Self-propelled cleaner

Abstract

Disclosed is a self-propelled cleaner that can reduce power consumption and that is economically advantageous. The self-propelled cleaner normally detects an intruder using pyroelectric sensors that consume less power, and each time a predetermined period of time has passed, detects an intruder with the infrared CCD sensor while turning the body BD. This can reduce the time of operation during which the infrared CCD sensor consuming more power is used, thus making it possible to reduce power consumption. Moreover, since the self-propelled cleaner is designed to cause the drive mechanism provided therein to turn the body BD, it is not necessary to additionally provide a device to turn the infrared CCD sensor, thus reducing the manufacturing cost.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a self-propelled cleaner including a body with a cleaning mechanism, and a drive mechanism to steer and drive the body.

2. Description of the Prior Art

Conventionally, there is known a self-propelled cleaner that is equipped with a human sensors such as a pyroelectric sensor to detect infrared rays emitted from a human body and that is configured to enable detection of a human located in the vicinity of the self-propelled cleaner (refer to, for example, Japanese Patent Laid-open numbers 02-7930 and 04-261632). A self-propelled cleaner equipped with such a human sensor can also be functioned as a security device to detect an intruder.

However, the above-mentioned human sensor has a problem that its detectable range is narrow and therefore it is impossible to detect an intruder who is not in the vicinity. Accordingly, it has been proposed that a camera with wide detection range be provided in a self-propelled cleaner.

Such a camera, however, consumes large amount of electric power and therefore it is not economical to take images with the camera over the whole period during which the user is absent. Furthermore, if the self-propelled cleaner is battery-operated it is necessary to provide a large capacity battery, resulting in an increase in the manufacturing cost.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above problems, and therefore an object of the invention is to provide a self-propelled cleaner that can reduce power consumption and is economically advantageous.

In order to achieve the above object, one aspect of the present invention resides in a self-propelled cleaner which includes: a body with a cleaning mechanism; a drive mechanism to steer and drive the body; a plurality of human sensors to detect infrared rays emitted by a human body; and a camera. The self-propelled cleaner is designed to include an intruder detection processor that causes the human sensors to detect the infrared rays from the human body, with the image taking function of the camera disabled, and each time predetermined conditions are satisfied, controls the drive mechanism to turn the body and causes the camera to take images.

According to the aspect, the self-propelled cleaner includes: a body with a cleaning mechanism; a drive mechanism to steer and drive the body; a plurality of human sensors to detect infrared rays emitted by a human body; and a camera.

The self-propelled cleaner is further equipped with an intruder detection processor that causes the human sensors to detect the infrared rays from the human body, with the image taking function of the camera disabled, and each time predetermined conditions are satisfied, controls the drive mechanism to turn the body and causes the camera to take images. That is, the detection of an intruder is normally performed with the human sensors that operate at low voltages, and the camera with wider detection range takes over at a predetermined timing. This makes it possible to reduce power consumption compared with when the camera takes images all the time, thereby implementing a more economical self-propelled cleaner. Moreover, since the self-propelled cleaner is designed to cause its drive mechanism to turn the body, no additional device is required to turn the camera, thus reducing the manufacturing cost.

For the cleaning mechanism provided in the body, a suction type, a brush type, or a combination of both types may be employed. Also, for the drive mechanism for steering and driving the body, it is possible to move the body forward and backward, turn left and right, and turn at the same position. Of course, one or more auxiliary wheels may be provided at the front and/or back of the body. Also, the drive wheel may be implemented by driving an endless belt instead of driving a wheel. In addition, the drive mechanism may be implemented by various configurations such as four-wheels or six-wheels.

As described above, according to the aspect of the present invention, it is possible to reduce the power consumption and manufacturing cost.

In another aspect of the present invention, the intruder detection processor is designed to control the drive mechanism to cause the camera to take images while turning the body, each time a predetermined period of time has passed.

This aspect of the present invention allows the camera to take images while turning the body each time a predetermined period of time has passed.

In still another aspect of the present invention, the intruder detection processor controls the drive mechanism to cause the camera to take images while turning the body, each time the value of a random number extracted at regular time intervals matches a predetermined value.

This aspect of the present invention allows turning the body and taking images by the camera to be performed at random time intervals.

In yet another aspect of the present invention, the detection of infrared rays by the human sensors is disabled while the intruder detection processor causes the camera to take images.

This aspect of the present invention disables the human sensors while the camera is taking images, and therefore power consumption can be further reduced.

In another aspect of the present invention, the camera is an infrared camera.

This aspect of the present invention allows the camera to take images of an intruder even-at night, thus making the security by the self-propelled cleaner more effective.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an external perspective view of a self-propelled cleaner of the present invention;

FIG. 2 is a rear view of the self-propelled cleaner shown in FIG. 1;

FIG. 3 is a block diagram illustrating the configuration of the self-propelled cleaner shown in FIGS. 1 and 2;

FIG. 4 is a flowchart showing the flow of the main process;

FIG. 5 is a flowchart showing the flow of the monitoring mode performing process that is invoked and executed at step S140 in the flowchart of FIG. 4;

FIG. 6 is a schematic diagram showing the operation of the self-propelled cleaner when the steps in the flowchart of FIG. 5 are performed; and

FIG. 7 is a schematic diagram showing the operation of the self-propelled cleaner when the steps in the flowchart of FIG. 5 are performed.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 is an external perspective view of a self-propelled cleaner according to the present invention, and FIG. 2 is a rear view of the self-propelled cleaner shown in FIG. 1. In FIG. 1, the direction shown by the arrow A is the direction in which the self-propelled cleaner travels. As shown in FIG. 1, the self-propelled cleaner 10 has a rough cylindrical body BD, and two drive wheels 12R and 12L (refer to FIG. 2) provided at the bottom of the body BD, which are individually driven to enable the body BD to move forward/backward and turn. At the center of the body BD, an infrared CCD sensor 73 is provided as the camera. This infrared CCD sensor 73 is movably mounted and therefore it is possible to take images of the front side of the body BD. As will be described below with reference to FIGS. 4 and 5, it is also possible to take images of the inside of a dust box 90 (not shown) disposed within the body BD.

Moreover, seven ultrasonic sensors 31 (31a to 31g) are disposed as distance meters, below the infrared CCD sensor 73. Each of the ultrasonic sensors 31 comprises a transmitter that generates ultrasonic wave and a receiver that receives the ultrasonic wave transmitted from the transmitter and reflected from a wall in front thereof, and it is possible to calculate the distance to the wall, from the time during which an ultrasonic wave is transmitted from the transmitter and received by the receiver. Of these seven ultrasonic sensors 31, a ultrasonic sensor 31d is disposed at the center front of the body BD, and each pair of ultrasonic sensors 31a and 31g, 31b and 31f, and 31c and 31e is disposed symmetrically at the left and right sides of the body BD. When the body BD is traveling perpendicular to the front wall, the distances calculated by a symmetrically disposed pair of ultrasonic sensors are equal.

Also, at the right and left sides of the front of the body BD, pyroelectric sensors 35 (35a and 35b) are provided respectively as human sensors. The pyroelectric sensors 35a and 35b can detect a human located in the vicinity of the body BD by detecting infrared rays emitted from the human body. Also, pyroelectric sensors 35c and 35d, not shown in FIG. 1, are disposed at both sides of the rear of the body BD respectively. This realizes detection range of 360 degrees around the body BD.

In FIG. 2, two drive wheels 12R and 12L are provided at the right and left edges of the bottom of the body BD. Also, at the front (in the traveling direction) of the bottom of the body BD, three auxiliary wheels 13 are disposed. In addition, at the upper right, lower right, upper left, and lower left of the bottom of the body BD, step sensors 14 are provided respectively that detects a step or irregularity of the floor surface. A main brush 15 is mounted lower than the center of the bottom of the body BD. The main brush 15 is rotated by a main brush motor 52 (not shown) to sweep the floor clear of dust. The opening adjacent to the main brush 15 is a suction hole through which the dust collected by the brush is sucked in. A side brush 16 is provided at the upper right and upper left of the bottom of the body BD respectively.

The self-propelled cleaner 10 of the present invention is equipped with various other sensors in addition to the ultrasonic sensors 31, pyroelectric sensors 35, and step sensors 14 shown in FIGS. 1 and 2. These other sensors are described below with reference to FIG. 3.

FIG. 3 is a block diagram illustrating the configuration of the self-propelled cleaner shown in FIGS. 1 and 2. In this figure, a CPU 21, a ROM 23, and a RAM 22 are connected to the body BD through a bus 24. The CPU 21 performs various controls according to control programs and various parameter tables stored in the ROM 23, using the RAM 22 as a work area.

The body BD contains a battery 27 and the CPU 21 can monitor the remaining capacity of the battery via a battery monitoring circuit 26. Also, the battery 27 has a charging terminal 27a for charging from a charging device 100 described below. The battery 27 is charged by connecting an electrical supply terminal 101 of the charging device 100 to the charging terminal 27a. The battery monitoring circuit 26 detects the remaining capacity mainly by monitoring the voltage of the battery 27. Moreover, the body BD has a voice synthesis circuit 29a connected to the bus 24, and a speaker 29b makes a voice sound according to a voice signal generated by the voice synthesis circuit 29a.

Furthermore, the body BD is equipped with the ultrasonic sensors 31 (31a to 31g) as distance meters, the pyroelectric sensors 35 (35a to 35d) as human sensors, and the step sensors 14 (refer to FIGS. 1 and 2). In addition to these sensors, the body BD has a sidewall sensors 36R and 36L (not shown in FIGS. 1 and 2) to detect sidewalls. For the sidewall sensors 36R and 36L, for example, passive sensors or ultrasonic sensors may be employed. The body BD also has a gyro sensor 37. The gyro sensor 37 includes an angular velocity sensor to detect an angular velocity change caused by the traveling direction change of the body BD, and it is possible to detect the direction angle at which the body BD faces, by accumulating the output values of the angular velocity sensor 37a.

The self-propelled cleaner 10 of the present invention has the drive mechanism including; motor drivers 41R and 41L; drive wheel motors 42R and 42L; and a gear unit (not shown) intercalated between the drive wheel motors 42R and 42L and the drive wheels 12R and 12L. The motor drivers 41R and 41L finely control the rotation direction and rotation angle of the drive wheel motors 42R and 42L, when the self-propelled cleaner turns. Each of the motor drivers 41R and 41L outputs a drive signal corresponding to the instruction from the CPU 21. The gear unit and the drive wheels 12R and 12L may be implemented in various forms, such as circular rubber tires or endless belts.

Furthermore, the actual rotation direction and rotation angle of the drive wheels can be detected from the output of a rotary encoder (not shown) attached integrally with the drive wheel motors 42R and 42L. Also, instead of directly coupling the rotary encoder to the drive wheels, a freely rotating driven wheel may be provided near each of the drive wheels, and the amount of rotation of the driven wheels may be fed back so that the actual amount of rotation can be detected even when the drive wheels are skidding. An acceleration sensor 44 detects the accelerations in the XYZ axial directions, and outputs the detection results. The gear unit and the drive wheels 12R and 12L may be implemented in various forms, such as circular rubber tires or endless belts.

The cleaning mechanism of the self-propelled cleaner 10 of the present invention comprises: two side brushes 16 (refer to FIG. 2) disposed at the bottom of the body BD; a main brush 15 (refer to FIG. 12) disposed at the center of the bottom of the body BD; and a suction fan (not shown) that sucks the dust collected by the main brush 15 into the dust box 90 to store therein. The main brush 15 is driven by a main brush motor 52 and the suction fan is driven by a suction motor 55. To the main brush motor 52 and suction motor 55, driving power is supplied from motor drivers 54 and 56 respectively. The cleaning by means of the main brush 15 is controlled by the CPU 21 according to the floor condition, battery capacity, instruction from the user, and the like.

The body BD contains a wireless LAN module 61, and the CPU 21 can communicate with an external LAN according to the prescribed protocol. The wireless LAN module 61 assumes the existence of an access point (not shown), and the access point can connect to an external wide area network (for example, the Internet) via routers or the like. This makes it possible to send/receive ordinary E mails via the Internet and to browse Web sites. The wireless LAN module 61 comprises a standardized card slot, a standardized wireless LAN card connected to the card slot, and the like. Of course, the card slot can accommodate other standardized cards.

Also, the body BD is provided with the infrared CCD sensor 73 and an infrared ray source 72. The imaging signal generated by the infrared CCD sensor 73 is transmitted to the CPU 21 through the bus 24, and is processed by the CPU 21. The infrared CCD sensor 73 has an optical system capable of taking images of the front side of the body BD, and produces an electric signal according to an infrared ray input from the field of view realized by the optical system. Specifically, the infrared CCD sensor has a large number of photodiodes, each of which are arranged corresponding to each pixel at the image forming position of the optical system, and each photodiode generates an electric signal corresponding to the electric energy of an input infrared ray. Then, the generated imaging signal is output to the CPU 21 accordingly.

Although this embodiment is configured using a camera that takes advantage of changes in the infrared rays entering the infrared CCD sensor 73, other configurations are possible. For example, it is possible to take images in color if the processing capacity of the CPU 21 increases, a flesh-colored area which is characteristic of a human body is located, and an intruder based on the size and change of the area is detected. Of course, a CMOS may be employed instead of the CCD. Furthermore, if an extremely high processing capacity is required from the CPU 21, an image processor dedicated to the image processing for imaging signals may be added, or a VRAM may be provided in addition to the RAM 22. Since the imaging signals can be input to the bus 24 within the body BD, the image processor, the VRAM, or the like should be provided in the body BD and be connected to the bus 24.

Now, the operation of the self-propelled cleaner 10 of the present invention is described.

The self-propelled cleaner 10 provides three modes: (A) automatic cleaning mode, (B) navigation mode, and (C) monitoring mode, from which the user can select a desired mode. A brief description of each of these three modes will follow.

(A) Automatic Cleaning Mode:

When set to the automatic cleaning mode, the self-propelled cleaner 10 performs cleaning while automatically traveling according to the control program stored in the ROM 23 or the like. If a wall or an uneven surface of the floor is detected by the sensors, a traveling control is performed based on the control program.

(B) Navigation Mode:

When set to the navigation mode, the self-propelled cleaner 10 moves close to the position at which the infrared beam emitted from a remote control hits, and cleans the area around there. That is, in the navigation mode, the self-propelled cleaner 10 does not perform cleaning while automatically traveling, as in the automatic cleaning mode, but the user instructs the area to be cleaned with the remote control and navigates the self-propelled cleaner to that area to clean there.

(C) Monitoring Mode:

When set to the monitoring mode, the self-propelled cleaner 10 monitors for an intruder. Specifically, the pyroelectric sensors 35 and the infrared CCD sensor 73 are used to monitor, and if an intruder is detected, an alarm signal is transmitted to the user located outside the room. This monitoring mode will be described in detail with reference to FIGS. 5 to 7.

The flow of the main process executed by the self-propelled cleaner 10 shown in FIGS. 1 to 3 is described with reference to the flowchart shown in FIG. 4. First, the initialization is made at step S100. At this step, the registers in the CPU 21, the RAM 22, and the like are cleared for initialization.

Then, at step S110, it is determined whether or not a mode selection instruction is issued. This step determines if an instruction to select one of the three modes i.e. automatic cleaning mode, navigation mode, and monitoring mode, is input. If it is determined at step S110 that the automatic cleaning mode is selected, then the automatic cleaning mode performing process is performed at step S120. If it is determined at step S110 that the navigation mode is selected, then the navigation mode performing process is performed at step S130. Likewise, if it is determined at step S110 that the monitoring mode is selected, then the monitoring mode performing process is performed at step S140. This monitoring mode performing process will be described below with reference to FIG. 5.

In the case wherein Step S120, S130, or S140 is performed, or, it is determined at step S110 that there is no mode selection instruction, it is determined whether an instruction to power off the self-propelled cleaner 10 is input or not. If the instruction to power off the self-propelled cleaner 10 is not input, then control returns to step S110. If the instruction is input, the main process is terminated.

Now, the monitoring mode performing process is described that is invoked and executed at step S140 of the flowchart shown in FIG. 4. FIG. 5 is a flowchart illustrating the flow of the monitoring mode performing process, and FIGS. 6 and 7 are schematic diagrams showing the operation of the self-propelled cleaner 10 when the steps of the flowchart in FIG. 5 are being performed.

When the monitoring mode performing process is started, the pyroelectric sensors 35 (35a to 35d) are enabled at step S500. When all the pyroelectric sensors 35 are enabled, it is possible to detect infrared rays emitted by a human body and thereby detect an intruder in the vicinity of the body BD. Next, at step S510, it is determined whether an intruder is detected or not by the pyroelectric sensors 31. If it is determined that an intruder is detected, an alarm mail is transmitted at step S520. Specifically, an alarm mail to the effect that an intruder was detected is sent to the user's cell phone or the like over the Internet or any other network.

After step S520 is performed, an alarm sound is made at step S530. Specifically, the CPU 21 sends a prescribed signal to the voice synthesis circuit 29a, the voice synthesis circuit 29a generates a voice signal based on the sent signal, and outputs an alarm sound from the speaker 29b. This alarm sound informs the user of the presence of an intruder if the user is located nearby, and also serves as a warning to the intruder.

Step S530 is performed, or, if it is determined that an intruder is not detected at step S510, it is determined at step S540 whether a predetermined period of time (for example, one minute) has passed or not. If it is determined that the predetermined period of time has not yet passed, control returns to step S510. If it is determined that the predetermined period of time has passed, all the pyroelectric sensors 35 are disabled at step S550. That is, all the pyroelectric sensors 35 are disabled to detect infrared rays from a human body.

After step S550 is performed, the body BD is turned at a predetermined angle (for example, 30 degrees). At this step, by driving only one of the drive wheel motors 42R and 42L, the body BD is turned only the predetermined angle and then is stopped. Next, at step S570, images are taken with the infrared CCD sensor 73 with the body BD at rest. After step S570 is performed, it is determined whether an intruder is imaged or not with the infrared CCD sensor 73. Specifically, this step can be done by detecting the difference between the frames (a frame of video signal) of video signals based on the imaging signals from the infrared CCD sensor 73. That is, if there is a difference between two images taken at different times, it is determined that an intruder is present. If it is determined that an intruder is imaged, steps S520 and S530 are performed.

In the case wherein step S530 is performed, or, it is determined that no intruder is imaged, it is determined whether the body BD has turned around. This determination can be made, for example, based on the direction angle of the body BD detected by the gyro sensor 37. If it is determined that the body BD has not turned around, control is returned to step S560. By performing steps S560, S570, and S590 repeatedly, images are taken with the infrared CCD sensor 73 while the body BD is being rotated at predetermined degrees at a time.

If it is determined at step S590 that the body BD has turned around, it is determined at step S600 whether there is an instruction to release the monitoring mode or not. If it is determined that there is no release instruction, control is returned to step S500. If it is determined that there is a release instruction, the monitoring mode performing process is terminated.

A concrete example of performing the steps of the flowchart in FIG. 5 is described with reference to FIGS. 6 and 7. First, when each of the pyroelectric sensors 35 (35a to 35d) is enabled (step S500), it is possible to detect infrared rays from a human body, thus allowing the detection of an intruder located near the body BD. The colored portions in FIG. 6 indicate the detectable range of the pyroelectric sensors 35. If an intruder is detected while the pyroelectric sensors are enabled, an alarm mail is transmitted to the user's cell phone or the like (step S520), and also an alarm sound is output from the speaker 29b (step S530).

When a predetermined period of time (for example, one minute) has passed after the pyroelectric sensors 35 are enabled, the pyroelectric sensors 35 are disabled (step S550), and then images are taken with the infrared CCD sensor 73 each time the body BD stops, while being rotated at predetermined angles at a time (steps S560 and S570). The colored portion in FIG. 7 indicates the detectable range of the infrared CCD sensor 73. The outline arrow in FIG. 7 indicates the rotation direction of the body BD. By having the infrared CCD sensor 73 take images while the body BD is turned around, an intruder can be detected in a wider range than when the pyroelectric sensors shown in FIG. 6 are used. If an intruder is detected based on the result of analyzing the imaging signals from the infrared CCD sensor 73, an alarm mail is sent to the user's cell phone or the like (step S520), and also an alarm sound is output from the speaker 29b (step S530). Thus, with the self-propelled cleaner 10 of the present invention, since the infrared CCD sensor takes images at predetermined time intervals (one minute), power consumption can be substantially reduced compared with when the infrared CCD sensor takes images all the time.

(4) Modifications:

In the above embodiment, a case is described where the infrared CCD sensor 73 takes images at predetermined time intervals (one minute) while the body BD is turning, in the monitoring mode. In the present invention, the timing at which the turning of the body BD and the image taking with the camera is started is not limited. For example, it is possible to extract a random number at certain time intervals (such as 3 seconds), and start the turning of the body BD and image taking with the camera when an extracted random number matches the predetermined value. In this embodiment, turning of the body BD and image taking with the camera are performed at random time intervals.

As described above, the self-propelled cleaner 10 according to the embodiments normally detects an intruder with pyroelectric sensors 35 which consume less power, and each time a predetermined period of time has passed, detects an intruder with the infrared CCD sensor 73 while turning the body BD. This can reduce the time of operation during which the infrared CCD sensor 73 consuming more power is used, thus making it possible to reduce power consumption. Moreover, since the self-propelled cleaner is designed to cause the drive mechanism provided therein to turn the body BD, it is not necessary to additionally provide a device to turn the infrared CCD sensor 73, thus reducing the manufacturing cost.

Claims

1. A self-propelled cleaner including a body equipped with a cleaning mechanism, a drive mechanism to steer and drive said body, a plurality of human sensors that detect infrared rays emitted by a human body, and an infrared camera, wherein: said human sensor is caused to detect said infrared rays from a human body, with the image taking by said infrared camera disabled; an intruder detection processor is provided that causes said infrared camera to take images while turning said body by controlling said drive mechanism, when the predetermined time has passed or when the value of a random number extracted at certain time intervals matches the predetermined value; and the detection of infrared rays by said human sensors is disabled while said intruder detection processor causes said infrared camera to take images.

2. A self-propelled cleaner including a body equipped with a cleaning mechanism, a drive mechanism to steer and drive said body, a plurality of human sensors that detect infrared rays emitted by a human body, and a camera, wherein: an intruder detection processor that causes said human sensors to detect said infrared rays from said human body, with the image taking by said camera disabled, and each time predetermined conditions are satisfied, controls said drive mechanism to turn said body and simultaneously causes said camera to take images.

3. The self-propelled cleaner according to claim 2, wherein said intruder detection processor controls said drive mechanism to turn said body and simultaneously causes said camera to take images, each time the predetermined time period has passed.

4. The self-propelled cleaner according to claim 2, wherein said intruder detection processor controls said drive mechanism to turn said body and simultaneously causes said camera to take images, each time the value of a random number extracted at certain time intervals matches the predetermined value.

5. The self-propelled cleaner according to claim 2, wherein the detection of infrared rays by said human sensors is disabled while said intruder detection processor causes said camera to take images.

6. The self-propelled cleaner according to claim 2, wherein said camera is an infrared camera.

7. The self-propelled cleaner according to claim 2, wherein said human sensors are disposed at the right and left sides of the front of said body, and are pyroelectric sensors that detect a human in the vicinity of said body by detecting infrared rays emitted by the human body.

8. The self-propelled cleaner according to claim 2, wherein said drive mechanism comprises two drive wheels disposed at the center right and left edges of the bottom of said body, and three auxiliary wheels provided at the front of the bottom of said body.

9. The self-propelled cleaner according to claim 8, wherein said drive mechanism comprises drive wheel motors to drive said drive wheels, and a rotary encoder that is integrally attached to said drive wheel motors, and the actual rotation direction and rotation angle of said drive wheel is detected from the output of said rotary encoder.

10. The self-propelled cleaner according to claim 6, wherein said infrared camera comprises an infrared CCD sensor and an infrared ray source.

11. The self-propelled cleaner according to claim 10, wherein said infrared CCD sensor has an optical system capable of taking images of the front side of said body, and an electric signal is generated that corresponds to an infrared ray input from the field of view realized by said optical system.

12. The self-propelled cleaner according to claim 2, wherein said intruder detection processor locates flesh-colored areas that are characteristic of a human body, based on the color images taken, and detects an intruder based on the size and changes of said areas.

13. The self-propelled cleaner according to claim 8, wherein said intruder detection processor turns said body at predetermined angles by driving only one of said left and right drive wheels, and then stops said body.

14. The self-propelled cleaner according to claim 2, wherein said intruder detection processor determines whether or not an intruder is imaged based on the difference between two images of the same area taken at different times, by detecting the difference between frames of video signals based on imaging signals from said camera.

15. The self-propelled cleaner according to claim 2, wherein said intruder detection processor has a gyro sensor and determines whether or not said body has turned around, based on the direction angle of said body detected by said gyro sensor.