded, the drain of the third low-side switch Q4 is connected to the source of the first high-side switch Q3, and the controlled end of the third low-side switch Q4 is used to access the power control signal. At this time, the adjustment frequency of the power control signal can be adjusted to adjust the conduction state and conduction time of the first high-side switch Q3 and the third low-side switch Q4, so as to accurately control the energy state of the energy storage capacitor C2 and the energy stored in the energy storage capacitor C2, thereby ensuring the reliability of laser emission.

[0067] Here, it is worth explaining that after the energy release phase of the energy storage element 1111 ends, some energy usually remains in the energy storage capacitor C2. At this time, when the first low-side switch Q6 is in the on state, some of the remaining energy in the energy storage capacitor C2 may be released through the first low-side switch Q6 in the on state, that is, there is energy reflux. In this way, there is a certain amount of energy loss, resulting in more energy being required when charging the energy storage capacitor C2 next time, thereby extending the time required for the energy storage element 1111's charging phase, which is inconsistent with the preset charging time. In this way, the energy release phase of the energy storage element 1111 may be unstable, thereby reducing the reliability of the laser emission.

[0068] In order to avoid the problem that energy backflow occurs in the energy storage capacitor C2 after the energy storage element 1111 releases energy, which may lead to a decrease in the reliability of the laser emission, please refer to Figure 8 The high-side control circuit 1112 may further include a second high-side switch (eg Figure 8 As shown in FIG. 1 , the source of the second high-side switch Q5 is connected to the source of the first high-side switch Q3, the drain of the second high-side switch Q5 is connected to the first end of the energy storage capacitor C2, and the controlled end of the second high-side switch Q5 is connected to the power control signal. In this way, the additional second high-side switch Q5 can form a pair of switches with the first high-side switch Q3, and the second high-side switch Q5 and the first high-side switch Q3 realize capacitor bootstrapping, thereby isolating the energy reflux problem of the energy storage capacitor C2, avoiding the problem of energy loss, and thus ensuring the adjustment reliability of the constant voltage power adjustable module 111, that is, ensuring the reliability of the constant voltage transmitting circuit 11 in emitting lasers.

[0069] Optional, see Fig. 9, the first control circuit 1112 may be a first switch (eg Fig. 9 As shown in FIG. 1 , the first switch K1 is connected in series between the transmitting power source V3 and the first end of the energy storage capacitor C2. The charging state of the energy storage element 1111 and the amount of energy stored in the energy storage element 1111 can be precisely controlled by controlling the on-state and on-time of the first switch K1, thereby ensuring the reliability of the laser emission. At this time, a current limiting element (e.g., a current limiting resistor, etc.) can be set to limit the charging current, and this application does not make specific restrictions on this.

[0070] The specific structure of the first control circuit 1112 provided in the embodiment of the present application can be set based on different laser radars 1. For example, if the laser radar 1 does not need to achieve ultra-low power consumption but develops towards miniaturization, the first control circuit 1112 can only set a single switch to make the structure simple to meet the miniaturization development. This application does not make any specific restrictions on this.

[0071] It needs to be emphasized again that the second control circuit 1113 provided in the embodiment of the present application can realize the control of rapid conduction and disconnection of the ground conduction loop of the energy storage capacitor C2 when the energy storage capacitor C2 is charged, so as to accurately control the charging energy of the energy storage capacitor C2 to ensure the accuracy of the energy release of the energy storage capacitor C2, that is, the power of the emitted laser can be accurately controlled, thereby ensuring the accuracy of the laser emitted by the constant voltage emission module 112. Exemplarily, in the charging stage, when the second control circuit 1113 is turned off, the charging loop is disconnected to achieve accurate control of the charging energy of the energy storage capacitor C2; in the energy release stage, the second control circuit 1113 is turned on, so that the energy released by the energy storage capacitor C2 flows to the laser 1121 to achieve narrow pulse laser emission. Here, it is worth noting that the specific circuit form of the second control circuit 1113 can be diverse.

[0072] In an example, see Fig.10 , the second control circuit 1113 may include a first low-side switch (such as Fig.10 Q6) and a second low-side switch (as Fig.10Q7 as shown), the drain of the first low-side switch Q6 is connected to the second end of the energy storage capacitor C2, the controlled end of the first low-side switch Q6 is connected to the energy storage control signal, the drain of the second low-side switch Q7 is grounded, the source of the second low-side switch Q7 is connected to the source of the first low-side switch Q6, and the controlled end of the second low-side switch Q7 is connected to the energy storage control signal. Here, it can be understood that the energy storage control signal is provided by the controller 12, and the adjustment frequency of the energy storage control signal can be adjusted according to different requirements, so as to adjust the conduction state and conduction time of the first low-side switch Q6 and the second low-side switch Q7. Through the first low-side switch Q6 and the second low-side switch Q7, when the energy storage capacitor C2 releases energy, the ground conduction loop of the energy storage capacitor C2 can be quickly turned on and off, thereby accurately controlling the charging energy of the energy storage capacitor C2.

[0073] In an example, see Fig.11 The second control circuit 1113 may further include a diode (such as Fig.11 As shown in D2), the anode of the diode D2 is connected to the second end of the energy storage capacitor C2, and the cathode of the diode D2 is grounded to play a role in voltage stabilization and protection, thereby ensuring the stability of the constant current power adjustable module 111. In this example, one end of the laser 1121 is grounded, and the other end of the laser 1121 is connected between the second end of the energy storage capacitor C2 and the anode of the diode D2. Taking the laser 1121 as a laser diode (LD) as an example, the anode of the laser diode is grounded, and the cathode of the laser diode is connected between the second end of the energy storage capacitor C2 and the anode of the diode D2. At this time, in the charging stage, the diode D2 is turned on to charge the energy storage capacitor C2. When the diode D2 is turned off, the charging loop is disconnected to achieve precise control of the charging energy of the energy storage capacitor C2; in the energy release stage, the energy released by the energy storage capacitor C2 flows into the anode of the laser diode and flows out from the cathode of the laser diode. At this time, since the characteristic of the diode D2 is unidirectional conductivity, the current flowing out from the cathode of the laser diode will flow into the second end of the energy storage capacitor C2 to form an energy release loop, thereby ensuring the energy release reliability in the energy release stage.

[0074] Optional, such as Fig.12 As shown, the second control circuit 1113 may include a second switch (such as Fig.12 As shown in FIG. 1 , the second switch K2 is connected in series between the second end of the energy storage capacitor C2 and the ground end. The second switch K2 can be used to quickly turn on and off the ground conduction loop of the energy storage capacitor C2 when the energy storage capacitor C2 releases energy, thereby accurately controlling the charging energy of the energy storage capacitor C2.

[0075] Here, it is worth noting that the second control circuit 1113 may also include other switching elements, and this application does not make any specific limitation on this.

[0076] Thus, the constant current power adjustable module 111 provided in the embodiment of the present application is provided with an energy storage element 1111, a first control circuit 1112 and a second control circuit 1113. By controlling the conduction state and conduction time of the first control circuit 1112 and the second control circuit 1113, the constant current transmitting circuit 11 can enable the laser 1121 to emit lasers of different powers based on the power supply voltage. The charging current flowing into the energy storage element 1111 can be made constant current through the first control circuit 1112, thereby ensuring the current stability connected to the energy storage element 1111, thereby avoiding the problem that the laser 1121 connected in parallel with the energy storage element 1111 is damaged by a large current shock and the laser 1121 emits light by mistake, and ensuring the reliability of the laser emitted by the constant current transmitting circuit 11. Moreover, the switching response speed of the second control circuit 1113 is fast, which ensures the overall reliability of the constant current transmitting circuit 11, so as to be suitable for different laser radars 1 and detection scenarios. The constant current transmitting circuit 11 in the present application does not need to be provided with additional charging elements and boosting circuits, and the overall structure is simple. In addition, the constant current transmitting circuit 11 does not have a boosting process, and the energy loss is low.

[0077] Here, it can be understood that the laser radar 1 provided in the embodiment of the present application can be a combination of one laser 1121 corresponding to one constant current power adjustable module 111, or a combination of a laser array composed of multiple lasers 1121 corresponding to one constant current power adjustable module 111, or a combination of a laser array composed of multiple lasers 1121 corresponding to multiple constant current power adjustable modules 111. Here, it is worth noting that the laser array can be composed of M*N lasers 1121, M and N are the number of rows and columns of the lasers 1121 included in the laser array, respectively, wherein M and N are both positive integers, and at least one of M and N is greater than or equal to 2, and the specific number can be set based on actual needs, and this application does not make specific restrictions on this.

[0078] Exemplarily, when the laser radar 1 is a combination of a laser array composed of multiple lasers 1121 and a constant current power adjustable module 111, more lasers 1121 can be arranged in the laser radar 1, and a constant current power adjustable module 111 controls the stimulated emission state of the laser 1121 and the power of the emitted laser, so that the overall uniformity of the emitted laser of the laser radar 1 is higher.

[0079] Exemplarily, when the laser radar 1 is a combination of a laser array composed of multiple lasers 1121 corresponding to multiple constant current power adjustable modules 111, in this way, each row, column or block of lasers 1121 in the laser array can be set to be controlled by an independent constant current power adjustable module 111, so that the accuracy of controlling the laser emitted by the laser radar 1 is higher, and, based on different needs, the emission power of lasers 1121 in different areas of the laser array can be different to achieve different detection effects, thereby improving the overall applicability of the laser radar 1. At the same time, the constant current power adjustable module 111 provided in the present application is not provided with charging devices such as inductors, so there is no difference between inductors, thereby avoiding the problem of poor consistency of the overall emitted laser, and, even if there are multiple constant current power adjustable modules 111 in the laser radar 1 provided in the embodiment of the present application, the heat generated by the overall circuit is also small, and the circuit loss is also low.

[0080] In an example, see Fig.13 The constant voltage transmitting module 112 may also include a transmitting control switch (such as Fig.13 Q8), the source of the emission control switch Q8 is connected to the laser 1121, and the laser 1121 is a laser diode (such as Fig.13 D3) is used as an example to explain that the source of the emission control switch Q8 is connected to the anode of the laser diode D4, the drain of the emission control switch Q8 is connected to the first end of the energy storage element 1111, the controlled end of the emission control switch Q8 is used to receive the emission control signal, and the cathode of the laser diode D4 is connected to the second end of the energy storage element 1111. Here, it can be understood that the emission control signal is provided by the controller 12, and the frequency of the emission control signal can be adjusted according to different requirements, so as to adjust the conduction state and conduction time of the emission control switch Q8.

[0081] During the charging stage of the energy storage element 1111, the emission control switch Q8 is turned off. During the energy release stage of the energy storage element 1111, the emission control switch Q8 is turned on, and the driving current released by the energy storage element 1111 passes through the emission control switch Q8 and the laser 1121 to the ground, forming an energy release loop to drive the laser 1121 to emit light. In this way, by controlling the on and off of the emission control switch Q8, the reliability of the use of the laser 1121 in different modes can be guaranteed, thereby ensuring the accuracy and reliability of the laser emitted by the constant voltage emission module 112, thereby ensuring the detection accuracy and reliability of the laser radar 1 using the constant voltage emission module 112.

[0082] Optionally, the laser 1121 may also be disposed between the energy storage element 1111 and the ground terminal. For example, the cathode of the laser 1121 is connected to the second end of the energy storage element 1111, and the anode of the laser 1121 is grounded. The specific location of the laser 1121 may be selected according to actual needs, and the present application does not impose any specific restrictions on this.

[0083] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0084] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A constant current transmitting circuit, characterized in that: The constant current transmitting circuit comprises: A constant current power adjustable module, comprising an energy storage element, wherein the input end of the constant current power adjustable module is used to be connected to a transmitting power supply that outputs a power supply voltage, so as to charge the energy storage element through the power supply voltage, and the constant current power adjustable module is used to provide a constant current to the energy storage element and adjust the amount of energy stored in the energy storage element; and The constant voltage emission module comprises a laser, which is connected to the energy storage element. The laser is used to emit laser when the energy storage element releases energy. Different energies stored in the energy storage element correspond to different laser emission powers.

2. The constant current transmitting circuit according to claim 1, characterized in that: The constant current power adjustable module also includes: A first control circuit, one end of which is connected to the transmitting power supply, and the other end of which is connected to the energy storage element; A second control circuit, one end of which is connected to the second end of the energy storage element and the other end of which is grounded; Wherein, when the energy storage element is charged, the first control circuit and the second control circuit are both turned on and the on time is controllable, so as to charge the energy storage element through the transmitting power supply and control the amount of energy stored in the energy storage element, and the current flowing through the first control circuit and into the energy storage element is a constant current; when the energy storage element releases energy, at least the first control circuit is turned off.

3. The constant current transmitting circuit according to claim 2, characterized in that: The first control circuit comprises: The first high-side switch has a drain electrode connected to the transmitting power source, a source electrode connected to the first end of the energy storage element, and a controlled end connected to a power control signal.

4. The constant current transmitting circuit according to claim 2, characterized in that: The first control circuit comprises: The first switch is connected in series between the transmitting power source and the first end of the energy storage element.

5. The constant current transmitting circuit according to any one of claims 2 to 4, characterized in that: The second control circuit comprises: A first low-side switch, a drain electrode of which is connected to the second end of the energy storage element, and a controlled end of which is used to access an energy storage control signal; The second low-side switch has a drain connected to the ground, a source connected to the source of the first low-side switch, and a controlled end for receiving the energy storage control signal.

6. The constant current transmitting circuit according to any one of claims 2 to 4, characterized in that: The second control circuit comprises: The diode has an anode connected to the second end of the energy storage element and a cathode connected to the ground.

7. The constant current transmitting circuit according to claim 6, characterized in that: The laser comprises: The laser diode has an anode connected to the ground and a cathode connected to the anode of the first diode and the second end of the energy storage element respectively.

8. The constant current transmitting circuit according to any one of claims 2 to 4, characterized in that: The second control circuit comprises: The second switch is connected in series between the second end of the energy storage element and the ground end.

9. The constant current transmitting circuit according to any one of claims 1 to 4 or 5, characterized in that: The constant voltage transmitting module also includes: An emission control switch, wherein the source is connected to the anode of the laser, the drain is connected to the first end of the energy storage element, the controlled end is used to receive an emission control signal, and the cathode of the laser is connected to the second end of the energy storage element; Wherein, when the energy storage element is charged, the emission control switch is turned off, and when the energy storage element is released, the emission control switch is turned on.

10. A laser radar, characterized in that: include: At least one constant current transmitting circuit as claimed in any one of claims 1 to 9; A controller connected to the constant current power adjustable module and the constant voltage transmitting module; The laser receiving circuit is connected to the controller and is used to receive the echo light formed by the laser emitted by the constant current transmitting circuit being reflected by the target object.

11. The laser radar according to claim 9, characterized in that: The laser radar further comprises: The laser array is composed of M*N lasers, where M and N are respectively the number of rows and columns of the lasers included in the laser array, and both M and N are positive integers, and at least one of M and N is greater than or equal to 2.

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