Device and method for suppressing the emission of parasitic laser pulses by uncontrolled lasers of a laser array

Abstract

Lidar system the lidar system includes a control circuit (CTR) and the lidar system has a plurality of charging circuits (B1 to Bn) and the lidar system uses a plurality of capacitors (C1 to Cn) and the lidar system comprises a plurality of lasers (D1 to Dn) and where n is a positive integer greater than 1 and wherein the control device CTR is set up to control the n charging circuits (B1 to Bn) and wherein the control circuit CTR is configured to cause a charging circuit of the n charging circuits (B1 to Bn), hereinafter referred to as the j-th charging circuit (Bj), to charge a capacitor of the n capacitors (C1 to Cn), hereinafter referred to as the j-th capacitor (Cj), to an energy level other than zero and wherein the control circuit (CTR) is configured to cause the other n-1 charging circuits of the n charging circuits (B1 to Bn), which are not the j-th charging circuit (Bj), to each discharge one capacitor of the other n-1 capacitors, which are not the j-th capacitor, substantially to a parasitic residual energy level, which may be zero, and wherein this charge is generated before a light pulse by a j-th laser (Dj) and wherein the control circuit (CTR) for initiating the generation of the light pulse by the j-th laser (Dj) includes a control switch (T) dis ) closes and where the closing of the control switch (T dis ) connects a common star point (DisC) with a reference potential and wherein the cathodes of the lasers (D1 to Dn) are connected to the star point (DisC) and where each of the n capacitors has a first and a second terminal and wherein the second terminal of each capacitor is connected to the reference potential and where for each of the n capacitors, the first terminal of this capacitor is connected to the anode of exactly one laser and this first terminal is not connected to any other laser or to the first terminal of any other capacitor, so that the closing of the control switch (T dis ) to a discharge of the j-th capacitor via the j-th laser (Dj) and the control switch (T dis ) by emitting a light pulse, characterized by that the control circuit (CTR) causes the other n-1 charging circuits of the n charging circuits (B1 to Bn), which are not the j-th charging circuit (Bj), to each discharge capacitor of the other n-1 capacitors, which are not the j-th capacitor, essentially to a parasitic residual energy level, which may be zero, and that these discharges occur before the generation of a light pulse by the j-th laser (Dj) and that the control circuit (CTR) measures the residual voltage of the j-th capacitor (Cj) after it has discharged, in particular by means of an analog-to-digital converter.

Description

Field of invention

[0001] The invention relates to a lidar system and a method for operating this lidar system, wherein the lidar system and the method for operating this lidar system suppress the emission of laser pulses by lasers of a laser array that are not intended to emit laser pulses. General Introduction

[0002] The only Fig. Paragraph 1 is taken from the international patent application WO 2021 / 140160 A1, which was unpublished at the time of filing the present document. In connection with this document, we also refer to the German patent applications DE 10 2020 114782 A1 and DE 10 2020 124564 A1, which were also unpublished at the time of filing.

[0003] Fig. Figure 1 shows an exemplary circuit for the LIDAR system proposed in WO 2021 / 140 160 A1. A control circuit CTR causes one of n charging circuits B1 to Bn to charge a capacitor C1 to Cn via a charging line K1 to Kn assigned to this charging circuit. Here, n is a positive integer. For simplification, the following are shown in the Fig.Figure 1 shows only the components with indices 1 to 3 and the index n. The knowledgeable reader will infer the undrawn components with indices 4 to (n-1). Naturally, it should generally hold that 1 ≤ n and n ∈ N. Each of the n charging lines K1 to Kn has a (primarily parasitic) resistance RZ1 to RZn and a parasitic inductance LZ1 to LZn. Each of the charging lines K1 to Kn is preferably connected to a first terminal of exactly one of the n capacitors C1 to Cn. A second terminal of each of the n capacitors C1 to Cn is connected to a reference potential GND via a line. Each of the lines between the second terminal of a capacitor C1 to Cn and the reference potential GND includes a parasitic resistance RC1 to RCn and a parasitic inductance LC1 to LCn.The anode of preferably exactly one of the n lasers D1 to Dn is preferably connected to the first terminal of preferably exactly one of the n capacitors C1 to Cn via preferably exactly one discharge line of n discharge lines K1' to Kn'. The cathodes of the n lasers D1 to Dn are connected to a common first neutral point DisC. This common neutral point DisC is activated upon the arrival of a pulse signal G. dis by a control switch T dis connected to the reference potential GND. The second terminals of the n capacitors C1 to Cn are also connected to the reference potential GND.

[0004] An example buffer in the form of a driver Buf generates the pulse signal G from a pulse pre-signal PL. dis to open the control switch T disPreferably, the control circuit CTR can generate this pulse pre-signal PL when the charging process for the capacitor to be charged of the n capacitors C1 to Cn is completed by the associated charging circuit B1 to Bn and the charging circuit B1 to Bn is switched to neutral.

[0005] The n capacitors C1 to Cn typically form a capacitor array.

[0006] A decoupling capacitor CVDD is preferably part of the capacitor array consisting of n capacitors C1 to Cn. The decoupling capacitor CVDD stabilizes the supply voltage VDD or another system-relevant voltage. The decoupling capacitor CVDD serves to prevent the effects of current surges that occur during the ignition of the lasers D1 to Dn on other components connected to the supply voltage VDD, e.g., components of a vehicle with the supply voltage VDD as its electrical system voltage.

[0007] The first connection of the decoupling capacitor CVDD is connected to the supply voltage VDD via a line inductance LZV and a line resistance RZV.

[0008] A second terminal of the decoupling capacitor CVDD is connected to the reference potential GND via a line resistor RCV and a line inductance LCV.

[0009] The control circuit CTR controls the n charging circuits B1 to Bn and generates the pulse pre-signal PL. The control circuit CTR selects a j-th channel of the n channels with 1 ≤ j ≤ n and j ∈ ℕ. By activating this j-th channel, the control circuit CTR causes, for example, a j-th charging circuit Bj of the n charging circuits B1 to Bn with 1 ≤ j ≤ n and j ∈ ℕ, typically a j-th capacitor Cj of the n capacitors C1 to Cn, to be charged with energy to a predefined energy level before the generation of a light pulse by a j-th laser Dj of the n lasers D1 to Dn, according to the technical teaching of WO 2021 / 140 160 A1. The technical teaching of WO 2021 / 140 160 A1 now proposes that the control circuit CTR cause the other n-1 charging circuits B1 to B(j-1) and B(j+1) to Bn to preferably switch off all charging circuits B1 to Bn after the charging process has been completed, or to preferably switch the charging outputs of all charging circuits B1 to Bn to high impedance.The control circuit CTR then closes the control switch T. dis This initiates the generation of light pulses by the j-th laser (Dj) of the n lasers D1 to Dn. This is repeated iteratively for all channels j where 1 ≤ j ≤ n, until all n lasers D1 to Dn have preferably emitted exactly one light pulse. The control circuit then starts again from the beginning with the next iteration.

[0010] Leakage currents typically lead to a parasitic charging of the other n-1 capacitors C1 to C(j-1) and C(j+1) to Cn. If the control circuit CTR now closes the control switch T dis This also discharges the other capacitors C1 to C(j-1) and C(j+1) to Cn via the other lasers D1 to D(j-1) and D(j+1) to Dn. Experience has shown that this leads to an undesirable glow from the other lasers D1 to Dn.

[0011] US patent 2020 / 0178361A1 discloses a control concept for a light emission system in which several capacitors and switching elements are used to selectively energize individual laser diodes. The aim is to prevent parasitic light emissions from lasers that are not actively driven by interrupting certain current paths. Nevertheless, parasitic capacitances and induced currents can lead to unwanted luminescence from undriven laser diodes, resulting in reduced measurement accuracy. Task

[0012] The proposal is therefore based on the objective of creating a solution that does not exhibit this parasitic luminescence of the other lasers D1 to Dn and offers further advantages. This objective is achieved by a device and a method according to the independent claims. Solution to the task

[0013] In a lidar system of the type described above, the problem is solved as proposed by having the other control circuits B1 to B(j-1) and B(j+1) to Bn connect the other capacitors C1 to C(j-1) and C(j+1) to Cn before the control switch T is closed. dis discharge, while the j-th control circuit Bj charges the j-th capacitor Cj with the energy required to fire.

[0014] The proposed device and method are therefore as follows: The control circuit CTR controls the n charging circuits B1 to Bn and generates the pulse pre-signal PL as already described in WO 2021 / 140 160 A1. The control circuit CTR selects a j-th channel of the n channels with 1 ≤ j ≤ n and j ∈ ℕ. The j-th channel comprises the j-th charging circuit Bj of the n charging circuits B1 to Bn with 1 ≤ j ∈ n and j ∈ ℕ, the j-th capacitor Cj of the n capacitors C1 to Cn, and the j-th laser Dj of the n lasers D1 to Dn, each with 1 ≤ j ∈ n and j ∈ ℕ. All n channels terminate at the star point DisC. According to the technical teaching of WO 2021 / 140 160 A1, the control circuit CTR, for example, causes a j-th charging circuit Bj, typically a j-th capacitor Cj, to be charged with energy to a predefined energy level before the generation of a light pulse by a j-th laser Dj, to activate this j-th channel.In contrast to the technical teaching of WO 2021 / 140 160 A1, the present document proposes that the control circuit CTR, in order to suppress parasitic activation of one or more or all of the n-1 other channels, for example, to cause the other n-1 charging circuits to discharge typically one or more or preferably all of the other n-1 capacitors of the n capacitors C1 to Cn to the lowest possible energy level before the generation of a light pulse by the j-th laser Dj of the n lasers D1 to Dn, and to extract as much energy as possible from these other n-1 capacitors. The other n-1 channels are channels 1 to j-1 and j+1 to n. The other n-1 charging circuits are the first charging circuit B1 to the (j-1)th charging circuit B(j-1) and the (j+1)th charging circuit B(j+1) to the nth charging circuit Bn.The n-1 other capacitors are the first capacitor C1 to the (j-1)th capacitor C(j-1) and the (j+1)th capacitor C(j+1) to the nth capacitor Cn. This energy withdrawal prevents parasitic emission of light energy by the other n-1 lasers of the n lasers D1 to Dn when the control CTR is closed by closing the control switch T. dis This causes the j-th laser Dj to emit a laser pulse. Since the other capacitors C1 to C(j-1) and C(j+1) to Cn have not stored a sufficient amount of energy, closing the control switch T results in disThis prevents parasitic glow from the other lasers D1 to D(j-1) and D(j+1) to Dn. The control circuit CTR then preferentially switches off the j-th charging circuit Bj, or rather, sets the charging output of the j-th charging circuits Bj to high impedance, after the charging process of the j-th capacitor Cj has been completed and, additionally, only after the discharge process of the other capacitors C1 to C(j-1) and C(j+1) to Cn has also been completed. In contrast to the technical teaching of WO 2021 / 140 160 A1, the control circuit CTR now also preferentially does not switch off the other charging circuits B1 to B(j-1) and B(j+1) to Bn after the charging process of the j-th capacitor Cj has been completed and the discharge process of the other capacitors C1 to C(j-1) and C(j+1) and Cn has also been completed.Rather, after the charging process of the j-th capacitor has been completed and the discharge process of the other capacitors C1 to C(j-1) and C(j+1) and Cn has also been completed, the control circuit CTR preferably switches on the other charging circuits B1 to B(j-1) and B(j+1) to Bn, or preferably switches the charging output of the other charging circuits B1 to B(j-1) and B(j+1) to Bn to a low impedance. The control circuit CTR thus fixes the potentials of the other discharge lines K1 to K(j-1) and K(j+1) to Kn by means of the other charging circuits B1 to B(j-1) and B(j+1) to Bn. With the help of the other charging circuits B1 to B(j-1) and B(j+1) to Bn, the control circuit therefore prevents parasitic light emission from the n-1 other lasers D1 to D(j-1) and D(j+1) to Dn. As in the prior art, the control circuit CTR then selects a k-th channel of the n channels with 1≤k≤n and k∈ℕ instead of the j-th channel.The control circuit CTR repeats the previously described process for this k-th channel instead of the j-th channel, and thus for the emission of a laser pulse using the k-th laser Dk instead of the j-th laser Dj, until all n lasers D1 to Dn have preferably emitted a light pulse exactly once, and then starts again from the beginning with the next pass.

[0015] Basically, the proposed lidar system can operate in 3 operating modes. Operating mode 1

[0016] In operating mode 1, the relevant j-th charging circuit of the channel whose j-th laser Dj is to emit a laser pulse charges the associated j-th capacitor Cj. The n-1 charging circuits B1 to B(j-1) and B(j+1) to Bn discharge their associated n-1 capacitors C1 to C(j-1) and C(j+1) to Cn. The electrical charge that the j-th charging circuit Bj applies to the j-th capacitor Cj in operating mode 1 is not time-limited and is therefore only limited by saturation effects of the charging process. Operating mode 2

[0017] In operating mode 2, the relevant j-th charging circuit of the channel whose j-th laser Dj is to emit a laser pulse charges the associated j-th capacitor Cj during a predefined charging time with a charging current whose value is preferably predetermined and / or regulated according to a setpoint. The n-1 charging circuits B1 to B(j-1) and B(j+1) to Bn discharge their associated n-1 capacitors C1 to C(j-1) and C(j+1) to Cn. The electrical charge that the j-th charging circuit Bj applies to the j-th capacitor Cj in operating mode 1 is now limited by the charging time. The capacitor voltage is only modified by variations in the capacitor value from channel to channel.

[0018] After closing the control switch T disFollowing the emission of the light pulse by the j-th laser Dj, the j-th charging circuit Bj is in an idle state. The idle state means that in this operating mode, the output of the j-th charging circuit is high-impedance. An analog-to-digital converter (ADC) of the control circuit CTR performs a measurement and measures the residual voltage of the j-th capacitor Cj. This allows a) the determination of the actual emitted energy and b) the determination of the residual energy in the j-th capacitor Cj. This calculation can be performed, for example, by a microcomputer, which can be part of the control circuit CTR. Preferably, this microcomputer then recalculates the next subsequent charging time for this j-th channel based on the residual voltage detected by the ADC. The control circuit CTR then sets precisely this newly calculated charging time as the charging time immediately before the next charging of the j-th capacitor Cj. Operating mode 3

[0019] The j-th channel is to emit a laser pulse. For this purpose, the j-th charging circuit Bj is to charge the j-th capacitor Cj. Before this charging process of the j-th capacitor Cj, the other drive circuits B1 to B(j-1) and B(j+1) to Bn discharge the other capacitors C1 to C(j-1) and C(j+1) to Cn. In this operating mode, the controller CTR performs this discharge process of the other capacitors C1 to C(j-1) and C(j+1) to Cn before the charging of the j-th capacitor Cj. This is a compromise to prevent the laser diodes of the lasers from burning out due to the discharge of the non-firing channels. A small amount of crosstalk is accepted for this, but it cannot accumulate because a new discharge is performed before the next cycle. SUMMARY OF THE DEVICE

[0020] This document describes a lidar system. The lidar system comprises a control circuit CTR, n charging circuits B1 to Bn, n capacitors C1 to Cn, and n lasers D1 to Dn. For the purposes of this document, n is a positive integer greater than 1, which is assumed to be the same within a device. The control device CTR controls the n charging circuits B1 to Bn. The control circuit CTR, as intended, causes one of the n charging circuits B1 to Bn, hereinafter referred to as the j-th charging circuit Bj, to charge exactly one of the n capacitors C1 to Cn, hereinafter referred to as the j-th capacitor Cj, to a non-zero energy level. This energy is later used to operate the j-th laser Dj, which is associated with this j-th capacitor Cj.The control circuit CTR causes the other charging circuits of the n charging circuits B1 to Bn, which are not the j-th charging circuit Bj, to each discharge exactly one capacitor from the other n-1 capacitors, which are not the j-th capacitor, essentially to a parasitic residual energy level, which can be zero. Preferably, each charging circuit of the n charging circuits B1 to Bj is assigned exactly one capacitor from the n capacitors C1 to Cn for charging or discharging. This charging takes place before the generation of a light pulse by a laser, hereinafter referred to as the j-th laser Dj. This j-th laser is assigned to the j-th capacitor Cj. The control circuit CTR closes a control switch T to initiate the generation of the light pulse by the j-th laser Dj. dis . Closing the control switch T disconnects a common neutral point DisC to a reference potential. The cathodes of the n lasers D1 to Dn are electrically connected to the neutral point DisC directly or indirectly via other, especially parasitic, components. Each of the n capacitors has a first and a second terminal. The second terminal of each of the n capacitors C1 to Cn is connected to the reference potential GND. For each of the n capacitors C1 to Cn, the first terminal of this capacitor is connected to the anode of exactly one of the n lasers D1 to Dn, and this first terminal is not connected to any other laser of the n lasers D1 to Dn or to the first terminal of any other capacitor of the n capacitors C1 to Cn. Thus, closing the control switch T results in dis to a discharge of the j-th capacitor Cj via the j-th laser Dj and the control switch T diswith the emission of a light pulse. The proposal presented here is characterized by the fact that the control circuit CTR causes the other charging circuits of the n charging circuits B1 to Bn, which are not the j-th charging circuit Bj, to discharge one capacitor of each of the other n-1 capacitors, which are not the j-th capacitor, essentially to a parasitic residual energy level, which can be zero. These discharges of the other capacitors C1 to C(j-1) and C(j+1) to Cn occur before the generation of a light pulse by a laser, hereinafter referred to as the j-th laser Dj. This j-th laser Dj is assigned to the previously charged j-th capacitor Cj and thus to the j-th charging circuit Bj.

[0021] In a preferred further embodiment of the device, the control circuit CTR switches after the charging process of the j-th capacitor Cj has been completed and after the discharging process of the other capacitors has been completed and before the control switch T is closed. disThe j-th charging circuit Bj is disconnected and / or the charging output of the j-th charging circuits Bj is switched to high impedance. This has the advantage that the energy used to emit the laser pulse can be precisely determined beforehand by monitoring the charging process. This can be done by monitoring the charging current and the charging time and / or by monitoring the capacitor voltage. Preferably, the j-th charging circuit Bj charges the j-th capacitor Cj with a predetermined amount of energy, which is the product of charging time times voltage times current. Preferably, the control device CTR and / or the j-th charging circuit firstly detects instantaneous charging current values ​​for the charging current into the first terminal of the j-th capacitor Cj and secondly, synchronously detects instantaneous capacitor voltage values ​​of the first capacitor terminal of the j-th capacitor Cj, for example, against a reference potential. The control device CTR or...The j-th charging circuit Bj then determines an instantaneous value of the additional electrical power stored in the j-th capacitor from an instantaneous charging current value and the capacitor voltage value, which is measured synchronously with this current. By integrating the time-dependent values ​​of the instantaneous value of the additional electrical power stored in the j-th capacitor, the control device or the drive circuit obtains a time-dependent profile of the energy content of the j-th capacitor Cj. When the energy content of the j-th capacitor (Cj) reaches a predetermined energy value, the control device CTR or the j-th charging circuit Bj interrupts the charging of the j-th capacitor Cj.Switching the charging output of the j-th charging circuit to high impedance prevents any further change in the energy content of the j-th capacitor Cj after the charging process has ended, so that the energy subsequently emitted by the j-th laser Dj is well controlled.

[0022] In a preferred further embodiment of the device, the control circuit CTR switches after the charging process of the j-th capacitor Cj has been completed and after the discharging process of the other capacitors has been completed and before the control switch T is closed. dis The other charging circuits B1 to B(j-1) and B(j+1) to Bn are preferably switched on and not off. Switching the charging output of these other charging circuits B1 to B(j-1) and B(j+1) to Bn to a low impedance is equivalent to this and may be an alternative. This brings the anode potential of the other laser diodes D1 to D(j-1) and D(j+1) to Dn to a defined potential. Closing the control switch Tdis The anodes of these other laser diodes cannot then be dynamically disturbed by capacitive coupling via the junction capacitances of the laser diodes. This prevents parasitic emission from these other lasers when the control switch T is closed. dis prevented. SUMMARY OF THE PROCEDURE

[0023] This document also describes a method for operating a lidar system. The lidar system underlying the method comprises n capacitors C1 to Cn and n lasers D1 to Dn. As before, n is a positive integer greater than 1, which is always the same for the lidar system. The cathodes of the lasers D1 to Dn are, by assumption, connected to a neutral point DisC. Each of the n capacitors again has a first and a second terminal. The second terminal of each capacitor is again connected to the reference potential. For each of the n capacitors, the first terminal of this capacitor is connected to the anode of exactly one laser and is not connected to any other laser or to the first terminal of any other capacitor.One of the n capacitors C1 to Cn, hereinafter referred to as the j-th capacitor Cj, is assigned to a laser, hereinafter referred to as the j-th laser Dj. In the further course of the procedure, this j-th laser Dj is to emit a laser pulse, while the procedure suppresses the emission of parasitic laser pulses by the other n-1 lasers D1 to D(j-1) and D(j+1) to Dn. The closing of the control switch T. dis This then leads to a discharge of the possibly previously charged j-th capacitor Cj via the j-th laser Dj and the control switch T. disThe method involves charging one of the n capacitors C1 to Cn, hereinafter referred to as the j-th capacitor Cj, to a non-zero energy level prior to the generation of a light pulse by a laser, hereinafter referred to as the j-th laser Dj and / or "laser to be operated". This charging occurs in parallel with the generation of a desired light pulse by the j-th laser Dj, provided that the j-th capacitor Cj has previously been charged with a sufficient amount of energy by the charging circuit Bj. The method thus includes charging one of the n capacitors C1 to Cn, hereinafter referred to as the j-th capacitor Cj, to a non-zero energy level prior to the generation of a light pulse by a laser, hereinafter referred to as the j-th laser Dj and / or "laser to be operated". Simultaneously, the other n-1 capacitors, which are not the j-th capacitor, are selectively discharged, essentially to a parasitic residual energy level, which may be zero. This discharge occurs prior to the generation of a light pulse by the j-th laser Dj. The proposed method thereby prevents the other n-1 lasers D1 to D(j-1) and D(J+1) to Dn from emitting parasitic light pulses.After this loading and unloading process, a control switch T is closed. dis to initiate the generation of the light pulse by the j-th laser Dj, wherein the closing of the control switch T dis connects the common star point DisC with a reference potential.

[0024] In a refinement of the proposed method for operating a lidar system, the lidar system comprises n charging circuits B1 to Bn for charging the n capacitors C1 to Cn. Each capacitor of the n capacitors C1 to Cn is furthermore assigned exactly one laser of the n lasers D1 to Dn. Each capacitor of the n capacitors C1 to Cn is assigned exactly one charging circuit of the n charging circuits B1 to Bn to discharge that capacitor or to charge it with energy to operate the laser assigned to that capacitor. The control circuit CTR controls the n charging circuits B1 to Bn. The refinement of the method then additionally includes the step of switching off and / or setting high impedance to the charging output of the j-th charging circuit Bj, which was previously used to charge the j-th capacitor Cj.This switching off and / or switching to high impedance of the charging output of the j-th charging circuits Bj takes place after the charging process of the j-th capacitor Cj has been completed and after the discharging process of the other capacitors has been completed and before the control switch T is closed. dis .

[0025] In a second refinement of the method for operating a lidar system, the lidar system comprises n charging circuits B1 to Bn for charging the n capacitors C1 to Cn. Each of the n capacitors C1 to Cn is assigned exactly one laser, the n lasers D1 to Dn. Each of the n capacitors C1 to Cn is assigned exactly one charging circuit, the n charging circuits B1 to Bn, to either discharge it or charge it with energy to operate the laser assigned to that capacitor. This second refinement of the method then includes the additional step of switching on and / or switching to low impedance the charging output of the other charging circuits B1 to B(j-1) and B(j+1) to Bn, which were used to discharge the other capacitors C1 to C(j-1) and C(j+1) to Cn.This occurs after the charging process of the j-th capacitor Cj has been completed and after the discharging process of the other capacitors has been completed and before the control switch T is closed. dis .

[0026] The above methods always operate only one laser, the j-th laser Dj, and suppress the emission from the other lasers. To scan the laser array as an emission sequence of light pulses from all lasers D1 to Dn, the following method is proposed: This third refinement of the procedure for executing a beam sequence of a lidar system essentially comprises the following three steps: In step 1 of the emission sequence, a j-th laser is selected as the laser to be operated from the n lasers D1 to Dn. When step 1 is executed for the first time, the number j is any, for example, randomly selected or predetermined positive integer between 1 and n. In step 2 of the emission sequence of the procedure, a procedure for emitting a laser pulse by a laser, namely the j-th laser Dj, is carried out. In step 3 of the emission sequence, if not all lasers to be operated within the emission sequence have already been operated once within the time of the emission sequence, a k-th laser is selected as the laser to be operated from the n lasers D1 to Dn, wherein the k-th laser is different from the j-th laser and preferably from all lasers already operated within the emission sequence.

[0027] The process then repeats step 2 of the emission sequence, where k is the k-th laser in the further course, becoming the new j-th laser.

[0028] In this way, all lasers gradually emit their laser pulses, with the process actively preventing the other lasers from emitting parasitic light pulses each time a laser pulse is emitted by one laser. Advantage

[0029] Such a device, at least in some implementations, enables a significant reduction in crosstalk of light emission to other channels. However, the advantages are not limited to this. Reference symbol list B1 first charging circuit; B2 second charging circuit; B3 third charging circuit; B(j-1) (j-1)th charging circuit; Year j-th charging circuit; B(j+1) (j+1)th charging circuit; Bn nth charging circuit; Buf driver, which converts the pulse pre-signal PL to the pulse signal G dis reinforced; C1 first capacitor; C2 second capacitor; C3 third capacitor; C(j-1) (j-1)-ter Condensator; Cj j-ter Kondensator; C(j+1) (j+1)-ter Condensator; Cn n-ter Kondensator; The CTR control circuit controls the n charging circuits B1 to Bn and generates the pulse pre-signal PL. The CTR control circuit selects a j-th channel of the n channels with 1 ≤ j ≤ n and j ∈ ℕ. By activating this j-th channel, the CTR control circuit causes, for example, a j-th charging circuit Bj of the n charging circuits B1 to Bn with 1 ≤ j ≤ n and j ∈ ℕ, typically a j-th capacitor Cj of the n capacitors C1 to Cn, to be charged with energy to a predefined energy level before the generation of a light pulse by a j-th laser Dj of the n lasers D1 to Dn, according to the technical teaching of WO 2021 / 140 160 A1.In contrast to the technical teaching of WO 2021 / 140 160 A1, the present document proposes that the control circuit CTR, in order to suppress parasitic activation of one or more or all of the n-1 other channels, for example, to cause the other n-1 charging circuits to discharge typically one or more or preferably all of the other n-1 capacitors of the n capacitors C1 to Cn to the lowest possible energy level and to extract as much energy as possible before the generation of a light pulse by the j-th laser Dj of the n lasers D1 to Dn. The other n-1 channels are channels 1 to j-1 and j+1 to n. The other n-1 charging circuits are the first charging circuit B1 to the (j-1)th charging circuit B(j-1) and the (+1)th charging circuit B(j+1) to the nth charging circuit Bn.The n-1 other capacitors are the first capacitor C1 to the (j-1)th capacitor C(j-1) and the (j+1)th capacitor C(j+1) to the nth capacitor Cn. This energy withdrawal prevents parasitic emission of light energy by the other n-1 lasers of the n lasers D1 to Dn when the control CTR is closed by closing the control switch T. dis The j-th laser Dj is caused to emit a laser pulse. The control circuit CTR then, after the charging process has been completed and, additionally, only after the discharging process of the other capacitors has also been completed, preferentially switches off the j-th charging circuit Bj, or sets the charging output of the j-th charging circuits Bj to high impedance, and then closes the control switch T. disThis initiates the light pulse generation by the j-th laser (Dj) of the n lasers D1 to Dn. In contrast to the technical teaching of WO 2021 / 140 160 A1, the control circuit CTR then, after the charging process of the j-th capacitor has been completed and the discharge process of the other capacitors C1 to C(j-1) and C(j+1) and Cn has also been completed, preferably does not switch off the other charging circuits B1 to B(j-1) and B(j+1) to Bn, or preferably does not make the charging output of the other charging circuits B1 to B(j-1) and B(j+1) to Bn high-impedance. Rather, the control circuit CTR preferably does not switch off the other charging circuits B1 to B(j-1) and B(j+1) to Bn after the charging process of the j-th capacitor has been completed and the discharge process of the other capacitors C1 to C(j-1) and C(j+1) and Cn has also been completed.The charging output of the other charging circuits B1 to B(j-1) and B(j+1) to Bn is preferably not high-impedance, thus fixing the potentials of the other discharge lines K1 to K(j-1) and K(j+1) to Kn and thereby preventing parasitic light emission from the n-1 other lasers D1 to D(j-1) and D(j+1) to Dn. As in the prior art, the control circuit CTR then selects a k-th channel of the n channels with 1≤k≤n and k∈ℕ instead of the j-th channel. The control circuit CTR repeats the previously described process for this k-th channel instead of the j-th channel, and thus for the emission of a laser pulse by means of the k-th laser Dk instead of the j-th laser Dj, until all n lasers D1 to Dn have preferably emitted exactly one light pulse and then starts again from the beginning with the next cycle. CVDD decoupling capacitor for stabilizing the operating voltage VDD; D1 first laser; D2 second laser; D3 third laser; DisC first star point and contact surface for the first star point. The cathodes of lasers D1 to Dn are preferably connected to the first star point. The first star point is activated upon the arrival of a pulse signal G. dis through the control switch T dis connected to the reference potential GND. If one of the capacitors C1 to Cn has been previously charged, this capacitor is then discharged via the corresponding laser, which then emits a light pulse; DiscK second star point as common connection point of capacitors C1 to Cn; Dk k-ter laser; D(j-1) (j-1)th laser; DJ J-ter Laser; D(j+1) (j+1)th laser; Dn n-th laser; G dis Pulse signal; GND reference potential; K1 is the first charging line, via which the first charging circuit B1 charges the first capacitor C1 before a light pulse generation by the first laser D1; K1' first discharge line, through which the first laser D1 discharges the first capacitor C1 when the control switch T dis through the pulse signal G dis is closed; K2 second charging line, via which the second charging circuit B2 charges the second capacitor C2 before a light pulse generation by the second laser D2; K2' second discharge line, via which the second laser D2 discharges the second capacitor C2 when the control switch T dis through the pulse signal G dis is closed; K3 third charging line, via which the third charging circuit B3 charges the third capacitor C3 before a light pulse generation by the third laser D3; K3' third discharge line, via which the third laser D3 discharges the third capacitor C3 when the control switch T dis through the pulse signal G dis is closed; Kn n-th charging line, via which the n-th charging circuit Bn charges the n-th capacitor Cn before a light pulse generation by the n-th laser Dn; Kn' n-th discharge line, through which the n-th laser Dn discharges the n-th capacitor Cn when the control switch T dis through the pulse signal G dis is closed; LC1 Inductance of the line with which the second contact of the first capacitor C1 is connected to the reference potential; LC2 Inductance of the line with which the second contact of the second capacitor C2 is connected to the reference potential; LC3 Inductance of the line with which the second contact of the third capacitor C3 is connected to the reference potential; LCn Inductance of the line with which the second contact of the nth capacitor Cn is connected to the reference potential; LCV line inductance between the second terminal of the decoupling capacitor CVDD and the reference potential GND; LZ1 Inductance of the first charging line K1, via which the first charging circuit B1 charges the first capacitor C1 before a light pulse generation by the first laser D1; LZ2 Inductance of the second charging line K2, via which the second charging circuit B2 charges the second capacitor C2 before a light pulse generation by the second laser D2; LZ3 Inductance of the third charging line K3, via which the third charging circuit B3 charges the third capacitor C3 before a light pulse generation by the third laser D3; LZn Inductance of the nth charging line Kn, via which the nth charging circuit Bn charges the nth capacitor Cn before a light pulse generation by the nth laser Dn; LZV Line inductance of the supply line to the CVDD decoupling capacitor; PL Pulse Pre-signal; RC1 Resistance of the line with which the second contact of the first capacitor C1 is connected to the reference potential; RC2 Resistance of the line with which the second contact of the second capacitor C2 is connected to the reference potential; RC3 Resistance of the line with which the second contact of the third capacitor C3 is connected to the reference potential; RCn resistance of the line with which the second contact of the nth capacitor Cn is connected to the reference potential; RZ1 first parasitic resistance of the first charging line (K1); RCV line resistance between the second terminal of the decoupling capacitor CVDD and the reference potential GND RZ1 Resistance of the first charging line K1, via which the first charging circuit B1 charges the first capacitor C1 before a light pulse generation by the first laser D1; RZ2 Resistance of the second charging line K2, via which the second charging circuit B2 charges the second capacitor C2 before a light pulse generation by the second laser D2; RZ3 Resistance of the third charging line K3, via which the third charging circuit B3 charges the third capacitor C3 before a light pulse generation by the third laser D3; RZn resistance of the nth charging line Kn, via which the nth charging circuit Bn charges the nth capacitor Cn before a light pulse generation by the nth laser Dn; RZV Line resistance of the supply line to the CVDD backup capacitor; T dis Control switches preferably designed as transistors; VDD supply voltage; List of cited works WO 2021 / 140 160 A1 DE 10 2020 114 782 A1 DE 10 2020 124 564 A1, US 2020 / 0 178 361 A1

Claims

[1] Lidar system the lidar system includes a control circuit (CTR) and the lidar system has a plurality of charging circuits (B1 to Bn) and the lidar system uses a plurality of capacitors (C1 to Cn) and the lidar system comprises a plurality of lasers (D1 to Dn) and where n is a positive integer greater than 1 and wherein the control device CTR is set up to control the n charging circuits (B1 to Bn) and wherein the control circuit CTR is configured to cause a charging circuit of the n charging circuits (B1 to Bn), hereinafter referred to as the j-th charging circuit (Bj), to charge a capacitor of the n capacitors (C1 to Cn), hereinafter referred to as the j-th capacitor (Cj), to an energy level other than zero and wherein the control circuit (CTR) is configured to cause the other n-1 charging circuits of the n charging circuits (B1 to Bn), which are not the j-th charging circuit (Bj), to each discharge one capacitor of the other n-1 capacitors, which are not the j-th capacitor, substantially to a parasitic residual energy level, which may be zero, and wherein this charge is generated before a light pulse by a j-th laser (Dj) and wherein the control circuit (CTR) for initiating the generation of the light pulse by the j-th laser (Dj) includes a control switch (T) dis ) closes and where the closing of the control switch (T dis ) connects a common star point (DisC) with a reference potential and wherein the cathodes of the lasers (D1 to Dn) are connected to the star point (DisC) and where each of the n capacitors has a first and a second terminal and wherein the second terminal of each capacitor is connected to the reference potential and where for each of the n capacitors, the first terminal of this capacitor is connected to the anode of exactly one laser and this first terminal is not connected to any other laser or to the first terminal of any other capacitor, so that the closing of the control switch (T dis ) to a discharge of the j-th capacitor via the j-th laser (Dj) and the control switch (T dis ) by emitting a light pulse, characterized by that the control circuit (CTR) causes the other n-1 charging circuits of the n charging circuits (B1 to Bn), which are not the j-th charging circuit (Bj), to each discharge capacitor of the other n-1 capacitors, which are not the j-th capacitor, essentially to a parasitic residual energy level, which may be zero, and that these discharges occur before the generation of a light pulse by the j-th laser (Dj) and that the control circuit (CTR) measures the residual voltage of the j-th capacitor (Cj) after it has discharged, in particular by means of an analog-to-digital converter. [2] Lidar system according to claim 1, characterized by , wherein the control circuit (CTR) is configured to determine a charging time for a subsequent charging cycle of the j-th capacitor (Cj) depending on the measured residual voltage of the j-th capacitor (Cj). [3] Lidar system according to claim 1 or 2, characterized by, that the control circuit (CTR) - after the charging process of the j-th capacitor (Cj) has been completed and - after the discharge process of the other capacitors has been completed and - before closing the control switch (T dis ) switches off the j-th charging circuit (Bj) and / or switches the charging output of the j-th charging circuits (Bj) to high impedance. [4] Lidar system according to any one of claims 1 to 3, characterized by , that the control circuit (CTR) - after the charging process of the j-th capacitor (Cj) has been completed and - after the discharge process of the other capacitors has been completed and - before closing the control switch (T dis ) preferentially switches on and / or not switches off the other charging circuits (B1 to B(j-1)) and (B(j+1) to Bn) and / or switches the charging output of the other charging circuits (B1 to B(j-1)) and (B(j+1) to Bn) to low impedance. [5] Methods for operating a lidar system, where the lidar system comprises n capacitors (C1 to Cn) and where the lidar system comprises n lasers (D1 to Dn) and where n is a positive integer greater than 1 and wherein the cathodes of the lasers (D1 to Dn) are connected to the star point (DisC) and where each of the n capacitors has a first and a second terminal and wherein the second terminal of each capacitor is connected to the reference potential and where for each of the n capacitors, the first terminal of this capacitor is connected to the anode of exactly one j-th laser (Dj), and this first terminal is not connected to any other laser or to the first terminal of any other capacitor. where one of the n capacitors (C1 to Cn), hereinafter referred to as the j-th capacitor (Cj), is assigned to the j-th laser (Dj), so that the closing of the control switch (T dis ) to a discharge of the possibly previously charged j-th capacitor (Cj) via the j-th laser (Dj) and the control switch (T dis ) by emitting a light pulse through the j-th laser (Dj) when the j-th capacitor (Cj) is charged with a sufficient amount of energy, comprehensively the steps: Charging one of the n capacitors (C1 to Cn), hereinafter referred to as the j-th capacitor (Cj), to a non-zero energy level with energy prior to the generation of a light pulse by the j-th laser (Dj); and Discharging the other n-1 capacitors, other than the j-th capacitor, essentially to a parasitic residual energy level, which may be zero, in time prior to the generation of a light pulse by the j-th laser (Dj); and Closing a control switch (T dis ) to initiate the generation of the light pulse by the j-th laser (Dj), wherein the closing of the control switch (T dis ) connects the common star point (DisC) with a reference potential and Measuring the residual voltage of the j-th capacitor (Cj) after the discharge of the j-th capacitor (Cj), in particular using an analog-to-digital converter. [6] Method for operating a lidar system according to claim 5, comprising the step: Determining a charging time for a subsequent charging cycle of the j-th capacitor (Cj) as a function of the measured residual voltage of the j-th capacitor (Cj). [7] Method for operating a lidar system according to claim 5 or 6, wherein the lidar system comprises n charging circuits (B1 to Bn) for charging the n capacitors (C1 to Cn) and where the control circuit (CTR) controls the n charging circuits (B1 to Bn) and wherein each of the n capacitors (C1 to Cn) is assigned exactly one charging circuit of the n charging circuits (B1 to Bn) to discharge it or to charge it with energy to operate the laser assigned to that capacitor, with the additional step Switching off and / or switching to high impedance of the charging output of the j-th charging circuits (Bj), - which was used to charge the j-th capacitor, - after the charging process of the j-th capacitor (Cj) has been completed and - after the discharge process of the other capacitors has been completed and - before closing the control switch (Tdis ). [8] Method for operating a lidar system according to any one of claims 5 to 7, wherein the lidar system comprises n charging circuits (B1 to Bn) for charging the n capacitors (C1 to Cn) and where each of the n capacitors (C1 to Cn) is assigned exactly one laser of the n lasers (D1 to Dn) and wherein each of the n capacitors (C1 to Cn) is assigned exactly one charging circuit of the n charging circuits (B1 to Bn) to discharge it or to charge it with energy to operate the laser assigned to that capacitor, with the additional step Switching on and / or switching to low impedance of the charging output of the other n-1 charging circuits (B1 to B(j-1)) and (B(j+1) to Bn), - which were used to discharge the other capacitors (C1 to C(j-1)) and (C(j+1) to Cn), - after the charging process of the j-th capacitor (Cj) has been completed and - after the discharge process of the other capacitors has been completed and - before closing the control switch (T dis ). [9] Method for performing a transmission sequence of a lidar system according to one or more of claims 5 to 8 comprising the steps: Step 1 of the emission sequence: Selecting a j-th laser as the laser to be operated from the n lasers (D1 to Dn); and Step 2 of the emission sequence: Executing a method according to one or more of claims 4 to 6; and Step 3 of the emission sequence: If not all lasers to be operated within the emission sequence have already been operated once within the time period, - Selection of a k-th laser as the laser to be operated from the n lasers (D1 to Dn), wherein the k-th laser is different from the j-th laser and from all lasers already operated within the emission sequence, and - Repeat step 2 of the emission sequence, whereby the k-th laser is then the new j-th laser in the further course.

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