Active distance measuring device and active distance measuring method

Abstract

An active distance measuring device includes a detection wave transmitter, a reflection wave receiver and a controller. The detection wave transmitter is used to transmit a detection wave at a specified transmission power to be reflected to form a reflection wave. The reflection wave receiver is used to operate at a specified detection power to receive the reflection wave and generate reflection wave information. The controller is electrically connected to the detection wave transmitter and the reflection wave receiver to control the detection wave transmitter to transmit the detection wave and receive the reflection wave information, so as to obtain distance information according to the transmission state of the detection wave and the reflection wave information. The controller is further used to receive a vehicle speed signal to adjust the specified transmission power and the specified detection power according to the vehicle speed signal.

Description

Technical Field

[0001] The invention relates to a vehicle distance measuring device, in particular to an active distance measuring device and an active distance measuring method. Background Art

[0002] Existing cars have introduced active safety systems to warn drivers in advance, actively intervene in car control, or provide driving assistance while driving. Technologies related to collision avoidance include forward collision warning, automatic emergency braking, active vehicle distance maintenance and constant speed, and blind spot detection warning. Technologies related to collision avoidance are to use a detection wave transmitter to send out a detection wave and a detector to receive the reflected wave. After the system analyzes the reflected wave and obtains the distance between the object, it determines the possibility of a collision and decides whether to intervene in driving. The aforementioned detection waves include but are not limited to invisible lasers, infrared rays, and ultrasonic waves.

[0003] All subsystems on electric vehicles are operated by the power provided by the battery, including the aforementioned active safety system. The transmission, reception and analysis of detection waves all require power consumption. The continuous operation of the active safety system will consume a lot of power, resulting in a decrease in the endurance of the electric vehicle. Summary of the invention

[0004] Based on the above technical problem, the present invention proposes an active testing device and method thereof, which can effectively reduce the power consumption during distance detection.

[0005] An embodiment of the present invention provides an active distance measuring device, comprising a detection wave transmitter, a reflection wave receiver and a controller. The detection wave transmitter is used to transmit a detection wave at a specified transmission power to be reflected to form a reflection wave. The reflection wave receiver is used to operate at a specified detection power to receive the reflection wave and generate reflection wave information. The controller is electrically connected to the detection wave transmitter and the reflection wave receiver to control the detection wave transmitter to transmit the detection wave and receive the reflection wave information, so as to obtain distance information according to the transmission state of the detection wave and the reflection wave information. The controller is further used to receive a vehicle speed signal to adjust the specified transmission power and the specified detection power according to the vehicle speed signal.

[0006] In at least one embodiment, the vehicle speed signal corresponds to the vehicle speed, and the vehicle speed is positively correlated to the designated transmission power and the designated detection power.

[0007] In at least one embodiment, the active ranging device further includes a transmitter driving circuit electrically connected to the detection wave transmitter, and a controller electrically connected to the transmitter driving circuit. The controller controls the transmitter driving circuit according to the specified transmission power, so that the transmitter driving circuit drives the detection wave transmitter to transmit the detection wave at the specified transmission power.

[0008] In at least one embodiment, the controller provides corresponding reference power to the transmitter driving circuit according to the designated transmission power, so that the transmitter driving circuit drives the detection wave transmitter to transmit the detection wave at the designated transmission power.

[0009] In at least one embodiment, the active ranging device further includes a digital-to-analog converter electrically connected to the controller. The controller controls the digital-to-analog converter according to the specified transmission power, so that the digital-to-analog converter provides corresponding reference power to the transmitter driving circuit, so that the transmitter driving circuit drives the detection wave transmitter to transmit the detection wave at the specified transmission power.

[0010] In at least one embodiment, adjusting the designated transmission power includes adjusting a duty cycle of a detection wave transmitter, a transmission frequency, or a peak power of a detection wave.

[0011] In at least one embodiment, adjusting the designated detection power includes adjusting a detection frequency or a sampling frequency of the reflected wave receiver.

[0012] In at least one embodiment, the controller receives a vehicle speed increase signal, determines a predicted vehicle speed after a delay time according to the vehicle speed increase signal, and increases the designated transmission power and the designated operating frequency to correspond to the predicted vehicle speed.

[0013] In at least one embodiment, the detection wave transmitter and the reflected wave receiver are synchronized with each other using a synchronization signal.

[0014] The present invention also proposes an active ranging method, comprising: continuously receiving a vehicle speed signal related to the vehicle speed; determining a specified transmission power and a specified detection power according to the vehicle speed; transmitting a detection wave with the specified transmission power to form a reflected wave, and receiving the reflected wave with the specified detection power to obtain distance information; determining whether the vehicle speed has changed; and when the vehicle speed has changed, adjusting the specified transmission power and the specified detection power according to the changed vehicle speed.

[0015] In at least one embodiment, the active ranging method further includes, before continuously receiving a vehicle speed signal related to the vehicle speed, starting to transmit a detection wave with an initial transmission power, and receiving a reflected wave with an initial detection power.

[0016] In at least one embodiment, the active ranging method further includes: determining whether a vehicle speed increase signal is received; determining a predicted vehicle speed after a delay time based on the vehicle speed increase signal; and increasing a specified transmission power and a specified operating frequency to correspond to the predicted vehicle speed based on the predicted vehicle speed.

[0017] In at least one embodiment, the vehicle speed is positively correlated with the designated transmission power and the designated detection power.

[0018] In at least one embodiment, adjusting the designated transmission power includes adjusting a duty cycle of the detection wave, a transmission frequency, or a peak power of the detection wave.

[0019] In at least one embodiment, adjusting the designated detection power includes adjusting a detection frequency or a sampling frequency of receiving reflected waves.

[0020] Through the active distance measuring device and the active distance measuring method of the present invention, the emission of the detection wave and the reception of the reflected wave are not normally performed with a fixed power, but are dynamically adjusted according to the vehicle speed. When the vehicle is at a lower speed, the emission power of the detection wave and the detection power of the reflected wave can be timely reduced according to the vehicle speed, and increased at a high speed. Therefore, the present invention can effectively reduce the power consumption of the active distance measuring device, and can maintain the necessary distance measurement sensitivity and accuracy.

[0021] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments, but is not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 4 is a circuit block diagram of an active distance measuring device in an embodiment of the present invention.

[0023] Figure 2 Schematic diagram of the use of an active distance measuring device in an embodiment of the present invention.

[0024] Figure 3 as well as Figure 4 It is a schematic diagram of adjusting the designated transmission power and the designated detection power in an embodiment of the present invention.

[0025] Figure 5 4 is another circuit block diagram of the active distance measuring device in an embodiment of the present invention.

[0026] Figure 6 as well as Figure 7 It is a flow chart of an active ranging method in an embodiment of the present invention.

[0027] Reference numerals

[0028] 100: Active distance measuring device

[0029] 110: Detection Wave Transmitter

[0030] 120: Reflected wave receiver

[0031] 130: Transmitter drive circuit

[0032] 140: Controller

[0033] 150: Digital to Analog Converter

[0034] 210:Automotive Electronic Control Unit

[0035] 200:Car

[0036] 300:Object

[0037] D: Detection wave

[0038] R: reflected wave

[0039] S110~S180: Steps DETAILED DESCRIPTION

[0040] The structural principle and working principle of the present invention are described in detail below in conjunction with the accompanying drawings:

[0041] The terms "module", "controller", and "driver circuit" used in the following description refer to application-specific integrated circuits (ASICs), electronic circuits, microprocessors, chips, and circuit designs that execute one or more software or firmware programs. Modules are configured to perform various algorithms, transformations, and / or logical processing to generate one or more signals. When modules, servers, and services are implemented in software, modules can be implemented in memory as program codes that can be read by chips and circuit designs and executed through program code execution.

[0042] like Figure 1 As shown, an active distance measuring device 100 provided by an embodiment of the present invention includes a detection wave transmitter 110, a reflection wave receiver 120, a transmitter driving circuit 130 and a controller 140. The controller 140 can be a system on a chip (SoC), and the controller 140 can be an independent module or a part of an on-board unit (OBU). The controller 140 is electrically connected to the electronic control unit 210 (ECU) of the vehicle to receive the vehicle speed status. The aforementioned vehicle speed status includes a vehicle speed signal and a vehicle speed increase signal. The various components of the aforementioned active distance measuring device 100 are directly or indirectly electrically connected to the power system of the vehicle 200 to obtain operating power. When the vehicle 200 is an electric vehicle, the aforementioned power comes from the battery of the vehicle 200; when the vehicle 200 is a fuel vehicle or a hybrid vehicle, the aforementioned power can come from a generator.

[0043] like Figure 1 as well as Figure 2 As shown, the detection wave transmitter 110 is installed on the surface of the car 200 and points to a specific direction; the specific direction can also be continuously changed, for example, the detection wave transmitter 110 continuously rotates 360 degrees in a plane at a fixed speed. The detection wave transmitter 110 can be installed at the front bumper, the hood, the roof or the rearview mirror, and is used to transmit the detection wave D in a specific direction with a specified transmission power, so as to be reflected by the object 300 to form a reflected wave R.

[0044] like Figure 1 as well as Figure 2 As shown, the reflected wave receiver 120 is installed on the surface of the car 200 and points to the aforementioned specific direction. Specifically, the reflected wave receiver 120 is directed toward the range where the detection wave transmitter 110 transmits the detection wave D and operates at a specified detection power to receive the reflected wave R and generate reflected wave information.

[0045] like Figure 1 As shown, the transmitter driving circuit 130 is electrically connected to the detection wave transmitter 110 to drive the detection wave transmitter 110 to transmit the detection wave D at a specified transmission power. The controller 140 is electrically connected to the automotive electronic control unit 210, the transmitter driving circuit 130 and the reflected wave receiver 120, and is indirectly electrically connected to the detection wave transmitter 110 through the transmitter driving circuit 130.

[0046] like Figure 1 as well as Figure 2 As shown, the controller 140 receives the vehicle speed signal from the automobile electronic control unit 210 to determine the designated transmission power and the designated detection power according to the vehicle speed signal. The controller 140 controls the transmitter driving circuit 130 according to the designated transmission power to drive the detection wave transmitter 110 to transmit the detection wave D at the designated transmission power; the controller 140 also controls the reflected wave receiver 120 to operate at the designated detection power. According to the transmission state of the detection wave D and the reflected wave information, such as the time difference between transmission and reception, the controller 140 can obtain the distance information from the automobile 200 to the object 300, and transmit it to the automobile electronic control unit 210 or the vehicle information unit for the active safety system to make a judgment and execute necessary intervention measures.

[0047] See also Figure 1 as well as Figure 2 As shown, the vehicle speed signal corresponds to the current vehicle speed of the vehicle 200. Assume that the vehicle speed varies between a first speed and a second speed, and the first speed is greater than the second speed. When the vehicle 200 is traveling at the first speed, braking or avoidance must be performed early to avoid collision; at this time, the effective detection distance of the active distance measuring device 100 must be increased to detect the object 300 at a longer distance; the response speed of the active distance measuring device 100 must also be increased to cope with the rapid change of distance to avoid too large a detection window. When the vehicle 200 is traveling at a lower second speed, the measures to avoid collision can be postponed; at this time, the effective detection distance of the active distance measuring device 100 can be reduced to detect the object 300 at a longer distance; because the change of distance is slower, the response speed can also be reduced. At the same time, at the first speed, the accuracy of the active distance measuring device 100 must also be higher to cope with the rapid change of distance, whereas at the second speed, the accuracy can be reduced.

[0048] See also Figure 3 as well as Figure 4 As shown, the effective detection distance is determined by the designated transmission power of the detection wave transmitter 110 and the designated detection power of the reflected wave receiver 120. Specifically, the higher the transmission cycle, i.e., the duty cycle, of the detection wave transmitter 110, the more the detection wave D can form a reflected wave R of sufficient strength at a long distance. Adjusting the designated transmission power mainly involves adjusting the duty cycle, transmission frequency, and peak power of the detection wave D. The aforementioned duty cycle can be adjusted between 0% and 100%. At 0%, the detection wave transmitter 110 is turned off and the detection distance is stopped. However, the detection wave transmitter 110 and the reflected wave receiver 120 are usually not turned off when the car 200 is started. The detection wave transmitter 110 is turned on after the car 200 is started. When the vehicle speed is zero, a duty cycle greater than 0% is still set, and an initial transmission power is used as the designated transmission power when the vehicle speed is zero to start the detection wave transmitter 110. In addition to adjusting the duty cycle, adjusting the specified transmission power may also be adjusting the driving voltage or driving current of the detection wave transmitter 110 to change the transmission frequency and peak power of the detection wave D, or adjusting the duty cycle, transmission frequency and peak power simultaneously.

[0049] Taking the first vehicle speed and the second vehicle speed as an example, at the first vehicle speed, the controller 140 controls the transmitter driving circuit 130 with a higher first transmission power to drive the detection wave transmitter 110 to transmit the detection wave D with the first transmission power. Figure 3 As shown, the duty cycle of the detection wave transmitter 110 will be increased to strengthen the strength of the detection wave D. At the second vehicle speed, the controller 140 controls the transmitter driving circuit 130 with a lower second transmission power to drive the detection wave transmitter 110 to transmit the detection wave D with the second transmission power. Figure 4 As shown, the duty cycle of the detection wave transmitter 110 will be reduced to lower the intensity of the detection wave D.

[0050] like Figure 1 As shown, specifically, the controller 140 may have a built-in digital-to-analog conversion function to provide a corresponding reference power (reference voltage or reference current) to the transmitter driving circuit 130 according to the specified transmission power, so that the transmitter driving circuit 130 drives the detection wave transmitter 110 to transmit the detection wave D at the specified transmission power.

[0051] like Figure 5As shown, when the controller 140 does not have a digital-to-analog conversion function, a digital-to-analog converter 150 may be provided and electrically connected to the controller 140. The transmitter driving circuit 130 is electrically connected to the digital-to-analog converter 150, and is indirectly electrically connected to the controller 140. The controller 140 controls the digital-to-analog converter 150 according to the specified transmission power, so that the digital-to-analog converter 150 provides the corresponding reference power to the transmitter driving circuit 130, so that the transmitter driving circuit 130 drives the detection wave transmitter 110 to transmit the detection wave D at the specified transmission power.

[0052] See also Figure 3 as well as Figure 4 As shown, the effective detection distance is also related to the detection frequency (modulation frequency) of the reflected wave receiver 120. The higher the detection frequency, the higher the sensitivity of the reflected wave receiver 120, and the more it can detect the reflected wave R transmitted from a long distance. The response rate is related to the sampling frequency (frame rate) of the reflected wave receiver 120. The higher the sampling frequency, the faster the response of the reflected wave receiver 120, and the more it can respond to the rapid change of the distance. Adjusting the specified detection power includes adjusting the detection frequency and sampling frequency of receiving the reflected wave R. Specifically, the controller 140 and the reflected wave receiver 120 can be connected through a bidirectional interface such as I2C, so that the controller 140 can adjust the specified detection power and receive the detection results transmitted back by the reflected wave receiver 120 at the same time.

[0053] Taking the first vehicle speed and the second vehicle speed as an example, at the first vehicle speed, the controller 140 controls the reflected wave receiver 120 to operate at a higher first detection power. Figure 3 As shown in FIG. 1 , the detection frequency will be increased to improve the sensitivity of the reflected wave receiver 120; at the same time, the sampling frequency is also increased to speed up the response of the reflected wave receiver 120. At the second vehicle speed, the controller 140 controls the reflected wave receiver 120 to operate at a lower second detection power. Figure 4 As shown, the detection frequency will be reduced, thereby reducing the sensitivity of the reflected wave receiver 120; at the same time, the sampling frequency is also reduced, which reduces the response rate of the reflected wave receiver 120. Generally speaking, the current speed of the car 200 is positively correlated with the specified transmission power and the specified detection power; the higher the current speed of the car 200, the higher the specified transmission power and the specified detection power; the lower the current speed of the car 200, the lower the specified transmission power and the specified detection power.

[0054] The following further describes a specific combination of the detection wave transmitter 110 and the reflected wave receiver 120 .

[0055] Taking Lidar as an example, the detection wave transmitter 110 has an array formed by a plurality of transmitting units, and the reflection wave receiver 120 has an array formed by a plurality of receiving units. The Lidar rotates 360 degrees at a certain speed to perform a 360-degree scan on each direction of the car 200.

[0056] In a laser radar, there are two parameters that can adjust the transmission power of the detection wave D; one is to adjust the driving current or voltage of the detection wave transmitter 110 to switch the peak power of the detection wave D (invisible laser); the other is to adjust the transmission frequency of the detection wave D. The higher the transmission frequency, the higher the transmission power, and the lower the frequency, the lower the transmission power. In a laser radar, usually only the detection frequency of the reflected wave R can be adjusted to change the detection power of the reflected wave receiver 120, and the detection frequency must match the transmission frequency. The sampling frequency is related to the rotation speed of the laser radar. The laser radar can complete a sampling (frame) every 360 degrees of rotation, and the detection frequency is related to the number of points that can be detected every 360 degrees of rotation of the laser radar.

[0057] Therefore, the overall detection frequency of the laser radar can be the detection frequency of the reflected wave receiver 120 multiplied by the rotation speed of the laser radar; for example, the reflected wave receiver 120 can detect 1000 points every time the laser radar rotates 360 degrees, and the laser radar rotates 20 times per second, then the overall detection frequency of the laser radar is 20KHz; the reflected wave receiver 120 can detect 720 points every time the laser radar rotates 360 degrees, and the laser radar rotates 5 times per second, then the overall detection frequency of the laser radar is 3.6KHz. The higher the detection frequency of the reflected wave receiver 120 (the denser the detection points), the smaller or more precise the object 300 that the laser radar can detect, and the higher the rotation speed of the laser radar, the faster it can respond to environmental changes, and it is suitable for the situation where the speed of the car 200 is high; on the contrary, the lower the detection frequency of the reflected wave receiver 120, the lower the rotation speed of the laser radar is suitable for the situation where the speed of the car 200 is low, and the power consumption of the laser radar can be reduced.

[0058] Taking a three-dimensional time-of-flight sensor (3DToF) as an example, in the time-of-flight sensor, there are two parameters that can adjust the transmission power of the detection wave D; one is to adjust the driving current or voltage of the detection wave transmitter 110 to switch the peak power of the detection wave D (invisible laser); the second is to adjust the transmission frequency of the detection wave D. The higher the transmission frequency, the higher the transmission power, and the lower the frequency, the lower the transmission power. In the time-of-flight sensor, usually only the detection frequency of the received reflected wave D can be adjusted to change the detection power of the reflected wave receiver 120, and the detection frequency must match the transmission frequency.

[0059] The reflected wave receiver 120 can obtain X×Y depth values ​​at each sampling. The time-of-flight ranging sensor measures distance based on the time of light flight, so the speed of light (the speed of light is a constant) multiplied by the time consumed is the distance. The inverse ratio of time is the detection frequency. The higher the detection frequency, the shorter the time, the smaller the distance unit that can be detected, and the more precise the detected object 300. Therefore, when the detection frequency is 20Mhz, the accuracy is 300,000 kilometers / 20Mhz=15 meters; when the detection frequency is 10MHz, the accuracy is 300,000 kilometers / 10MHz=30 meters. A car traveling at 100 kilometers per hour travels 27.78 meters per second. When the car 200 travels at 100 kilometers per hour, if a detection frequency of 10 MHz is used to detect the distance, the accuracy may not be enough to accurately determine the object 300. At this time, the detection frequency needs to be increased to 20 MHz, and the driving power of the detection wave transmitter 110 needs to be increased to increase the peak power of the detection so that a reflection wave R with sufficient strength can still be generated at a longer distance. On the contrary, when the car 200 travels at 50 kilometers per hour, a detection frequency of 10 MHz can be used to detect the distance.

[0060] In addition, in different combinations of detection wave transmitters 110 and reflected wave receivers 120, the adjustable parameters are also different. For example, the transmission frequency and detection frequency of ultrasonic waves and radar waves cannot be adjusted, but the driving power of the detection wave transmitter 110 and the sampling frequency of the reflected wave receiver 120 can be adjusted, and the specified transmission power and the specified detection power can also be adjusted.

[0061] See also Figure 1 As shown, the vehicle speed state may also include a vehicle speed boost signal, which may be a throttle signal or an acceleration detector signal, and is used to determine the current acceleration of the vehicle 200. The throttle signal and the acceleration detector signal may also be obtained by the vehicle electronic control unit 210. The controller 140 obtains the current acceleration according to the vehicle speed boost signal, and determines the predicted vehicle speed after the hysteresis time, and pre-increases the specified transmission power and the specified operating frequency to correspond to the predicted vehicle speed.

[0062] like Figure 4As shown, when the car 200 is running at the second speed, the detection wave transmitter 110 and the reflected wave receiver 120 work at the second transmission power and the second detection power respectively. At this time, if the driver steps on the accelerator to accelerate the car 200, the controller 140 can receive the accelerator signal and the acceleration detector signal from the car electronic control unit 210, calculate and obtain the current acceleration of the car 200, and determine that the vehicle speed will reach the first vehicle speed after the delay time. At this time, the controller 140 first controls the transmitter driving circuit 130 with the first transmission power to drive the detection wave transmitter 110 to transmit the detection wave D with the first transmission power; at the same time, the controller 140 controls the reflected wave receiver 120 to operate with the first detection power.

[0063] The aforementioned hysteresis time is mainly to match the hysteresis when the detection wave transmitter 110 and the reflected wave receiver 120 switch the power, so as to avoid that the power of the detection wave transmitter 110 and the reflected wave receiver 120 cannot be increased in real time after the vehicle speed increases.

[0064] like Figure 1 , Figure 3 as well as Figure 4 As shown, in order to make the transmission frequency of the detection wave transmitter 110 and the sampling frequency of the reflected wave receiver 120 consistent and to make the working cycle and the sampling cycle overlap, the detection wave transmitter 110 and the reflected wave receiver 120 are further connected by a synchronization signal line to transmit a synchronization signal. The reflected wave receiver 120 transmits a synchronization signal to the detection wave transmitter 110 every time it starts sampling, so as to trigger the detection wave transmitter 110 to start its working cycle to transmit the detection wave D. The synchronization signal can also be transmitted from the detection wave transmitter 110 to the reflected wave receiver 120 in reverse, so that the transmission frequency and the sampling frequency are synchronized, that is, when the detection wave transmitter 110 starts its working cycle, it transmits a synchronization signal to the reflected wave receiver 120 so that the reflected wave receiver 120 starts sampling. Alternatively, the synchronization signal can also come from an external oscillator and be transmitted to the detection wave transmitter 110 and the reflected wave receiver 120 at the same time.

[0065] See also Figure 6 As shown, based on the above active distance measurement device 100, the present invention further proposes an active distance measurement method.

[0066] like Figure 6As shown, after the car 200 is started, the controller 140 activates the detection wave transmitter 110 and the reflected wave receiver 120 with an initial transmission power and an initial detection power, and starts to transmit the detection wave D and receive the reflected wave R, so as to obtain the distance information according to the transmission state of the detection wave and the reflected wave information, as shown in step S110. At this time, the controller 140 can start to provide collision warning, and even if the car 200 is in a parked state, it can provide collision warning for possible rear-end collision events.

[0067] like Figure 6 As shown, the controller 140 then continues to receive the vehicle speed signal related to the vehicle speed and the vehicle speed increase signal related to the vehicle speed increase from the vehicle electronic control unit 210 to determine whether the vehicle speed changes according to the vehicle speed signal, as shown in step S120.

[0068] like Figure 6 As shown, when the vehicle speed changes, the controller 140 determines the transmission power and the designated detection power according to the changed vehicle speed, as shown in step S130. The controller 140 controls the detection wave transmitter 110 to transmit the detection wave D with the designated transmission power to form the reflected wave R, and controls the reflected wave receiver 120 to receive the reflected wave R with the designated detection power, so that the controller 140 continuously obtains the distance information through the transmission and reception of the detection wave D and the reflected wave R, as shown in step S140, and then returns to step S120, or continues to execute other steps. If step S120 determines that the changed vehicle speed is zero, the designated transmission power and the designated detection power are the initial transmission power and the initial detection power in step S110.

[0069] See also Figure 6 as well as Figure 7 As shown, since the vehicle speed state may also include a vehicle speed increase signal, the vehicle speed increase signal may be a throttle signal or an acceleration detector signal, which is used to determine the current acceleration of the vehicle 200, thereby determining the predicted vehicle speed after the delay time. Therefore, after determining that the vehicle speed has not changed in step S120, the following steps may be added.

[0070] like Figure 7 As shown, the controller 140 determines whether a vehicle speed increase signal is received, as shown in step S150.

[0071] The aforementioned throttle signal and acceleration detector signal can also be obtained by the automotive electronic control unit 210. The controller 140 obtains the current acceleration according to the vehicle speed increase signal and determines the predicted vehicle speed after the hysteresis time, as shown in step S160. The controller 140 then pre-increases the specified transmission power and the specified operating frequency according to the predicted vehicle speed to correspond to the predicted vehicle speed, as shown in step S170. The controller 140 waits for the hysteresis time, as shown in step S180, and then returns to step S120. The aforementioned hysteresis time is mainly to match the hysteresis when the detection wave transmitter 110 and the reflected wave receiver 120 switch the power, so as to avoid the power of the detection wave transmitter 110 and the reflected wave receiver 120 not being able to be increased in real time after the vehicle speed increases.

[0072] Through the active distance measuring device 100 and the active distance measuring method of the present invention, the emission of the detection wave D and the reception of the reflected wave R are not normally performed with a fixed power, but are dynamically adjusted according to the vehicle speed. When the vehicle 200 is at a lower speed, the emission power of the detection wave D and the detection power of the reflected wave R can be timely reduced according to the vehicle speed, and increased at a high speed. Therefore, the present invention can effectively reduce the power consumption of the active distance measuring device 100, and can maintain the necessary distance measurement sensitivity and accuracy.

[0073] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. An active distance measuring device, characterized in that: Include: a detection wave transmitter, used to transmit a detection wave at a specified transmission power to be reflected to form a reflected wave; a reflected wave receiver, used to operate at a specified detection power to receive the reflected wave and generate reflected wave information; as well as A controller is electrically connected to the detection wave transmitter and the reflected wave receiver to control the detection wave transmitter to transmit the detection wave and receive the reflected wave information, so as to obtain distance information according to a transmission state of the detection wave and the reflected wave information; wherein the controller is further used to receive a vehicle speed signal to adjust the specified transmission power and the specified detection power according to the vehicle speed signal; wherein the controller is used to receive a vehicle speed increase signal, and determine a predicted vehicle speed after a delay time according to the vehicle speed increase signal, and increase the specified transmission power and the specified operating frequency to correspond to the predicted vehicle speed.

2. The active distance measuring device according to claim 1, characterized in that: in, The vehicle speed signal corresponds to a vehicle speed, and the vehicle speed is positively correlated to the designated transmission power and the designated detection power.

3. The active distance measuring device according to claim 1, characterized in that: It further includes a transmitter driving circuit electrically connected to the detection wave transmitter, and the controller is electrically connected to the transmitter driving circuit. The controller controls the transmitter driving circuit according to the specified transmission power so that the transmitter driving circuit drives the detection wave transmitter to transmit the detection wave at the specified transmission power.

4. The active distance measuring device according to claim 3, characterized in that: in, The controller provides a corresponding reference power to the transmitter driving circuit according to the designated transmission power, so that the transmitter driving circuit drives the detection wave transmitter to transmit the detection wave at the designated transmission power.

5. The active distance measuring device according to claim 3, characterized in that: It further includes a digital-to-analog converter electrically connected to the controller; wherein the controller controls the digital-to-analog converter according to the specified transmission power so that the digital-to-analog converter provides a corresponding reference power to the transmitter driving circuit, so that the transmitter driving circuit drives the detection wave transmitter to transmit the detection wave at the specified transmission power.

6. The active distance measuring device according to claim 1, characterized in that: in, Adjusting the designated transmission power includes adjusting a duty cycle of the detection wave transmitter, a transmission frequency, or a peak power of the detection wave.

7. The active distance measuring device according to claim 1, characterized in that: in, Adjusting the designated detection power includes adjusting a detection frequency or a sampling frequency of the reflected wave receiver.

8. The active distance measuring device according to claim 1, characterized in that: in, The detection wave transmitter and the reflected wave receiver are synchronized with each other by a synchronization signal.

9. An active ranging method, characterized in that: Include: Continuously receiving a vehicle speed signal related to a vehicle speed; Determining a designated transmission power and a designated detection power according to the vehicle speed; Transmitting a detection wave with the designated transmission power to form a reflected wave, and receiving the reflected wave with the designated detection power to obtain distance information; Determine whether the vehicle speed has changed; When the vehicle speed changes, adjusting the designated transmission power and the designated detection power according to the changed vehicle speed; Determining whether a vehicle speed increase signal is received; Determining a predicted vehicle speed after a delay time according to the vehicle speed increase signal; and The designated transmission power and the designated operating frequency are increased according to the predicted vehicle speed to correspond to the predicted vehicle speed.

10. The active ranging method according to claim 9, characterized in that: It further includes, before continuously receiving the vehicle speed signal related to the vehicle speed, starting to transmit the detection wave with an initial transmission power, and receiving the reflected wave with an initial detection power.

11. The active ranging method according to claim 9, wherein: in, The vehicle speed is positively correlated to the designated transmission power and the designated detection power.

12. The active ranging method according to claim 9, characterized in that: in, Adjusting the designated transmission power includes adjusting a duty cycle of the detection wave, a transmission frequency, or a peak power of the detection wave.

13. The active ranging method according to claim 9, characterized in that: in, Adjusting the designated detection power includes adjusting a detection frequency or a sampling frequency for receiving the reflected wave.

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