Control method, control circuit and control system for a lidar

Abstract

The present disclosure provides a control method, a control circuit, a control system and a computer readable storage medium applied to a laser radar. The laser radar comprises a laser emitting device for emitting laser and a motor for driving the movement of an optical redirection element. The control method comprises: obtaining a first signal output by a plurality of sensors at a first time; obtaining a second signal output by the plurality of sensors at a second time after the first time; in response to the second signal being different from the first signal, determining a first rotation direction of the motor based on a signal change from the first signal to the second signal; and determining whether to control the laser emitting device to stop emitting laser based on the determined first rotation direction of the motor. Through the method, the running state of the motor can be more accurately detected and the laser emitting device can be controlled, thereby enhancing the protection of the human eye.

Description

Technical Field

[0001] This disclosure relates to the field of lidar technology, and more particularly to a control method, control circuit and control system for lidar, as well as computer equipment, computer-readable storage media, computer program products, lidar and vehicle systems. Background Technology

[0002] LiDAR, short for Laser Radar, is a system for measuring distances and distances using light. It consists of a transmitting system, a receiving system, an information processing system, and a scanning system. LiDAR uses laser light as a signal source, transmitting and receiving laser light to detect the distance to a target object. Based on information such as the magnitude of reflected energy, amplitude, frequency, and phase of the reflected light spectrum, it creates a three-dimensional structural image of the target object.

[0003] The signal redirection system in a lidar system includes one or more optical redirection elements (e.g., mirrors or lenses). Driven by a motor, these optical redirection elements can guide light pulses along different paths, enabling the lidar to scan the surrounding environment. In some cases (e.g., the motor reverses or the rotor swings back and forth), if the laser emitter is not shut off in time, the light pulses emitted from the laser emitter will repeatedly illuminate the same location or area for a long time. If this location or area includes a human eye, it will cause great damage to the eye.

[0004] The methods described in this section are not necessarily methods that had been previously conceived or adopted. Unless otherwise specified, no method described in this section should be assumed to be prior art simply because it is included in this section. Similarly, unless otherwise specified, the issues mentioned in this section should not be considered to be accepted in any prior art. Summary of the Invention

[0005] This disclosure aims to at least address one of the technical problems existing in the background art. Therefore, the object of this disclosure is to provide a solution that can more accurately detect the operating status of a motor and control the laser emitting device of a lidar, thereby enhancing protection for the human eye.

[0006] According to a first aspect of the present disclosure, a control method is provided for use with a lidar system. The lidar system includes a laser emitting device for emitting laser light and a motor for driving an optical redirection element. The motor is equipped with multiple sensors for detecting the rotational position of the motor. The control method includes: acquiring a first signal output by the multiple sensors at a first moment; acquiring a second signal output by the multiple sensors at a second moment after the first moment; determining a first rotation direction of the motor based on a signal change from the first signal to the second signal, in response to the second signal being different from the first signal; and determining whether to control the laser emitting device to stop emitting laser light based on the determined first rotation direction of the motor.

[0007] According to a second aspect of the present disclosure, a control circuit is provided for use in a lidar system. The lidar system includes a laser emitting device for emitting laser light and a motor for driving an optical redirection element to move. The motor is equipped with multiple sensors for detecting the rotational position of the motor and outputting the position information as a level signal. The control circuit includes a first circuit and a second circuit, wherein the first circuit generates a signal indicating the rotational direction of the motor, and the second circuit generates a signal indicating whether the rotational speed of the motor is less than a preset speed.

[0008] According to a third aspect of the present disclosure, a control system is provided for use with a lidar system. The lidar system includes a laser emitting device for emitting laser light and a motor for driving an optical redirection element. The motor is equipped with multiple sensors for detecting the rotational position of the motor. The control system includes: a first module for acquiring a first signal output by the multiple sensors at a first moment; a second module for acquiring a second signal output by the multiple sensors at a second moment after the first moment; a third module for determining a first rotation direction of the motor based on a signal change from the first signal to the second signal in response to the second signal being different from the first signal; and a fourth module for determining whether to control the laser emitting device to stop emitting laser light based on the determined first rotation direction of the motor.

[0009] According to a fourth aspect of the present disclosure, a computer device is provided, comprising: at least one processor; and at least one memory having a computer program stored thereon, wherein, when executed by the at least one processor, the computer program causes the at least one processor to perform the method according to the first aspect described above.

[0010] According to a fifth aspect of the present disclosure, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, causes the processor to perform the method described in the first aspect above.

[0011] According to a sixth aspect of the present disclosure, a computer program product is provided, including a computer program that, when executed by a processor, causes the processor to perform the method described in the first aspect above.

[0012] According to a seventh aspect of the present disclosure, a lidar is provided, comprising: a control circuit according to the second aspect described above, a control system according to the third aspect described above, or a computer device according to the fourth aspect described above.

[0013] According to an eighth aspect of the present disclosure, a vehicle system is provided, including at least one lidar as described in the seventh aspect above.

[0014] According to one or more embodiments of this disclosure, a control method, control circuit, control system, computer device, computer-readable storage medium, computer program product, and vehicle system for use with lidar are proposed. Through this control method, control circuit, control system, computer device, computer-readable storage medium, computer program product, and vehicle system, the operating status of the motor can be detected, improving the problem of inaccurate control of the lidar's laser emitting device due to vibration or rotor oscillation at a specific angle. Attached Figure Description

[0015] The accompanying drawings exemplify embodiments and form part of the specification, serving to illustrate exemplary implementations of the embodiments together with the textual description. The illustrated embodiments are for illustrative purposes only and do not limit the scope of the claims. Throughout the drawings, the same reference numerals refer to the same elements or similar but not necessarily identical elements.

[0016] Figure 1 A schematic flowchart of a control method 10 for lidar according to an embodiment of the present disclosure is shown;

[0017] Figure 2 A schematic flowchart of a control method 10 for a lidar according to some embodiments of the present disclosure is shown;

[0018] Figure 3 A schematic flowchart of a control method 10 for a lidar according to some embodiments of the present disclosure is shown;

[0019] Figure 4 A schematic flowchart of a control method 10 for a lidar according to some embodiments of the present disclosure is shown;

[0020] Figure 5 A schematic flowchart of step S800 in a control method 10 for a lidar according to some embodiments of the present disclosure is shown.

[0021] Figure 6 A schematic diagram of a control circuit 20 applied to a lidar according to an embodiment of the present disclosure is shown; and

[0022] Figure 7 A schematic diagram of a control system 900 applied to a lidar according to an embodiment of the present disclosure is shown. Detailed Implementation

[0023] The present disclosure will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this disclosure can be combined with each other. Unless the context explicitly indicates otherwise, an element may be one or more unless the number of elements is not specifically limited. Furthermore, the numbering of steps or functional modules used in this disclosure is only for identifying each step or functional module and is not intended to limit the execution order of the steps or the connection relationship between the functional modules.

[0025] In this disclosure, unless otherwise stated, the use of terms such as "first," "second," etc., to describe various elements is not intended to limit the positional, temporal, or importance relationships of these elements; such terms are merely used to distinguish one element from another. In some examples, the first element and the second element may refer to the same instance of that element, while in other cases, based on the context, they may refer to different instances.

[0026] In this disclosure, the terminology used in the description of the various examples is for the purpose of describing particular examples only and is not intended to be limiting. Unless the context explicitly indicates otherwise, an element may be one or more unless the number of elements is specifically limited. Furthermore, the term "and / or" as used in this disclosure covers any one of the listed items and all possible combinations thereof.

[0027] In the field of lidar technology, the instantaneous power of light pulses emitted from laser emitters can reach hundreds of watts. To avoid damage to the human eye from prolonged exposure to these light pulses, related technologies typically use a counting encoder to determine whether a motor has stopped by counting the number of pulses generated within a certain time period. If the number of pulses detected within a certain time period is zero, it can generally be considered that the motor has stopped running.

[0028] However, in some situations, the encoder may still generate pulse signals even after the motor has stopped running. For example, the lidar may be subjected to external forces causing the motor rotor to vibrate, or the motor's gain parameters may be improperly set, or the load may be unbalanced, causing the rotor to swing back and forth within a specific angle range after the motor has stopped. In these cases, because the pulse signals emitted by the encoder can still be detected, the lidar's laser emitter will continue to emit laser light, potentially causing eye damage.

[0029] According to embodiments of this disclosure, a control method for lidar is proposed. This control method can detect the operating status of the motor, improving the problem of inaccurate control of the lidar's laser emitting device due to vibration or rotor oscillation within a specific angular range.

[0030] Figure 1 A schematic flowchart of a control method 10 for a lidar according to an embodiment of the present disclosure is shown. This control method 10 is applied to a lidar, which, according to an embodiment of the present disclosure, may include a laser emitting device for emitting laser light and a motor for driving the movement of an optical redirection element. The motor is equipped with multiple sensors for detecting the rotational position of the motor. Figure 1 As shown, the control method 10 for lidar may include:

[0031] S100: Acquire the first signals output by multiple sensors at the first moment;

[0032] S200: Acquire the second signal output by multiple sensors at a second time after the first time.

[0033] S300, in response to the second signal being different from the first signal, determines a first rotation direction of the motor based on the signal change from the first signal to the second signal; and

[0034] S400 determines, based on the determined first rotation direction of the motor, whether to control the laser emitting device to stop emitting laser.

[0035] According to embodiments of this disclosure, the rotation direction of the motor can be determined by the signal change from the first signal to the second signal. This allows for more accurate detection of the motor's operating status and control of the lidar's laser emitting device, thereby enhancing eye protection.

[0036] In some embodiments, the optical redirection element includes a component for redirecting the laser emitted by the laser emitter or the returning optical signal. For example, a rotating mirror in a lidar system includes an optical redirection element, or other optical elements that redirect light pulses or signals through rotational motion. This document will use a rotating mirror as an example, where a motor drives the mirror to rotate, thereby achieving horizontal scanning.

[0037] In some embodiments, the sensors mounted on the motor can be Hall sensors. For example, three Hall sensors arranged at 120-degree electrical angles apart on the motor stator can be used to detect the rotor position. It should be understood that other types of sensors or other numbers of sensors are also possible, such as photoelectric sensors or photoelectric encoders; or the number of sensors can be six (e.g., arranged at 60-degree electrical angles apart), which should not be construed as a limitation. In some embodiments, the direction of motor rotation can also be determined based on signals provided by sensors such as phase angle sensors that indicate the phase of the motor (including phase sequence and phase angle).

[0038] Figure 2 A schematic flowchart of a control method 10 for lidar according to some embodiments of the present disclosure is shown.

[0039] In some embodiments, reference Figure 2 In step S300, determining the first rotation direction of the motor based on the signal change from the first signal to the second signal may include:

[0040] S310, determine whether the signal change from the first signal to the second signal is consistent with the expected signal change, wherein the expected signal change indicates that the motor rotates in a predetermined direction; and in response to the signal change being inconsistent with the expected signal change, proceed to S320, determine that the first rotation direction of the motor is a reverse rotation opposite to the predetermined direction.

[0041] In some embodiments, signals output by multiple sensors can be sampled continuously (e.g., at a fixed frequency), with the time interval between adjacent samples typically much smaller than the time required for a motor to rotate one revolution. This allows for timely acquisition of the changed output signals when the output signals of multiple sensors change. For example, a first signal output by the sensor at a first moment is acquired, followed by a second signal output by the sensor at a second moment. This second signal is compared with the previously acquired first signal. If the second signal is inconsistent with the first signal, the change from the first signal to the second signal is further determined, as will be detailed below. Since the set sampling frequency may be high, in some cases, the signal obtained in the second sampling may be the same as the first signal. In this case, the sensor signal can continue to be acquired at that frequency.

[0042] In some embodiments, when the motor rotor rotates in one direction, the sequence of detected sensor output levels is fixed. Taking three Hall sensors arranged at 120-degree electrical angles as an example, the state of one Hall sensor changes and outputs a corresponding logic level (0 or 1) every 60-degree electrical angle the rotor travels. Therefore, the order of the sensor output level signals is constant regardless of whether the rotor rotates forward or backward. Taking normal motor operation (i.e., rotor rotating forward) as an example, the sensor output signals may have the following sequence: 101-100-110-010-011-001-101-100… Signal changes consistent with this sequence can be considered "expected signal changes," indicating that the motor is rotating in a predetermined direction. Depending on the actual needs, the sequence of sensor output signals when the rotor rotates in the opposite direction (e.g., "101-001-011-010-110-100-101-100…") can also be considered "expected signal changes."

[0043] When determining the first rotation direction of the motor, according to the above embodiment, if the first signal acquired at the first moment is 101, and the second signal acquired at the second moment is 001, then the signal change from the first signal to the second signal (i.e., 101-001) is inconsistent with the expected signal change (i.e., 101-100). At this time, the first rotation direction can be determined to be reverse rotation. Reverse rotation of the motor means that the motor has stopped running, and due to some reasons (such as vibration of the lidar or the rotor being at a specific stopping angle), the rotor swings back and forth, causing the signal output by the sensor to show the opposite order of the expected signal change.

[0044] In some embodiments, continue to refer to Figure 2 In response to the determined first rotation direction of the motor being reversed, the step can proceed to S410, controlling the laser emitting device to stop emitting laser.

[0045] Controlling the laser emitter to stop emitting laser light when the motor is detected to be rotating in the opposite direction can improve the problem of not being able to control the lidar to stop emitting laser light in time due to the rotor swinging back and forth.

[0046] In some embodiments, the duration for which the laser emitting device stops emitting laser light can also be set, for example, the laser emitting device can stop emitting laser light after a first preset time, thereby further improving safety.

[0047] In some cases, even if the initial rotation of the motor is forward, it can still cause eye damage. For example, after the motor stops rotating, the light pulse may remain in the eye for a longer period due to the slow rotation of the inertial rotor. Alternatively, when the motor rotor is oscillating back and forth, the rotor may be rotating forward at the moment sampling begins (i.e., the first instant). In these situations, because the rotor's oscillation or rotation speed is much lower than its normal operating speed, the eye may be damaged due to prolonged exposure to the light pulse. Therefore, scenarios where the motor rotates forward but at a low speed, yet still causes eye damage, need to be considered.

[0048] Figure 3 A schematic flowchart of a control method 10 for lidar according to some embodiments of the present disclosure is shown.

[0049] In some embodiments, reference Figure 3 Step S300 may further include: S310, determining whether the signal change from the first signal to the second signal is consistent with the expected signal change, wherein the expected signal change indicates that the motor rotates in a predetermined direction; and in response to the signal change being consistent with the expected signal change, the step proceeds to S330, determining that the first rotation direction of the motor is the same as the predetermined direction of rotation.

[0050] If the first rotation direction of the motor is determined to be positive, step S400 may include: S420, obtaining the first rotation speed of the motor; and S430, determining whether to control the laser emitting device to stop emitting laser based on the comparison between the first rotation speed and the first preset rotation speed.

[0051] The initial speed of the motor can be determined by a sensor used to detect the motor's rotational position (such as a Hall sensor), or by other speed detection devices; no restrictions are placed here.

[0052] In some embodiments, a first preset rotational speed can be set as a threshold for determining whether the detected first rotational speed may cause eye damage. When the first rotational direction of the motor is forward, whether to control the laser emitting device to stop emitting laser is determined by determining whether the current rotational speed of the motor is less than the preset threshold (i.e., the first preset rotational speed).

[0053] In some embodiments, if it is determined that the first rotational speed is less than the first preset rotational speed, the laser emitting device can be controlled to stop emitting laser.

[0054] By incorporating a motor speed detection step, the potential for lidar to damage the human eye can be further reduced. In some cases, the speed detection step can more quickly determine whether to stop the laser emitter, thereby shortening the response time.

[0055] In other situations, such as motor failure, the rotor may maintain a high speed, rotating for a period of time in one direction (e.g., reverse) and then for a period of time in the other direction (e.g., forward). Especially under signal interference, the rotor may continuously repeat this process. Therefore, it is also necessary to consider the problem of human eyes being damaged by repeated exposure to light pulses when the laser emitter is turned on again very shortly after being turned off, or when it is frequently switched on and off in a short period of time.

[0056] It should be understood that while in some embodiments, the stopping of the motor can be determined by detecting the motor's rotation direction as described above, thereby controlling the laser emitting device to stop emitting laser light, in other embodiments, the stopping of the motor can be determined by other methods (e.g., by measuring other physical parameters of the motor). For example, in some embodiments, the stopping of the motor can be determined by measuring the speed of the motor rotor; in other embodiments, the stopping of the motor can be determined by measuring the vibration intensity of the motor. When the vibration intensity of the motor is lower than a preset threshold intensity, it can be determined that the motor has stopped working and the laser emitting device can be controlled to stop emitting laser light.

[0057] Figure 4 A schematic flowchart of a control method 10 for lidar according to some embodiments of the present disclosure is shown.

[0058] In some embodiments, reference Figure 4 After step S410, when the laser emitting device stops emitting laser, the signal output by the sensor at the next moment can be acquired. That is, the step continues to step S500, when the third signal output by multiple sensors at the third moment is acquired; and S600, when the fourth signal output by multiple sensors at the fourth moment after the third moment is acquired.

[0059] Next, the steps can proceed to S700, in response to the fourth signal being different from the third signal, to determine the second rotation direction of the motor based on the signal change from the third signal to the fourth signal, and S800, to determine whether to control the laser emitting device to start emitting laser based on the determined second rotation direction of the motor.

[0060] In some embodiments, a method similar to that used to determine the first rotation direction described above can be used to determine the second rotation direction of the motor based on the signal change from the third signal to the fourth signal, which will not be elaborated here.

[0061] Figure 5 A schematic flowchart of step S800 in a control method 10 for lidar according to some embodiments of the present disclosure is shown.

[0062] In some embodiments, when the second rotation direction of the motor is determined to be positive rotation, reference is made. Figure 5 Step S800, based on the determined second rotation direction of the motor, determines whether to control the laser emitting device to start emitting laser, may include: S810, obtaining the second rotation speed of the motor, and S820, determining whether the second rotation speed is greater than or equal to the second preset rotation speed.

[0063] Similarly, the second speed of the motor can be determined by a sensor used to detect the motor's rotational position (such as a Hall sensor), or by other speed detection devices, without any limitation.

[0064] A second preset rotation speed can be set as a threshold for determining whether the detected second rotation speed may cause eye damage. In some embodiments, the first preset rotation speed and the second preset rotation speed can be the same value. In some embodiments, if the second rotation speed is less than the second preset rotation speed, the step proceeds to S850, keeping the laser emitting device stopped emitting laser light. At this time, since the second rotation speed has not reached the preset threshold, controlling the laser emitting device to start emitting laser light still carries the risk of eye damage. If the second rotation speed is greater than or equal to the second preset rotation speed, the step proceeds to S830: determining whether the time interval between the current moment and the moment when the controller last started controlling the laser emitting device to stop emitting laser light is greater than a second preset time.

[0065] As mentioned above, repeatedly turning the laser emitting device on and off in a short period of time may cause damage to the human eye due to repeated exposure to light pulses. Therefore, in some embodiments of this disclosure, it is necessary to further determine whether the time interval between the current moment and the moment when the controller last started controlling the laser emitting device to stop emitting laser light is greater than a second preset time. If the time interval is greater than the second preset time, the process proceeds to step S840, controlling the laser emitting device to start emitting laser light; otherwise, the process proceeds to step S850, keeping the laser emitting device stopped emitting laser light.

[0066] By setting a second preset time, the possibility of the laser emitter being turned on again in a very short time after being turned off or being repeatedly switched on and off in a short period of time can be reduced. In addition to enhancing the protection of human eyes, it can also reduce the adverse effects on the performance and lifespan of the lidar.

[0067] Figure 6 A schematic diagram of a control circuit 20 applied to a lidar according to some embodiments of the present disclosure is shown. The control circuit 20 includes a first circuit 20A and a second circuit 20B. The first circuit 20A is used to generate a signal indicating the rotation direction of a motor, and the second circuit 20B is used to generate a signal indicating whether the motor's rotational speed is less than a preset speed.

[0068] In some embodiments, the first circuit 20A may include a monostable flip-flop and at least one of the following: a D flip-flop, a complex programmable logic device, or a field-programmable gate array.

[0069] Taking the first circuit 20A, which includes a D flip-flop and a monostable multivibrator, and using a Hall sensor as an example, the output of each Hall sensor can be connected to the data input (D terminal) of a D flip-flop, while the clock input (CP terminal) of the D flip-flop can receive a signal from another Hall sensor to achieve sequential storage of Hall signals. The output (Q terminal) of the D flip-flop can be connected to the trigger terminal of the monostable multivibrator. When the state of the D flip-flop changes, the monostable multivibrator receives a trigger pulse and outputs a short level pulse to indicate a change in the rotation direction of the motor.

[0070] In some embodiments, the second circuit may include a monostable multivibrator and a duty cycle detection circuit. For example, when the sensor detects a change in the position of the motor rotor, it triggers the monostable multivibrator to generate a pulse. This pulse can be input as a PWM signal to the duty cycle detection circuit, which then determines whether the motor speed is lower than a preset threshold based on the pulse width. If the duty cycle is higher than the set value (i.e., the pulse width of the monostable multivibrator is shorter, and the speed is faster), the duty cycle detection circuit outputs a high level; if it is lower than the set value (i.e., the pulse width of the monostable multivibrator is longer, and the speed is slower), it outputs a low level, thereby indicating whether the motor speed is lower than a preset speed.

[0071] In some embodiments, the control circuit may further include logic gates, such as AND gates. The first input of the AND gate can be used to receive a signal indicating the rotation direction of the motor, and the second input can be used to receive a signal indicating whether the motor speed is less than a preset speed. The output of the AND gate can serve as the output of the control circuit, used to output a control signal to control the laser emitting device to start emitting laser light or to control the laser emitting device to stop emitting laser light.

[0072] Figure 7 A schematic diagram of a control system 900 applied to a lidar according to an embodiment of the present disclosure is shown. The control system 900 may include a first module 910, a second module 920, a third module 930, and a fourth module 940. The first module 910 is used to acquire a first signal output by multiple sensors at a first moment. The second module 920 is used to acquire a second signal output by the multiple sensors at a second moment after the first moment. The third module 930 is used to determine a first rotation direction of a motor based on the signal change from the first signal to the second signal, in response to the second signal being different from the first signal. The fourth module 940 is used to determine whether to control the laser emitting device to stop emitting laser light based on the determined first rotation direction of the motor.

[0073] In this embodiment, the specific implementation and technical effects of the control system 900 and its corresponding functional modules 910-940 applied to the lidar can be found in [reference needed]. Figures 1 to 5 The relevant descriptions in the described embodiments will not be repeated here.

[0074] According to embodiments of this disclosure, the process described above with reference to the flowchart can be implemented as a computer device, which may include a processing device (e.g., a central processing unit, a graphics processing unit, etc.) that can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) or a program loaded from a storage device into a random access memory (RAM).

[0075] According to embodiments of this disclosure, the above reference flow Figure 1 The described process can be implemented as a computer software program. For example, embodiments of this disclosure provide a computer-readable storage medium storing a computer program that includes methods for executing... Figure 1 The program code for method 10 shown. When this computer program is executed by a processing device, it implements the functions defined in the apparatus of the embodiments of this disclosure.

[0076] It should be noted that the computer-readable medium described in the embodiments of this disclosure can be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In the embodiments of this disclosure, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In the embodiments of this disclosure, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to: wires, optical fibers, RF (Radio Frequency), etc., or any suitable combination thereof.

[0077] The aforementioned computer-readable medium may be included in the aforementioned computer device; or it may exist independently and not assembled into the computer device. The aforementioned computer-readable medium carries one or more programs that, when executed by the computing device, cause the computer device to: acquire a first signal output by a sensor at a first moment; acquire a second signal output by the sensor at a second moment; in response to the second signal being different from the first signal, determine a first rotation direction of the motor based on the signal change from the first signal to the second signal; and, based on the determined first rotation direction of the motor, determine whether to control the laser emitting device to stop emitting laser light.

[0078] According to another aspect of this disclosure, a computer program product is provided, including a computer program that, when executed by a processor, causes the processor to perform the control method 10 described in any of the embodiments above.

[0079] Computer program code for performing the operations of embodiments of this disclosure can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, and conventional procedural programming languages ​​such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0080] According to another aspect of this disclosure, a lidar is provided. The lidar may include the control circuit 20, control system 900, or computer device described in any of the embodiments above. In some embodiments, the lidar according to this disclosure may include the control circuit 20 and control system 900 described in any of the embodiments above to provide redundancy for greater eye protection.

[0081] According to another aspect of this disclosure, a vehicle system is provided, including the lidar described above.

[0082] The vehicles include, but are not limited to, vehicles, drones, and ships, and their application scenarios include, but are not limited to, roadside detection devices, dock monitoring, intersection monitoring, factories, and other systems with multiple sensors.

[0083] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of methods, apparatus, and computer program products according to various embodiments of the present disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0084] The units described in the embodiments of this disclosure can be implemented in software or hardware. The described units can also be housed in a processor; for example, it can be described as a processor including a first module, a second module, a third module, and a fourth module. The names of these modules do not necessarily limit the module itself.

[0085] The following describes some exemplary solutions of this disclosure.

[0086] Option 1: A control method applied to a lidar, the lidar including a laser emitting device for emitting laser light and a motor for driving the movement of an optical redirection element, the motor being equipped with multiple sensors for detecting the rotational position of the motor, the control method including:

[0087] Acquire the first signal output by the plurality of sensors at the first moment;

[0088] Acquire the second signal output by the plurality of sensors at a second time after the first time;

[0089] In response to the second signal being different from the first signal, a first rotation direction of the motor is determined based on the signal change from the first signal to the second signal; and

[0090] Based on the determined first rotation direction of the motor, determine whether to control the laser emitting device to stop emitting laser.

[0091] Option 2: According to the control method described in Option 1, determining the first rotation direction of the motor based on the signal change from the first signal to the second signal includes:

[0092] Determine whether the signal change from the first signal to the second signal is consistent with the expected signal change, wherein the expected signal change indicates that the motor rotates in a predetermined direction; and

[0093] In response to the signal change being inconsistent with the expected signal change, the first rotation direction of the motor is determined to be a reverse rotation opposite to the predetermined direction of rotation.

[0094] Option 3: The control method described in Option 2, wherein determining whether to control the laser emitting device to stop emitting laser light based on the determined first rotation direction of the motor includes:

[0095] In response to the determined first rotation direction of the motor being reversed, the laser emitting device is controlled to stop emitting laser light.

[0096] Option 4, the control method according to Option 3, further includes:

[0097] The duration for which the laser emitting device stops emitting laser light is a first preset time.

[0098] Option 5: The control method according to any one of Options 1 to 4, wherein determining the first rotation direction of the motor based on the signal change from the first signal to the second signal includes:

[0099] Determine whether the signal change from the first signal to the second signal is consistent with the expected signal change, wherein the expected signal change indicates that the motor rotates in a predetermined direction; and

[0100] In response to the signal change being consistent with the expected signal change, the first rotation direction of the motor is determined to be a positive rotation, which is the same as the predetermined direction of rotation.

[0101] Option 6: The control method according to Option 5, wherein determining whether to control the laser emitting device to stop emitting laser light based on the determined first rotation direction of the motor includes:

[0102] In response to the determined first rotational direction of the motor being forward, a first rotational speed of the motor is obtained; and

[0103] Based on the comparison between the first rotational speed and the first preset rotational speed, it is determined whether to control the laser emitting device to stop emitting laser.

[0104] Option 7: The control method according to Option 6, wherein determining whether to control the laser emitting device to stop emitting laser based on a comparison between the first rotational speed and the first preset rotational speed includes:

[0105] In response to the first rotational speed being less than the first preset rotational speed, the laser emitting device is controlled to stop emitting laser light.

[0106] Option 8, the control method according to Option 3 or 7, further includes:

[0107] Acquire the third signal output by the plurality of sensors at the third time.

[0108] Acquire the fourth signal output by the plurality of sensors at a fourth time after the third time.

[0109] In response to the fourth signal being different from the third signal, a second rotation direction of the motor is determined based on the signal change from the third signal to the fourth signal; and

[0110] Based on the determined second rotation direction of the motor, it is determined whether to control the laser emitting device to start emitting laser.

[0111] Option 9: The control method according to Option 8, wherein determining the second rotation direction of the motor based on the signal change from the third signal to the fourth signal includes:

[0112] Determine whether the signal change from the third signal to the fourth signal is consistent with the expected signal change; and

[0113] In response to the signal change being consistent with the expected signal change, the second rotation direction of the motor is determined to be positive rotation.

[0114] Option 10: The control method according to Option 9, wherein determining whether to control the laser emitting device to start emitting laser light based on the determined second rotation direction of the motor includes:

[0115] In response to the determined second rotational direction of the motor being positive, the second rotational speed of the motor is obtained; and

[0116] Based on the comparison between the second rotation speed and the second preset rotation speed, it is determined whether to control the laser emitting device to start emitting laser.

[0117] Option 11: According to the control method described in Option 10, determining whether to control the laser emitting device to start emitting laser light based on a comparison between the second rotational speed and the second preset rotational speed includes:

[0118] In response to the second rotational speed being greater than or equal to the second preset rotational speed, determine whether the time interval between the current moment and the moment when the controller last started controlling the laser emitting device to stop emitting laser light is greater than the second preset time; and

[0119] In response to the current time being greater than or equal to the time when the controller last started controlling the laser emitting device to stop emitting laser, the laser emitting device is controlled to start emitting laser.

[0120] Option 12: A control circuit applied to a lidar, the lidar including a laser emitting device for emitting laser light and a motor for driving an optical redirection element to move, the motor being equipped with multiple sensors for detecting the rotational position of the motor and outputting the position information as a level signal, the control circuit including a first circuit and a second circuit, wherein...

[0121] The first circuit is used to generate a signal indicating the rotation direction of the motor, and

[0122] The second circuit is used to generate a signal indicating whether the motor speed is less than a preset speed.

[0123] Scheme 13: The control circuit according to Scheme 12, wherein the first circuit includes a monostable multivibrator and at least one of the following: a D flip-flop, a complex programmable logic device, or a field-programmable gate array.

[0124] Option 14: The control circuit according to Option 12 or 13, wherein the second circuit includes:

[0125] A monostable trigger, configured to generate a pulse signal in response to changes in the signal output of the plurality of sensors; and

[0126] The duty cycle detection circuit is configured to receive the pulse signal and generate a signal indicating whether the motor speed is less than a preset speed based on the duty cycle of the pulse signal width.

[0127] Option 15: A control circuit according to any one of Options 12 to 14, wherein the plurality of sensors include Hall sensors.

[0128] Option 16: A control system applied to a lidar, the lidar including a laser emitting device for emitting laser light and a motor for driving the movement of an optical redirection element, the motor being equipped with multiple sensors for detecting the rotational position of the motor, the control system including:

[0129] The first module is used to acquire the first signal output by the plurality of sensors at a first moment;

[0130] The second module is used to acquire a second signal, which is different from the first signal, output by the plurality of sensors at a second time after the first time.

[0131] The third module is used to determine the first rotation direction of the motor based on the signal change from the first signal to the second signal; and

[0132] The fourth module is used to determine whether to control the laser emitting device to stop emitting laser light based on the determined first rotation direction of the motor.

[0133] Option 17: A computer device, comprising:

[0134] At least one processor; and

[0135] At least one memory on which a computer program is stored,

[0136] When the computer program is executed by the at least one processor, it causes the at least one processor to perform the method according to any one of schemes 1 to 11.

[0137] Scheme 18: A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, causes the processor to perform the method according to any one of Schemes 1 to 11.

[0138] Option 19: A computer program product comprising a computer program that, when executed by a processor, causes the processor to perform the method according to any one of Options 1 to 11.

[0139] Option 20: A lidar, comprising:

[0140] The control circuit according to any one of claims 12 to 15, the control system according to claim 16, or the computer equipment according to claim 17.

[0141] Option 21: A vehicle system comprising at least one lidar according to Option 20.

[0142] The above description is merely a preferred embodiment of this disclosure and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in the embodiments of this disclosure is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in the embodiments of this disclosure.

Claims

1. A control method applied to a lidar, the lidar comprising a laser emitting device for emitting laser light and a motor for driving an optical redirection element, the motor being equipped with multiple sensors for detecting the rotational position of the motor, the control method comprising: Acquire the first signal output by the plurality of sensors at the first moment; Acquire the second signal output by the plurality of sensors at a second time after the first time; In response to the second signal being different from the first signal, a first rotation direction of the motor is determined based on the signal change from the first signal to the second signal; as well as Based on the determined first rotation direction of the motor, determine whether to control the laser emitting device to stop emitting laser.

2. The control method according to claim 1, wherein, Determining the first rotation direction of the motor based on the signal change from the first signal to the second signal includes: Determine whether the signal change from the first signal to the second signal is consistent with the expected signal change, wherein the expected signal change indicates that the motor rotates in a predetermined direction; and In response to the signal change being inconsistent with the expected signal change, the first rotation direction of the motor is determined to be a reverse rotation opposite to the predetermined direction of rotation.

3. The control method according to claim 2, wherein, Based on the determined first rotation direction of the motor, determining whether to control the laser emitting device to stop emitting laser light includes: In response to the determined first rotation direction of the motor being reversed, the laser emitting device is controlled to stop emitting laser light.

4. The control method according to claim 3 further includes: The duration for which the laser emitting device stops emitting laser light is a first preset time.

5. The control method according to claim 1, wherein, Determining the first rotation direction of the motor based on the signal change from the first signal to the second signal includes: Determine whether the signal change from the first signal to the second signal is consistent with the expected signal change, wherein the expected signal change indicates that the motor rotates in a predetermined direction; and In response to the signal change being consistent with the expected signal change, the first rotation direction of the motor is determined to be a positive rotation, which is the same as the predetermined direction of rotation.

6. The control method according to claim 5, wherein, Based on the determined first rotation direction of the motor, determining whether to control the laser emitting device to stop emitting laser light includes: In response to the determined first rotational direction of the motor being forward, a first rotational speed of the motor is obtained; and Based on the comparison between the first rotational speed and the first preset rotational speed, it is determined whether to control the laser emitting device to stop emitting laser.

7. The control method according to claim 6, wherein, Based on a comparison between the first rotational speed and a first preset rotational speed, determining whether to control the laser emitting device to stop emitting laser light includes: In response to the first rotational speed being less than the first preset rotational speed, the laser emitting device is controlled to stop emitting laser light.

8. The control method according to claim 3 or 7, further comprising: Acquire the third signal output by the plurality of sensors at the third time. Acquire the fourth signal output by the plurality of sensors at a fourth time after the third time. In response to the fourth signal being different from the third signal, a second rotation direction of the motor is determined based on the signal change from the third signal to the fourth signal; as well as Based on the determined second rotation direction of the motor, it is determined whether to control the laser emitting device to start emitting laser.

9. The control method according to claim 8, wherein, Determining the second rotation direction of the motor based on the signal change from the third signal to the fourth signal includes: Determine whether the signal change from the third signal to the fourth signal is consistent with the expected signal change; and In response to the signal change being consistent with the expected signal change, the second rotation direction of the motor is determined to be positive rotation.

10. The control method according to claim 9, wherein, Based on the determined second rotation direction of the motor, determining whether to control the laser emitting device to start emitting laser light includes: In response to the determined second rotational direction of the motor being positive, the second rotational speed of the motor is obtained; and Based on the comparison between the second rotation speed and the second preset rotation speed, it is determined whether to control the laser emitting device to start emitting laser.

11. The control method according to claim 10, wherein, Based on a comparison between the second rotational speed and the second preset rotational speed, determining whether to control the laser emitting device to start emitting laser light includes: In response to the second rotational speed being greater than or equal to the second preset rotational speed, determine whether the time interval between the current moment and the moment when the controller last started controlling the laser emitting device to stop emitting laser light is greater than the second preset time; and In response to determining that the time period is greater than or equal to the second preset time, the laser emitting device is controlled to start emitting laser.

12. A control circuit applied to a lidar, the lidar comprising a laser emitting device for emitting laser light and a motor for driving an optical redirection element to move, the motor being equipped with multiple sensors for detecting the rotational position of the motor and outputting the position information as a level signal, the control circuit comprising a first circuit and a second circuit, wherein, The first circuit is used to generate a signal indicating the rotation direction of the motor, and The second circuit is used to generate a signal indicating whether the motor speed is less than a preset speed.

13. The control circuit according to claim 12, wherein, The first circuit includes a monostable flip-flop and at least one of the following: a D flip-flop, a complex programmable logic device, or a field-programmable gate array.

14. The control circuit according to claim 12, wherein, The second circuit includes: A monostable trigger, configured to generate a pulse signal in response to changes in the signal output of the plurality of sensors; and The duty cycle detection circuit is configured to receive the pulse signal and generate a signal indicating whether the motor speed is less than a preset speed based on the duty cycle of the pulse signal width.

15. The control circuit according to any one of claims 12 to 14, wherein, The plurality of sensors include Hall sensors.

16. A control system applied to a lidar, the lidar comprising a laser emitting device for emitting laser light and a motor for driving an optical redirection element, the motor being equipped with a plurality of sensors for detecting the rotational position of the motor, the control system comprising: The first module is used to acquire the first signal output by the plurality of sensors at a first moment; The second module is used to acquire the second signal output by the plurality of sensors at a second time after the first time. The third module, in response to the second signal being different from the first signal, is used to determine the first rotation direction of the motor based on the signal change from the first signal to the second signal; as well as The fourth module is used to determine whether to control the laser emitting device to stop emitting laser light based on the determined first rotation direction of the motor.

17. A computer device, comprising: At least one processor; as well as At least one memory on which a computer program is stored, When the computer program is executed by the at least one processor, it causes the at least one processor to perform the method according to any one of claims 1 to 11.

18. A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, causes the processor to perform the method according to any one of claims 1 to 11.

19. A computer program product comprising a computer program that, when executed by a processor, causes the processor to perform the method according to any one of claims 1 to 11.

20. A lidar, comprising: The control circuit according to any one of claims 12 to 15, the control system according to claim 16, or the computer device according to claim 17.

21. A vehicle system comprising at least one lidar according to claim 20.

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