RANGING DEVICE

A ranging device is configured to emit a transmitted wave and detect a reflected wave from an object illuminated by the transmitted wave, thereby measuring a distance to the object. At least one of the transmitted wave and the reflected wave is transmitted through a transmission window. A heater is configured to heat the transmission window. A controller is configured to control energization of the heater in response to an outside temperature that is a temperature outside the ranging device and a speed of the vehicle.

CROSS REFERENCE TO RELATED APPLICATION

This international application claims the benefit of priority from Japanese Patent Application No. 2018-165989 filed with the Japan Patent Office on Sep. 5, 2018, the entire contents of which are incorporated herein by reference.

BACKGROUND

Technical Field

This disclosure relates to a ranging device.

Related Art

There is a ranging device mounted to a vehicle and configured to measure a distance to an object ahead of the vehicle. This ranging device emits transmitted waves forward, detects reflected waves of the emitted transmitted waves from the object, and thereby measures a distance to the object.

DESCRIPTION OF SPECIFIC EMBODIMENTS

In the above ranging device, a cover is provided in front of an emitter that emits transmitted waves or a detector that detects reflected waves to protect the emitter or the detector. However, snow adhering to the cover may decrease the measurement accuracy of the ranging device.

To address this issue, JP-A-1996-29535 describes that the cover of the ringing device is provided with a heater to melt the snow.

As a result of detailed research performed by the present inventors, regarding the ranging device in which the transmission window, though which transmitted waves or reflected waves are transmitted, is provided with a heater, it has been found that an energization level of the heater needed to keep the temperature of the transmission window at a desired temperature significantly differs depending on an outside temperature and a speed of the vehicle. More specifically, when the outside temperature is low, a high energization level is needed because more heat of the transmission window heated by the heater is lost to the outside air as compared with when the outside temperature is high. Even if the outside temperature is fixed, the heat of the transmission window heated by the heater is more rapidly lost when the speed of the vehicle is high as compared with when the speed of the vehicle is low, which needs a high energization level of the heater. Accordingly, if, in order to mitigate the reduction in measurement accuracy of the ranging device, the energization level is set high without exception such that snow adhering to the transmission window can be sufficiently removed under any condition, the transmission window may be unnecessarily heated by the heater, which may lead to increased power consumption by the heater.

In view of the foregoing, it is desired to have a ranging device in which a transmission window is provided with a heater, which enables appropriate control of energization of the heater.

One aspect of this disclosure provides a ranging device to be mounted to a vehicle, which is configured to emit a transmitted wave and detect a reflected wave from an object illuminated by the transmitted wave, thereby measuring a distance to the object. The ranging device includes a transmission window, a heater, and controller. at least one of the transmitted wave and the reflected wave is transmitted through the transmission window. the heater is configured to heat the transmission window. The controller is configured to control energization of the heater in response to an outside temperature that is a temperature outside the ranging device and a speed of the vehicle.

This configuration enables appropriate control of energization of the heater.

Hereinafter, some embodiments of the disclosure will be described with reference to the drawings.

1. First Embodiment

A LIDAR device100illustrated inFIG. 1is a ranging device configured to emit light as transmitted waves and detect reflected waves from an object irradiated with light, and thereby measure a distance to the object. The term “LIDAR” is an abbreviation for Light Detection and Ranging. The LIDAR device100is mounted to a vehicle and used to detect various objects ahead of the vehicle.

The LIDAR device100includes a measurer10, a heater20, and a controller30.

The measurer10includes an emitter11that emits light and a detector12that detects reflected waves of the light. The emitter11emits laser light as the light. The detector12receives the reflected waves from the object and converts the received, reflected waves into electric signals.

The measurer10is housed within the case110formed of a cover120and a case body130of the LIDAR device100illustrated inFIG. 2. The emitter11of the measurer10is housed in the upper region of a space inside the case110. On the other hand, the detector12is housed in the lower region of the space inside the case110.

A transparent transmission window121through which light is transmitted is provided as a front portion of the cover120. As used herein the term “front ” means a direction in which light is emitted from the LIDAR device100. The transmission window121provides separation between the interior and the exterior of the LIDAR device100.

The heater20is configured to heat the transmission window121from the inside of the LIDAR device100, that is, from the inner side of the transmission window121. The heater20is provided on the inner surface of the transmission window121as illustrated inFIG. 3. The heater20includes an emitter-side heater21provided on the emitter11side of the transmission window121and a detector-side heater22provided on the detector12side of the transmission window121. Each of the emitter-side heater21and the detector-side heater22has a transparent conductive film Fi and a pair of electrodes LDi, LGi, where i is 1 when belonging to the emitter-side heater21and2when belonging to the detector-side heater22. The transparent conductive film Fi is a heater film formed of a material having transparency and electrical conductivity. For example, an indium tin oxide (ITO) film is used as the transparent conductive film Fi.

The controller30may be configured as at least one microcomputer including a central processing unit (CPU), a read-only memory (ROM), a random-access memory (RAM), an input-output interface (I/O), and a bus line connecting these components. The controller30includes, as functional blocks implemented by executing programs stored in the ROM, that is, virtual elements, a distance calculator31, a target energization level determiner32, an available energization level estimator33, a control value determiner34, and a heater energizer35.

The distance calculator31is configured to use the measurer10to detect a distance to the object illuminated by the light. More specifically, the distance calculator31determines a timing at which a reflected wave is detected based on a waveform of an electrical signal received from the detector12, and calculates a distance to the object based on a time difference from emission of light. The distance calculator31may acquire information about the object, such as an azimuth of the object, in addition to the distance to the object.

The target energization level determiner32is configured to determine an energization level of the heater20(hereinafter referred to as a target energization level) in response to an outside temperature, which is a temperature outside the LIDAR device100, and a speed of the vehicle to which the LIDAR device100is mounted (hereinafter referred to as a vehicle speed). In the described later process performed by the target energization level determiner32, energization power per unit of time is acquired as the target energization level of the heater20. The target energization level determiner32acquires the outside temperature from the outside temperature sensor41mounted to the vehicle. The outside temperature sensor41is provided on the bottom of the vehicle to detect the outside temperature of the vehicle. The target energization level determiner32further acquires a vehicle speed from the vehicle speed sensor42mounted to the vehicle.

The available energization level estimator33is configured to estimate the energization level that the battery43can supply (hereinafter, also referred to as an available energization level), based on a detected battery voltage of the battery43mounted to the vehicle.

The control value determiner34is configured to determine a control value for the heater energizer35described later to control energization of the heater20. In the present embodiment, the control value is a duty cycle, which is a ratio of an energization time to a de-energization time of the heater20. The control value determiner34determines the duty cycle in response to the target energization level determined by the target energization level determiner32and the available energization level estimated by the available energization level estimator33. Since, in the present embodiment, the battery43of the vehicle is directly connected to the heater20without being connected to the heater20through a constant-voltage circuit or the like, the voltage applied to the heater20varies with variation of the battery voltage. Therefore, in response to the energization level that the battery43can currently supply, the control value determiner34determines the duty cycle such that the actual energization level of the heater20becomes the target energization level determined by the target energization level determiner32.

The heater energizer35is configured to control energization of the heater20based on the control value determined by the control value determiner34.

A determination process performed by the controller30will now be described with reference to the flowchart ofFIG. 4. The determination process ofFIG. 4is repeatedly performed every predetermined time interval after an ignition switch of the vehicle is turned on.

At S11, the controller30acquires an outside temperature from the outside temperature sensor41.

Subsequently, at S12, the controller30acquires a vehicle speed from the vehicle speed sensor42.

Subsequently, at S13, the controller30determines power W[W] to be supplied to the heater20based on the acquired outside temperature and the acquired vehicle speed. The power W is target supply power to the heater20. The target energization level determiner32is responsible for execution of S11to S13.

The power W is calculated according to the following equation (1), which is set up from the heat-transfer coefficient h [W/(m2·K)], and a predetermined target surface temperature T1[K] of the heater20minus the outside temperature T0[K].

In the equation (1), q is a heat flux [W/m2] and A is a surface area [m2] of the heater20.

The heat-transfer coefficient h is acquired using a Nusselt number Nu and a characteristic length L.

The Nusselt number Nu is a Nusselt number, assuming on-plate forced-convection which affects the top surface or the bottom surface of the case110with the LIDAR device100mounted on the vehicle.

The characteristic length L is a length along the travel direction of the vehicle, of at least a portion of the case110on the top or bottom surface of the case110. The characteristic length L may be appropriately set within a length along the travel direction on the top or bottom surface of case110. In the present embodiment, as illustrated inFIG. 5, the characteristic length L is, in a vertical cross section along the travel direction of the vehicle of the LIDAR device100, a length along the travel direction of the vehicle, of a rounded portion123connecting the top surface122of the cover120which is a portion of the case110and the front surface121aof the transmission window121. More specifically, the characteristic length L is a length along the travel direction of the vehicle, of a portion of the case110from the upper edge121bof the front surface121aof the transmission window121to the front edge122aof the top surface122of the cover120, where the length along the travel direction gradually deceases in the travel direction. This rounded portion123is a portion of the cover120of the LIDAR device100that is most susceptible to influence of a flow F of air in contact with the front surface121aof the transmission window121toward the bumper of the vehicle during travel of the vehicle.

More specifically, the heat-transfer coefficient h can be calculated according to the following equations (2) to (4).

In the equations (2) to (4), λ is the thermal conductivity of air [W/m·K], Re is the Reynolds number, and P is the Prandt1number. The Prandt1number is a ratio of the kinematic viscosity v [m2/s] to the thermal diffusion coefficient of air α [m2/s]. The Reynolds number is calculated according to the following (5).

In the above equation (5), U is a vehicle speed [m/s].

At S14, the controller30acquires a detected value of the battery voltage.

Subsequently, at S15, the controller30estimates power WO that the battery43can supply, based on the acquired, detected value of the battery voltage. The available energization level estimator33is responsible for execution of S14to S15.

Subsequently, at S16, the controller30determines a duty cycle based on the power W determined at S13and the power WO estimated at S15. Thereafter, the controller30terminates the determination process ofFIG. 4. The control value determiner34is responsible for execution of S16.

Besides the determination process ofFIG. 4, the controller30controls energization of the heater20based on the duty cycle determined in the determination process ofFIG. 4. The heater energizer35is responsible for execution of this process.

The first embodiment set forth above can provide the following advantages.

(1a) The controller30is configured to control energization of the heater20in response to the outside temperature and the vehicle speed, which enables appropriate control of energization of the heater20.

(1b) The controller30is configured to control energization of the heater20based on a function of the outside temperature and the vehicle speed as parameters, which enables optimization of the energization level of the heater20and thus enables reduction of power consumption of the heater20.

(1c) the controller30is configured to control energization of the heater20based on the detected battery voltage of the battery43as well, which enables reduction of variation of the actual energization level of the heater20with variation of the battery voltage.

2. Second Embodiment

2-1. Differences from First Embodiment

A second embodiment is similar in basic configuration to the first embodiment. Thus, duplicate description regarding the common configuration will be omitted and differences from the first embodiment will be mainly described below.

In the first embodiment, the controller30controls energization of the heater20based on a function of the outside temperature and the vehicle speed as parameters. More specifically, at S13of the determination process illustrated inFIG. 4, the controller30determines the power W to be supplied to the heater20based on the function of the outside temperature and the vehicle speed as parameters.

On the other hand, in the second embodiment, the controller30controls energization of the heater20based on a table in which an energization condition for the heater20is predefined depending on the outside temperature and the vehicle speed. More specifically, at S13of the determination process illustrated inFIG. 4, the controller30determines the power W to be supplied to the heater20with reference to an example table illustrated inFIG. 6that preliminarily associates the power W to be supplied to the heater20with the outside temperature and the vehicle speed. In the table illustrated inFIG. 6, the power W is set such that the lower the outside temperature, the higher the power W, and the higher the vehicle speed, the higher the power W.

The second embodiment enables appropriate energization of the heater20in a relatively simple process as compared with the first embodiment.

3-1. Differences from First Embodiment

A third embodiment is similar in basic configuration to the first embodiment. Thus, duplicate description regarding the common configuration will be omitted and differences from the first embodiment will be mainly described below.

The third embodiment is different from the first embodiment in that, as illustrated inFIG. 7, the controller30is configured to determine at least a snowfall condition around the vehicle based on weather information acquired from a weather information receiver44, and control energization in response to not only the outside temperature and the vehicle speed, but also the snowfall condition. The weather information receiver44receives, from an external information communication system, such as Vehicle Information and Communication System (VICS), weather information in an area including at least a location where the vehicle is traveling. VICS is a registered trademark. The weather information received by the weather information receiver44includes information regarding the snowfall in the area. The controller30determines the snowfall condition around the vehicle based on the snowfall condition in the area, such as an amount of snowfall, in the weather information acquired from the weather information receiver44.

A determination process of the third embodiment performed by the controller30instead of the determination process of the first embodiment will now be described with reference to the flowchart ofFIG. 8. The determination process ofFIG. 8is repeatedly performed every predetermined time interval after the ignition switch of the vehicle is turned on.

First, at S21, the controller30determines whether the weather information receiver44has acquired weather information in an area including a location where the vehicle is traveling.

If at S21the controller30determines that the weather information receiver44has acquired the weather information at S21, it proceeds to S22and determines whether there is snowfall in the area based on the weather information acquired by the weather information receiver44.

If at S22the controller30determines that there is no snowfall in the area, it proceeds to S23and corrects the target surface temperature T1in the above equation (1) to a target surface temperature T1aunder normal conditions where there is no snowfall, and then proceeds to S25.

On the other hand, if at S22the controller30determines that there is snowfall, the controller30proceeds to S24. At S24, the controller30corrects the target surface temperature Ti to a target surface temperature T1bunder snowfall conditions, and then proceeds to S25. The target surface temperature T1bunder snowfall conditions is higher than the target surface temperature T1aunder normal conditions such that the target surface temperature T1bunder snowfall conditions increases as the amount of snowfall increases. The controller30corrects the target surface temperature T1in response to the amount of snowfall included in the information acquired by the weather information receiver44. This is because, during snowfall, heat of the transmission window121is easily taken away by snow, so it is necessary to increase the energization level of the heater20as compared with under normal conditions where there is no snowfall. This is also because, even during snowfall, it is necessary to increase the energization level as the amount of snowfall increases.

On the other hand, if at S21the controller30determines that the weather information receiver44has not acquired the weather information, it proceeds to S25. In this case, the current value of the target surface temperature T1is kept unchanged.

Subsequently, at S25, the controller30acquires an outside temperature from the outside temperature sensor41.

Subsequent S26, S27, and S30are the same as S12, S13and S16of the first embodiment, and S28and S29performed by the controller30on another route than the route of S21to S27are the same as S14and S15of the first embodiment. Thereafter, the controller30terminates the determination process ofFIG. 8. The target energization level determiner32is responsible for execution of S21to S27. The available energization level estimator33is responsible for execution of S28to S29. The control value determiner34is responsible for execution of S30.

The third embodiment set forth above in detail can provide the following advantages in addition to the advantages of the first embodiment.

(3a) In the third embodiment, the controller30determines at least a snowfall condition around the vehicle based on weather information acquired from the weather information receiver44, and controls energization in response to not only the outside temperature and the vehicle speed, but also the snowfall condition. This enables appropriate energization of the heater20in response to the snowfall condition.

(3b) More specifically, the controller30controls energization of the heater20such that the energization level under snowfall conditions is higher than the energization level under normal conditions where there is no snowfall. Therefore, snow adhering to the transmission window121can be rapidly melted even during snowfall, which can mitigate the reduction in measurement accuracy of the LIDAR device100.

(3c) The controller30controls the energization level of the heater20in response to the snowfall condition, such as an amount of snowfall or the like. This enables energization of the heater20at an appropriate energization level to the snowfall condition.

A fourth embodiment is similar in basic configuration to the third embodiment. Thus, duplicate description regarding the common configuration will be omitted and differences from the third embodiment will be mainly described below.

In the third embodiment, the controller30determines the snowfall condition based on the weather information acquired from the weather information receiver44. On the other hand, in the fourth embodiment, the controller30determines the snowfall condition based on the outside temperature and an operating state of a windshield wiper45as illustrated inFIG. 9. More specifically, when the outside temperature is below a predetermined temperature and the windshield wiper45is in operation, the controller30determines that there is snowfall.

In addition, the controller30controls the energization level of the heater20in response to an operating state of the windshield wiper45. A wiping speed at which the windshield wiper45wipes the transmission window121can be variably set in multiple levels. When the windshield wiper45is operating at a high wiping speed level, it is considered that the amount of snowfall is high. Thus, the controller30controls energization of the heater20such that the higher the wiping speed of the windshield wiper45, the higher the energization level of the heater20.

The determination process of the fourth embodiment performed by the controller30instead of the determination process ofFIG. 8of the third embodiment is similar to the determination process of the third embodiment except in the following. More specifically, the controller30skips S21and begins the process with S22. In S22, as described above, based on the outside temperature and the operating state of the windshield wiper45, the controller30determines whether there is snowfall around the vehicle. In S24, the controller30corrects the target surface temperature T1to the target surface temperature T1bunder snowfall conditions in response to the wiping speed level of the windshield wiper45.

The fourth embodiment can provide similar advantages as in the third embodiment.

A fifth embodiment is similar in basic configuration to the third embodiment. Thus, duplicate description regarding the common configuration will be omitted and differences from the third embodiment will be mainly described below.

In the third embodiment, the controller30determines the snowfall condition based on the weather information acquired from the weather information receiver44. On the other hand, in the fifth embodiment, as illustrated inFIG. 10, the controller30determines the snowfall condition based on a result of analysis of images of the surroundings of the vehicle captured by the camera46mounted to the vehicle.

The camera46is attached to the front inside of the vehicle. The camera46repeatedly captures images of an area ahead of the vehicle every predetermined time interval and outputs data of the captured images to a vehicle-mounted ECU (not shown). The vehicle-mounted ECU detects snow from the images captured by the camera46and analyzes a snowfall condition, such as an amount of snowfall, in the surroundings ahead of the vehicle. The controller30acquires a result of analysis by the vehicle-mounted ECU and performs the process based on the acquired result of analysis.

The determination process of the fifth embodiment performed by the controller30instead of the determination process ofFIG. 8of the third embodiment is similar to the determination process of the third embodiment except in the following. More specifically, the controller30skips S21and begins the process with S22. At S22, as described above, based on a result of analysis of images captured by the camera46mounted to the vehicle, the controller30determines whether there is snowfall in the surroundings ahead of the vehicle. At S24, the controller30corrects the target surface temperature T1to the target surface temperature T1bunder snowfall conditions in response to the amount of snowfall acquired from the images captured by the camera46.

The fifth embodiment can provide similar advantages as in the third embodiment.

6. Other Embodiments

Specific embodiments of the present disclosure have been described above, but the present disclosure may be implemented in various embodiments without being limited to the above embodiments.

(6a) In the above first embodiment, a length along the travel direction of the vehicle, of a portion of the case110connecting the front surface121aof the transmission window121and the top surface122of the cover120, is used as the characteristic length L when determining the heat-transfer coefficient h, but is not limited thereto. That is, the characteristic length L, as long as it is a length along the travel direction of the vehicle, of at least a portion of the case110on the top or bottom surface of the case110, may be selected to be a length of an appropriate portion of the case110to the shape or the like of the LIDAR device100. More specifically, for example, as it is not desirable that the light transmitted by the LIDAR device100is blocked, the LIDAR device100may be mounted to the vehicle so as to protrude from the bumper of the vehicle. In such a vehicle, the characteristic length L may be a length along the travel direction of the vehicle, of a portion of the top surface or the bottom surface of the LIDAR device100, particularly, the top surface of the LIDAR device100, which protrudes from the bumper of the vehicle. This is because the portion of the LIDAR device100that protrudes from the vehicle is also considered to be susceptible to air flow that the traveling vehicle receives. Then, in cases where the length along the travel direction of the vehicle, of the portion of the LIDAR device100protruding from the vehicle, changes in the lateral direction of the vehicle, a maximum of the length may be used as the characteristic length L.

(6b) In each of the above embodiments, whether or not there is snowfall, the controller30controls energization of the heater20beforehand in response to the vehicle speed and the outside temperature. That is, the controller30may activate the heater20even if there is no snowfall. This is because it may be difficult to instantly heat the heater20if the outside temperature is too low when snow begins to fall. Thus, it is preferable to, whether or not there is snowfall, operate the heater20beforehand at an appropriate energization level.

On the other hand, from the viewpoint of suppressing power consumption, for example, the controller30may activate the heater20when determining that there is snowfall at least around the vehicle. Further, the controller30may activate the heater20only when determining that there is snowfall at least around the vehicle.

(6c) In the above embodiments, the controller30controls energization of the heater20in response to not only the outside temperature and the vehicle speed, but also the battery voltage. Alternatively, the controller30may control energization to the heater20without taking into account the battery voltage.

(6d) In the above third embodiment, as in the first embodiment, the controller30controls energization of the heater20based on the function of the outside temperature and the vehicle speed as parameters. Alternatively, as in the second embodiment, the controller30may control energization of the heater20based on a table in which an energization condition is pre-defined depending on the outside temperature and the vehicle speed.

More specifically, for example, two types of tables, in each of which an energization condition is pre-defined, may be prepared: one under snowfall conditions and the other under normal conditions where there is no snowfall. Numerical values in the table under snowfall conditions are set such that the energization level of the heater20is higher than under normal conditions. In response to determining that there is snowfall, the controller30acquires the energization condition with reference to the table under snowfall conditions. On the other hand, in response to determining that there is no snowfall, the controller30acquires the energization condition with reference to the table under normal conditions.

This also applies to the fourth and fifth embodiments.

(6e) The outside temperature used to determine the target energization level may be corrected based on a result of detection by a solar radiation sensor provided on a bottom of the vehicle carrying the LIDAR device100, or an on/off state of vehicle lights. Since the outside temperature sensor41is normally provided at a position away from the LIDAR device100, the outside temperature around the LIDAR device100and the outside temperature detected by the outside temperature sensor41may be different. More specifically, for example, in cases where the outside temperature sensor41is provided on the bottom of the vehicle where it is less susceptible to the sun, the outside temperature around the LIDAR device100may be higher than the temperature detected by the outside temperature sensor41. Therefore, in response to a result of detection by the solar radiation sensor, the outside temperature used to determine the target energization level may be corrected to be higher than the outside temperature detected by the outside temperature sensor41. In addition, when the vehicle lights are off, that is, during daylight hours, the outside temperature used to determine the target energization level may be corrected to be higher than the outside temperature detected by the outside temperature sensor41in response to the on/off state of the lights.

(6f) The outside temperature used to determine the target energization level may be corrected based on information regarding a road on which the vehicle is traveling. More specifically, for example, in cold climates, a temperature inside a tunnel is high as compared with a temperature outside the tunnel and the outside temperature drops at once upon exit from the tunnel. Thus, the transmission window121may not be heated sufficiently by the heater20and snow adhering to the transmission window121may not be melted quickly. Therefore, the controller30may be configured to, even during travel in a tunnel, determine the target energization level based on the outside temperature before the vehicle enters the tunnel.

(6g) The controller30may control the target energization level to be higher than the target energization level determined from the current vehicle speed if the vehicle speed is expected to increase rapidly. This is because it is intended to increase the energization level of the heater20beforehand taking into account that it takes time for the temperature of the heater20to rise. Specifically, the vehicle speed used to determine the target energization level may be an arrival vehicle speed estimated from the acceleration of the vehicle. In cases where the acceleration of the vehicle is equal to or higher than a predetermined value, the controller30may correct the target energization level to be higher than the target energization level determined based on the current speed. The acceleration of the vehicle can be acquired from an acceleration sensor of the vehicle. Furthermore, the target energization level may be corrected based on information regarding the road on which the vehicle will travel. More specifically, for example, since the vehicle traveling on an expressway is expected to reach a high speed, the controller30may correct the target energization level of the heater20to a high level when entering the expressway.

(6h) In the above third embodiment, the controller30may further be configured to determine whether there is contamination on the transmission window121, based on a result of detection by a contamination sensor provided on the transmission window121. If it is determined that there is no contamination on the transmission window121, then the heater20may not be activated. Even if the acquired weather information indicates that there is snowfall, there may be no snowfall in an area where the vehicle is actually traveling. If nothing is detected by the contamination sensor, there is no snow adhering to the transmission window121, and it may be considered that there is no snowfall around the vehicle. Therefore, if the controller30determines that there is no contamination, it may not activate the heater20regardless of contents of the weather information. The contamination sensor is usually used to drive a cleaning device, such as a washer, when contamination is detected.

(6i) In the above embodiments, the LIDAR device is an example of the ranging device, but the type of the ranging device is not limited to this type. More specifically, the ranging device includes, for example, a millimeter-wave radar device or an ultrasonic sensor device.

(6j) In the above embodiments, the LIDAR device100is mounted on the front side of the vehicle, but the mounting position of the LIDAR device100on the vehicle is not limited to this position. More specifically, for example, the LIDAR device100may be mounted around the vehicle, such as on the left side, the right side, or the rear side of the vehicle.

(6k) In the above embodiments, the transmission window121is a window that transmits both the transmitted waves and the reflected waves. Alternatively, the transmission window121may be configured such that at least either of the transmitted waves and the reflected waves are transmitted. In addition, in the above embodiments, the transmission window121is transparent such that light, as transmitted waves, can be transmitted. Alternatively, the transmission window121does not need to be transparent if it transmits the transmitted waves. The transmission window121can be made of various materials depending on the type of transmitted waves.

(6l) The functions of a single component may be distributed to a plurality of components, or the functions of a plurality of components may be consolidated into a single component. At least part of the configuration of the above embodiments may be replaced with a known configuration having a similar function. At least part of the configuration of the above embodiments may be removed. At least part of the configuration of one of the above embodiments may be replaced with or added to the configuration of another one of the above embodiments.

(6m) Besides the LIDAR device100described above, the present disclosure may be implemented in various modes, such as the controller30as a constituent element of the LIDAR device100, a program for causing a computer to serve as the controller30, a storage medium storing this program, and a method for controlling energization of the heater20in the LIDAR device100.