JP7033821B2 - Cleaning device with debris sensor - Google Patents

Description

Cross-reference to related patent documents This patent application shall be incorporated herein by reference, as all the contents of the following commonly owned US patent applications or patents have been described.

It is US Patent Application No. 09 / 768,773 filed on January 24, 2001, and is currently US Patent No. 6,594,844, titled "Robot Obstacle Detection System (Atty.Dkt). .DP-4) "
US Provisional Patent Application No. 60 / 345,764 filed on January 3, 2002, title "Cleaning Mechanisms for Autonomous Robot"
US Patent Application No. 10 / 056,804, filed January 24, 2002, entitled "Methods and Systems for Robot Localization and Confinement (Atty Dkt. DP." DP-6) "
US Pat. an Autonomous Robot (Atty Dkt. DP-5) "
US Patent Application No. 10 / 320,729 filed on December 16, 2002, title "Autonomous Floor-Cleaning Robot (Atty Dkt. DP-10)"
US Patent Application No. 10 / 661,835 filed on September 12, 2003, title "Navigation Control System for Robotic Device (Atty Dkt. DP-9)"
INDUSTRIAL APPLICABILITY The present invention relates to a cleaning device in general, and particularly to a debris sensor for detecting a momentary collision due to debris in the cleaning path of the cleaning device and for enabling control of an operation mode of the cleaning device. The term "debris" is used herein to collectively refer to debris, dust, and / or other particles or objects collected by a vacuum cleaner or other cleaning device, whether autonomous or non-autonomous. Used for.

Background of the Invention Debris sensors, including some suitable for cleaning devices, are known in the art. Whether debris sensors are beneficial in autonomous cleaning devices, as disclosed in patent applications above, and also in non-autonomous cleaning devices, and are entering a particularly dirty area for the user. In response to debris detection, increase the power setting or allow some other behavioral settings to be modified.

An example of a debris sensor is disclosed below.

De Brey 3,674,316
De Brey 3,989,311
De Brey 4,175,892
Kurz 4,601,082
Westergreen 4,733,430
Martin 4,733,431
Harkonen 4,829,626
Takashima 5,105,502
Takashima 5,136,750
Kawakami 5,163,202
Yang 5,319,827
Kim 5,440,216
Gordon 5,608,944
Imamura 5,815,884
Imamura 6,023,814
Kasper 6,446,302
Gordon 6,571,422
Of the examples disclosed herein, many such debris sensors are optical in nature and use light emitters and detectors. For example, in a typical design used for a vacuum cleaner, the optical transmitter and receiver of the optical sensor are arranged so as to be exposed to a suction path or a cleaning path through which dust flows. Therefore, during the use of the vacuum cleaner, the dust particles are likely to emit light and adhere to the exposed surface of the detected optical transmitter and optical receiver, degrading the performance of the optical sensor.

Therefore, it is desired to provide a debris sensor that does not deteriorate due to the adhesion of debris.

Further, the debris sensor typical of the prior art is sensitive to the level of debris deposited in the pool or clean path, but not particularly sensitive to momentary debris collisions or encounters.

Therefore, it can instantly sense and respond to debris collisions, respond immediately to debris on the floor or other surface to be cleaned, and respond to atmospheric flow fluctuations, momentary power, or other operating conditions of the cleaning device. It is desirable to provide a debris sensor with reduced sensitivity.

Autonomous cleaning with behavioral modes, movement patterns, or behaviors that respond to detected debris, such as maneuvering the device towards a "dirty" area, for example, based on a signal generated by a debris sensor. It is also beneficial to provide the device.

Further, it is desirable to provide a debris sensor that can be used to control, select, or change the operating mode of either autonomous or non-autonomous cleaning equipment.

The present invention provides a debris sensor and a device utilizing such a debris sensor, wherein the sensor responds instantaneously to a collision of debris and the operating mode of an autonomous or non-autonomous cleaning device including such a sensor. Can be used to control, select, or change.

One aspect of the present invention is an autonomous cleaning device, which is a drive system that can operate so as to enable movement of the cleaning device, and a controller that is in communication with the drive system to control the drive system. A controller including a processor capable of operating to provide at least one movement pattern of the cleaning device, a brush assembly capable of sweeping debris toward the cleaning path of the cleaning device, and the cleaning device debris. The processor comprises a debris sensor that produces a debris signal indicating that it has encountered a debris signal, and the processor selects one of the predetermined operating modes of the cleaning device in response to the debris signal.

The selection of the operating mode can include selecting the movement pattern of the cleaning device.

The movement pattern can include spot coverage of the area containing debris, or maneuvering the cleaning device towards the area containing debris. The debris sensor can include first and second debris sensing elements that are evenly spaced apart and can operate to generate first and second debris signals, respectively, and the processor can include the first and second debris signals. In response to each of the above, it is possible to select a movement pattern that steers toward the side with more debris (for example, left or right).

The debris sensor is located close to the cleaning path of the cleaning device at the location where the debris swept up by the brush assembly collides, and in response to the debris collision, it produces a signal indicating that it has collided with the debris. Sensor elements can be included.

The debris sensor of the present invention can also be incorporated into a non-autonomous cleaning device. The present aspect of the present invention comprises a piezoelectric sensor element located close to a clean path and generating a debris signal indicating that it has collided with debris in response to a collision with debris, and a piezoelectric sensor element in response to the debris signal. It can include a processor that changes the operating mode of the debris. To change the operating mode, turn on a user-recognizable indicator light, change the power setting (for example, higher power setting when more debris is encountered), or reduce the speed of movement of the device. Can be included.

A further aspect of the invention is a debris sensor, located near or within the debris path of the debris device, that produces a first signal indicating that it has collided with debris in response to a collision with debris. It includes a piezoelectric element that can be operated to process a first signal to generate a second signal that is characteristic of the debris encountered by the purifier. The feature may be, for example, a debris amount or volume parameter, or a vector from the current position of the cleaning device to the area containing the debris.

Another aspect of the invention utilizes the motion of an autonomous cleaning device covering the floor or other surface to process the debris signal and calculate the debris gradient in conjunction with knowledge of the cleaning device movement. The debris gradient indicates the change in the debris collision count as the autonomous cleaning device moves along the surface. By examining the sign of the gradient (positive or negative in relation to the increase or decrease of debris), the autonomous cleaning device controller continuously adjusts the path or movement pattern of the device to effectively capture the debris area. Clean.

These and other aspects, features, and advantages of the invention will be more apparent from the following description with reference to the accompanying drawings in which embodiments of the invention are illustrated and described.

It is a top view of the typical autonomous cleaning device as an example which can adopt the debris sensor of this invention. FIG. 1 is a block diagram of a typical hardware element of the robotic apparatus of FIG. 1 and includes the debris sensor subsystem of the present invention. FIG. 1 is a side view of the robot device of FIG. 1, showing a debris sensor according to the present invention, which is located in a clean or vacuum path where debris swept up by the main clean brush element collide. It is an exploded view of the piezoelectric debris sensor according to this invention. It is a schematic diagram of the debris sensor signal processing architecture which concerns on this invention. It is a schematic diagram of the signal processing circuit for the debris sensor architecture of FIG. It is a schematic diagram of the signal processing circuit for the debris sensor architecture of FIG. It is a schematic diagram of the signal processing circuit for the debris sensor architecture of FIG. It is a schematic diagram which shows the debris sensor in a non-autonomous cleaning device. It is a flowchart of the method which concerns on one Embodiment of this invention.

A more complete understanding of the invention, and associated features and benefits, will be obtained by reference to the following detailed description of the invention for consideration in carrying with the accompanying figures.
Detailed Description of the Invention The debris sensor of the present invention can be incorporated into a wide range of autonomous cleaning devices (and, in fact, also in the non-autonomous cleaning device shown as an example in FIG. 7). It will be described by the flow of the typical autonomous cleaning device shown in 3. Further details on the structure, function, and mode of action of such autonomous purifiers are described in the patent applications cited in the cross-reference section above, each of which is incorporated herein by reference. do. Therefore, the detailed description below is composed of the following sections.

I. Typical autonomous cleaning device
II. Behavior mode of autonomous cleaning device
III. Debris sensor structure
IV. Signal processing V. Conclusion I. Autonomous Cleaning Device Throughout some figures, similar reference numbers refer to the figure identifying the corresponding or similar element, FIG. 1 is a schematic plan view of a typical autonomous cleaning robot device 100. Yes, a debris sensor according to the present invention is incorporated in the device. FIG. 2 is a block diagram of the hardware of the robot device 100 of FIG.

The robot device 100 commercialized by iRobot Corporation of Burlington, MA under the registered trademark of ROOMBA, hardware and behavior mode (coverage behavior or movement pattern for clean movement; evacuation behavior to temporary movement pattern; And examples of safe behaviour in emergencies) are provided below for a more complete understanding of how the debris sensing system of the present invention is employed. However, the present invention can also be applied to non-autonomous cleaning devices, examples of which are described below in association with FIG.

In the description below, the terms "forward" and "front" are used to indicate the main direction (forward) of movement of the robotic device (see the arrow indicated by the reference letter "FM" in FIG. 1). The front / rear axis FA _x of the robot device 100 coincides with the center diameter of the robot device 100, which divides the robot device 100 into approximately symmetrical right and left halves, which are defined as the main side and the non-main side, respectively. ..

An example of such a robotic apparatus 100 has a substantially disk-shaped storage structure that includes a chassis 102 and an external shell 104 secured to the chassis 102 to define a minimum height structural envelope. (To facilitate movement under the furniture). Hardware with the robotic apparatus 100 is generally a power system, a start-up power system (also referred to here as a "drive system"), a sensor system, a control module, a side brush assembly, or a self-adjusting cleaning head system, respectively. It can be classified as a basic element, all of which are integrated in combination with the storage structure. In addition to such classified hardware, the robotic appliance 100 further includes a front bumper 106 with a schematic arc configuration and a front wheel assembly 108.

The front bumper 106 (shown as a single component; or a two-part component) is movably integrated with the chassis 102 (by a pair of displaceable support members) and extends outward from it. ing. Whenever the robotic apparatus 100 collides with an obstacle (eg, a wall, furniture) during its movement, the bumper 106 is displaced (compressed) towards the chassis 102 and stretched back when contact with the obstacle ends. Return to the (working) posture.

The front wheel assembly 108 is mounted on the chassis 102 in a biased combination so that the front wheel assembly 108 is in a retracted position during the cleaning operation (due to the weight of the robotic apparatus 100) and is being cleaned. Freely rotate on the surface. When the front wheel assembly 108 encounters a steep slope (eg, downstairs, mezzanine floor) during operation, the front wheel assembly 108 is tilted into an extended position.

The hardware of the power system, which supplies energy to power the electrically operated hardware of the robotic apparatus 100, comprises a rechargeable battery pack 110 (and associated leads) integrated in combination with the chassis 102.

As shown in FIG. 1, the activation power system provides means for propelling the robotic appliance 100 while the robotic appliance 100 is in motion and operating a cleaning mechanism such as a side brush assembly and a self-adjusting cleaning head. The start-up power system has left and right main drive wheel assemblies 112L and 112R, their associated independent motors 114L and 114R, and electric motors 116 and 118 for each to operate the side brush assembly and self-adjusting clean head. I have.

The electric motors 114L and 114R are mechanically coupled to the main drive wheel assemblies 112L and 112R, respectively, and are shown on the left and in FIG. 1 as a response to the execution of the mode of action or as detailed below. It is operated independently by the control signal generated by the control module in response to the debris signal generated by the right debris sensors 125L and 125R.

Due to the independent operation of the electric motors 114L and 114R, the main drive wheel assemblies 112L and 112R are (1) rotated in the same direction and at the same speed to propel the robot device 100 forward or backward in a straight line. (2) The robot device 100 is rotated differentially (one wheel assembly is not rotated) in order to realize various right and / or left rotation patterns (from sharp rotation to shallow rotation). (Including), and (3) rotating the robot device 100 in its place, i.e., rotated at the same speed in opposite directions for "rotation on a 10 cent silver coin", of the movement function of the robot device 100. Offers a wide repertoire.

As shown in FIG. 1, the sensor system comprises a variety of different sensor units that operate to generate signals that control the behavioral mode operation of the robotic device 100. The robot device 100 described above includes an obstacle detection unit 120, a cliff detection unit 122, a wheel drop sensor 124, an obstacle tracking unit 126, a virtual wall omnidirectional detector 128, a stall sensor unit 130, a main wheel encoder unit 132, and Includes left and right debris sensors 125L and 125R according to the invention, which are described in detail below.

In an exemplary embodiment, the obstacle (“collision”) detection unit 120 may be an IR break beam sensor mounted in combination with a displaceable support member pair of front bumper 106. These obstacle detection units 120 indicate one or more relative displacements between one or more pairs of support members whenever the robotic apparatus 100 collides with an obstacle such that the front bumper 106 is compressed. It operates to generate two or more signals. These signals are processed by the control module to determine the approximation point (and the mode of action to be performed) in contact with the injury with respect to the front-rear axis _FAX of the robotic appliance 100.

The cliff detection unit 122 is mounted in combination with the front bumper 106. Each cliff detection unit 122 is an IR emitter / detector that operates and is configured to establish a focus so that radiation emitted downward from the emitter is reflected from the surface being detected across the detector. Have a pair. If the reflected radiation is not detected by the detector, i.e., when a steep slope is encountered, the cliff detection unit 122 signals the control module (which causes one or more modes of action).

A wheel drop sensor 124, such as a contact switch, is integrated in combination with each of the main drive wheel assemblies 112L and 112R and the front wheel assembly 108, when any of the wheel assemblies are in a pulled out position, i.e., across. Whenever it is not in contact with a surface, it operates to generate a signal (which causes the control module to perform one or more modes of action).

The obstacle tracking unit 126 in the above embodiment is an IR emitter / detector pair mounted on the "main" side (right side of FIG. 1) of the robotic apparatus 100. The emitter / detector pair is similar in configuration to the cliff detection unit 122, but is arranged so that the emitter can emit lateral radiation from the main side of the robotic device 100. Unit 126 operates to send a signal to the control module whenever an obstacle is detected as a result of the radiation reflected from the obstacle and detected by the detector. The control module causes one or more modes of action to be executed in response to this signal.

The virtual wall detection system used with the above-described embodiment of the robotic apparatus 100 is a stand-alone type that transmits an omnidirectional detector 128 mounted on the top of an external shell 104 and an axially directed confinement beam. It is equipped with a transmission unit (not shown). In the stand-alone transmission unit, the emitted confinement beam obstructs the access path to the defined work area, thereby cleaning the robot device 100 and the defined work area (for example, the robot device 100). It is limited to the operation of the entrance that is confined in the room). Upon detecting the confinement beam, the omnidirectional detector 128 sends a signal to the control module (so that one or more modes of action are performed and the robotic device 100 is generated by the stand-alone transmit unit. Move away from the confined beam).

The stall sensor unit 130 is integrated in combination with the respective motors 114L, 114R, 116, and 118, and when a change in current is detected in the associated motor (which indicates a fault condition in the corresponding driven hardware). ), Operates to send a signal to the control module. The control module operates to perform one or more modes of action in response to such signals.

The main wheel encoder unit 132 (see FIG. 2) is integrated in combination with each main drive wheel assembly 112L and 112R and operates to detect the corresponding wheel rotation and send a corresponding signal to the control module. (Wheel rotation can be used to estimate the distance traveled by the robot device 100).

Control Module With reference to FIG. 2, the control module includes a sensor of the robotic apparatus 100, a microprocessing unit 135 including an I / O port connected to controllable hardware, and a microcontroller (Motorola MC9512E128CPV 16-bit controller). Like), and with ROM and RAM memory. The I / O port acts as an interface between the microcontroller and the sensor unit (including the left and right debris sensors 125 described in more detail below) and the controllable hardware, and the signal generated by the sensor unit is the microcontroller. And transfers the control (instruction) signal generated by the microcontroller to controllable hardware to execute a special mode of action.

The microcontroller processes sensor signals, executes a special mode of action based on such processed signals, and controls controllable hardware based on the mode of action performed on the robotic apparatus 100. (Instruction) Operates to execute an instruction set for generating a signal. The clean coverage and control program for the robotic appliance 100 is stored in the ROM of the microprocessing unit 135, in which behavioral mode, sensor processing algorithm, control signal generation algorithm, and which behavioral mode or control of the robotic appliance 100 is controlled. It contains a priority algorithm that determines whether to give to multiple modes of action. The RAM of the microprocessing unit 135 is used to store the activity state of the robot device 100, and the ID of the action mode (multiple action modes) in which the robot device 100 is currently operated and the hardware command related thereto are stored. include.

Referring again to FIG. 1, a side brush assembly 140 configured and operating to collect external particles around the containment structure and direct the particles towards a self-adjusting cleaning head system is shown. The side brush assembly 140 provides the robot device 100 with the ability to clean the surface close to the bottom plate when the robot device 100 is operating in the "obstacle tracking" behavior mode. As shown in FIG. 1, preferably, the side brush assembly 140 is mounted in combination with the chassis 102 in the front quadrant on the main side of the robotic apparatus 100.

The self-adjusting cleaning head system 145 for the robotic apparatus 100 described above comprises a two-stage brush assembly and a vacuum assembly, each of which is independently powered by an electric motor (reference number 118 in FIG. 1 is in fact). Identifies two independent electric motors, one for the brush assembly and one for the vacuum assembly). The cleaning function of the robot device 100 is commonly characterized by the width of the cleaning head system 145 (see reference letter W in FIG. 1).

Now with reference to FIG. 3, in one embodiment of the robotic apparatus 100, the cleaning brush assembly comprises an asymmetric, anti-rotating flapper and main brush elements 92 and 94, respectively, which are in front of the vacuum assembly inlet 84. And operates to direct the particulate debris 127 towards the removal dust cartridge 86. As shown in FIG. 3, the robotic apparatus 100 can also include left and right debris sensor elements 125PS, which may be piezoelectric sensor elements, as described in detail below. The piezoelectric debris sensor element 125PS can be located in the cleaning path of the robotic appliance 100, for example, mounted on the roof of the cleaning head, whereby the particles 127 swept up by the brush element and / or attracted by vacuum. In the event of a collision, the debris sensor element 125PS produces an electrical pulse indicating that the debris has collided and, in this way, the debris is present in the area where the autonomous cleaning device is operating.

More specifically, in the arrangement shown in FIG. 3, the sensor element 125PS is substantially located on the axis AX where the main and flapper brushes 94 and 92 meet along it, whereby the particles are at maximum force debris sensor element. Collide with 125PS.

As shown in FIG. 1 and as described in more detail below, the robotic cleaning device can be fitted with left and right piezoelectric debris sensors to signal such that the robotic device points towards a "dirty" area. Generates separate left and right debris signals that can be processed for sending.

The operation of the piezoelectric debris sensor, along with signal processing and selection of the behavioral mode based on the debris signal generated by the piezoelectric debris sensor, is discussed below according to a brief description of the general aspects of the behavioral mode of the purifier.
II Action Mode The robotic apparatus 100 can employ various action modes in order to effectively clean the defined work area, where the action mode is a layer of the control system and can operate in parallel. The microprocessing unit 135 executes a priority arbitration scheme to identify and execute one or more major modes of operation for any given scenario based on inputs from the sensor system. Works like this.

The action mode of the robot device 100 described above is characterized by (1) coverage action mode, (2) evacuation action mode, and (3) safe action mode. The coverage action mode is primarily designed to allow the robot device 100 to perform its cleaning operation in an efficient and effective manner, while the evacuation and safe action modes are signals from the sensor system to the robot. It is a priority action mode that is executed when the normal operation of the device 100 is likely to be hindered, for example by encountering an obstacle, or, for example, a steep slope is detected and is likely to be hindered.

Typical and exemplary coverage behavior (cleaning) modes of the robotic apparatus 100 include (1) "spot coverage" patterns, (2) "obstacle tracking (or" edge cleaning ") coverage" patterns, and (3). ) Includes "room coverage" pattern. The "spot coverage" pattern causes the robot device 100 to clean a limited area within the defined work area, for example, a high traffic area. In a preferred embodiment, the "spot coverage" pattern is performed by a spiral algorithm (although other types of self-blocking region algorithms, such as polygons, can also be used). The spiral algorithm that causes the robot device 100 to move in an outward spiral (suitable) or inward spiral is a control signal from the microprocessing unit 135 to the main wheel assemblies 112L and 112R. The radius of gyration / plurality of radii is changed as a function of time (thus increasing / decreasing the spiral movement pattern of the robot device 100).

The robotic apparatus 100 may, for example, one or two of the obstacle detection units 120 for a predetermined or random time, for a predetermined or random distance (eg, maximum spiral distance), and / or until a special event occurs. Until the above is activated (collectively, the transitional state), it operates in the "spot coverage" pattern. Once a transitional state occurs, the robotic apparatus 100 has a different mode of operation, eg, a "straight-line" behavior mode (in a preferred embodiment of the robotic apparatus 100, the "straight-line" behavior mode is a low priority and the robot A different action mode, such as a "bound" action mode combined with a "straight line" action mode) or a default action that propels the robot on an approximate straight line at a pre-set speed of about 0.306 m / s. Execute or transition to that mode.

If the transient state is the result of the robot device 100 encountering an obstacle, the robot device 100 can take another action instead of transitioning to a different action mode. The robot device 100 can temporarily execute a certain action mode to avoid or evacuate an obstacle and resume the operation (that is, continue the spiral movement in the same direction) by controlling the spiral algorithm. do). Alternatively, the robotic apparatus 100 can temporarily execute a certain action mode to avoid or evacuate an obstacle and resume operation in the opposite direction, that is, under the control of a spiral algorithm. Reflective spiral movement).

The "obstacle tracking coverage" pattern allows the robotic apparatus 100 to be around an obstacle (eg, furniture) around a defined work area, eg, a room partitioned by a wall, and / or within the defined work area. Clean the surroundings. Preferably, the robot device 100 of FIG. 1 uses the obstacle tracking unit 126 (see FIG. 1) to continuously maintain its posture with respect to obstacles such as walls and furniture, and the robot device 100. The movement of the robot allows it to move closer to the surroundings of the obstacle and at the same time clean the surroundings. Different embodiments of the obstacle tracking unit 126 can be used to perform an "obstacle tracking" behavior pattern.

In the first embodiment, the obstacle tracking unit 126 is operated to detect the presence or absence of an obstacle. In another embodiment, the obstacle tracking unit 126 is operated to detect an obstacle and maintain a predetermined distance between the obstacle and the robotic apparatus 100. In a first embodiment, the microprocessing unit 135 performs a small clockwise or counterclockwise rotation in response to a signal from the obstacle tracking unit 126 to maintain its attitude towards the obstacle. It works like that. The robotic appliance 100 performs a small clockwise turn when the robotic appliance 100 transitions from obstacle detection to non-detection (from reflective to non-reflective), or the robotic appliance 100 performs from non-detection to detection (non-reflective). When transitioning from reflection to reflection), perform a small counterclockwise rotation. A similar rotational action is performed by the robotic appliance 100 to maintain a predetermined distance from the obstacle.

The robotic apparatus 100 may, for example, one or two of the obstacle detection units 120 for a predetermined or random time, for a predetermined or random distance (eg, maximum or minimum distance), and / or until a special event occurs. It is activated in the "obstacle tracking" action mode until one or more are activated a predetermined number of times (collectively, in a transitional state). In one embodiment, the microprocessing unit 135 is an obstacle detection unit in an "obstacle tracking" behavior mode that performs a minimum angle counterclockwise rotation to align the robotic device 100 with respect to an obstacle. When 120 is activated, the robot device is made to execute the "alignment" action mode.

The "room coverage" pattern can be used by the robotic apparatus 100 to clean any defined work area partitioned by walls, stairs, obstacles, or other barriers (eg, virtual wall units). A preferred embodiment of the "room coverage" pattern includes a "random bound" behavior mode combined with a "straight" behavior mode. Initially, the robotic apparatus 100 encounters an obstacle under the control of a "straight line" behavior mode, that is, a linear algorithm (main drive wheel assemblies 112L and 112R operating at the same rotational speed and in the same direction). Drive up to. When one or more obstacle detection units 120 are activated, the microprocessing unit 135 now calculates an acceptable range for the new direction based on the activated obstacle tracking units 126. Operate. The microprocessing unit 135 selects a new direction within an acceptable range and performs a clockwise or counterclockwise rotation to achieve the new direction with minimal movement. In certain embodiments, the new direction of rotation continues to move forward, increasing the cleaning performance of the robotic appliance 100. The new direction may be randomly selected from an acceptable directional range of directions or based on some statistical selection method, eg Gaussian distribution. In another embodiment of the "room coverage" behavior mode, the microprocessing unit 135 can be programmed to redirect randomly or a predetermined number of times without input from the sensor system.

The robotic apparatus 100 activates, for example, the obstacle detection unit 120 a predetermined number of times for a predetermined or random time, for a predetermined or random distance (eg, maximum or minimum distance), and / or until a special event occurs. It will operate in "room coverage" mode until it is done (collectively in a transitional state).

As an example, the robotic apparatus 100 can include four evacuation behavior modes: a "rotation" behavior mode, an "edge" behavior mode, a "wheel fall" behavior mode, and a "slow" behavior mode. Those familiar with this technique will recognize that other modes of action are available with the robotic apparatus 100. One or more of these modes of action are, for example, in one of the electric motors 116 and 118 of the side brush assembly 140 or the two-stage brush assembly, an increase in current above the low or high stall threshold, for a given time only. The front bumper 106 of the front bumper 106 is executed in response to the detection of the compressed posture and wheel fall.

In the "rotation" mode of action, the robotic apparatus 100 starts at a higher speed (eg, twice the nominal rotation speed) and decreases to a slower speed (half the nominal rotation speed) in random directions, i.e., respectively. Small panic rotations and large panic rotations rotate in place. Preferably, the small panic rotation is in the range of 45 ° to 90 ° and the large panic rotation is preferably in the range of 90 ° to 270 °. In the "rotation" action mode, the robot device 100 is stuck on an obstacle in the room, for example, on a high part of the carpet, on a sloping lamp stand, under the obstacle in the room. For example, avoid getting stuck under the sofa or being trapped in a small area.

In the "edge" action mode, a predetermined angle, eg, 60 °, or from the start of the "edge" action mode, without any of the injury detection units 120 being activated. Track the edge of the obstacle until it is rotated by an angle, eg 170 °. The "edge" behavior mode allows the robotic appliance 100 to pass through the smallest possible hole in order to evacuate from a small area.

In the "wheel drop" behavior mode, the microprocessing unit 135 temporarily reverses the directions of the main wheel drive assemblies 112L and 112R and then stops them. When the activated wheel drop sensor 124 is deactivated within a predetermined time, the microprocessing unit 135 re-executes the action mode that was being executed prior to the activation of the wheel drop sensor 124.

In response to an event, eg, activation of the wheel drop sensor 124 or cliff detection unit 122, a "slow" action mode is performed for a predetermined distance to slow down the robotic appliance 100 and then gradually return to its original operating speed. Return to.

When a safety condition is detected by the sensor subsystem, for example, a series of brush or wheel stalls that temporarily turn off the corresponding electric motor, or the wheel drop sensor 124 or cliff detection unit 122, When the robot device 100 is started after being increased by a predetermined time, the robot device 100 is generally turned off. In addition, an audible alarm is generated.

The above description of the action mode for the robot device 100 merely represents the type of action mode that can be performed by the robot device 100. Those familiar with this technique will recognize that the above behavioral modes can be performed in other combinations and / or situations, as well as other behavioral modes and movement patterns.
III Structure and operation of the debris sensor As shown in FIGS. 1 to 3, according to the present invention, the autonomous cleaning device (and similarly, the non-autonomous cleaning device shown as an example in FIG. 7) incorporates the debris sensor. It can be improved by this. In the embodiments illustrated in FIGS. 1 to 3, the debris sensor subsystem comprises left and right piezoelectric debris sensor elements 125L and 125R located near or within the cleaning path of the cleaning device and debris from the sensor. It comprises an electronic device element for processing a signal and transferring it to a microprocessing unit 135 or another controller.

When adopted in an autonomous robot cleaning device, the debris signal from the debris sensor selects the action mode (to be in spot cleaning mode), changes the operating state (such as speed, power, or other) and It can be steered in the direction of debris (especially equidistant left and right debris sensors are used to generate differential signals) or used to take other actions.

The debris sensor according to the present invention can also be incorporated into a non-autonomous cleaning device. For example, when adopted in a non-autonomous cleaning device such as a vacuum cleaner 700 relatively belonging to the prior art as shown in FIG. 7, the device is cleaned or debris generated by the piezoelectric debris sensor 704PS located in the vacuum path. The signal 706 is adopted in the main body of the vacuum cleaner 702 by the control microprocessor 708 to generate a user-recognizable signal (such as turning on the indicator light 710) to increase the power from the power system 703. Or it can be a combination of actions (such as turning on a "high power" light and increasing power at the same time).

Aspects of the algorithm for the operation of the debris sensor subsystem are summarized in FIG. As shown therein, the method according to the invention detects a collision with debris and left and right debris signals indicating the presence, amount or volume of debris, and direction (802), debris signal values. Select an operating mode or movement pattern (such as "spot coverage") based on (804), select a movement direction based on the differential left / right debris signal (eg, to the side with more debris). Maneuvering towards) (806), generating a user-recognizable signal indicating the presence or other features of debris (eg, turning on a user-recognizable LED) (808), or operating state, For example, changing or controlling the power (810) can be included.

A further practice of the present invention utilizes the motion of an autonomous cleaner on the floor or other surface to process the debris signal in conjunction with information about the movement of the cleaner to calculate the debris gradient (Figure). 812 in 8). The debris gradient shows the change in the collision count with debris as the autonomous cleaning device moves along a surface. By examining the sign of the gradient (positive or negative in relation to increasing or decreasing debris), the autonomous purifier controller continuously adjusts the appliance path or movement pattern to be most effective at the location of the debris. Can be cleaned (812).

Piezoelectric Sensor As described above, the piezoelectric transducer element can be used in the debris sensor subsystem of the present invention. Piezoelectric sensors have relatively high immunity to adhesions that respond instantaneously to debris collisions and degrade the performance of optical debris sensors typical of conventional techniques.

An example of the piezoelectric debris sensor element 125PS is shown in FIG. Referring to FIG. 4, the piezoelectric debris sensor element 125PS has one or more electrodes connected to the top of a brass disk 402 made of a piezoelectric material having a thickness of 0.20 mm and a diameter of 20 mm. (Total thickness 0.51 mm) can be included, which in turn are mounted on an elastoma pad 404, a plastic dust sensor cap 406, a debris sensor PC board containing the relevant device element 408, and a grounded metal shield 410. And supported by mounting screws (or bolts, or the like) 412 and elastoma grommet 414. The elastomer grommet 414 attenuates the vibration to some extent and provides insulation between the piezoelectric debris sensor element 125PS and the cleaning device.

In the example shown in FIG. 4, a rigid piezoelectric disc of the type typically used for inexpensive acoustic devices can be used. However, flexible piezoelectric films can also be advantageously adopted. Since the film can be manufactured in any shape, its use provides the possibility of sensitivity to debris over the entire cleaning width of the cleaning device, rather than, for example, the sensitivity at the selected location where the disc is located. However, on the contrary, at present, films are more expensive and tend to deteriorate over time. Conversely, brass discs have proven to be very strong.

The typical mounting configuration shown in FIG. 4 is substantially optimized for use in a platform that is mechanically very noisy, such as an autonomous vacuum cleaner as shown in FIG. In such devices, vibration damping or sensor insulation is very effective. However, in the application example including the non-autonomous cleaning device such as the box type vacuum cleaner as shown in FIG. 7, the attenuation mode of the mounting system of FIG. 4 is unnecessary. In non-autonomous cleaning equipment, the alternative mounting system may include heat to secure the piezoelectric element directly to its housing. In any case, an important consideration for achieving improved performance is to reduce the area required to keep the piezoelectric element in place by clamping, bolting, or other means. The smaller the space occupied by this clamped "dead zone", the more sensitive the piezoelectric element.

During operation, the debris thrown up by the cleaning brush assembly (eg, brush 94 in FIG. 3) or flowing through the cleaning path in the cleaning device (eg, vacuum component 104 in FIG. 3) is the piezoelectric debris sensor element 125PS. It may collide with the bottom of the brush, that is, the entire brass part. As shown in FIG. 3, in the robot apparatus 100, the piezoelectric debris sensor element 125PS is substantially located on the axis AX where the main brush 94 and the flapper brush 92 meet along the axis AX, whereby the fine particles 127 are thrown up. It collides with the piezoelectric debris sensor element 125PS with the maximum force.

As is well known, piezoelectric sensors convert mechanical energy (eg, kinetic energy from collision of debris and vibration of brass discs) into electrical energy (in this case, generate an electrical pulse each time the debris collides). It is this electricity that is processed and transmitted to the system controller (eg, microprocessing units 135 in FIGS. 1 and 2 or 708 in FIG. 8) to control or cause changes in operating mode in accordance with the present invention. It is a pulse. Piezoelectric elements are typically designed to be used as audio transducers and, for example, produce beep tones. When an AC voltage is applied, they oscillate mechanically in step with the AC waveform to produce an audible output. Conversely, when they vibrate mechanically, they produce an AC voltage output. In this way, they are employed in the present invention. In particular, when an object first hits the brass surface of the sensor, it bends the disk inward, which produces a voltage pulse.

Filtering However, since the piezoelectric debris sensor element 125PS makes direct or indirect contact with the body through the cleaning device chassis or its mounting system (see FIGS. 3 and 4), when the cleaning device is functioning, the motor, Sensitive to mechanical vibrations normally generated by brushes, fans, and other moving parts. This mechanical vibration causes the sensor to output an unwanted noise signal with a larger amplitude than the signal generated by the small, low mass debris (such as crushed peppercorn) that collides with the sensor. As a result, the sensor produces a composite signal consisting of a low frequency noise component (up to about 16 kHz) and a higher frequency, preferably smaller amplitude, debris collision component (greater than 30 kHz, up to several hundred kHz). Output. Thus, it is useful to provide a means of filtering insignificant signals.

Therefore, as described below, electronic filters are used to significantly attenuate low frequency signal components and improve signal-to-noise performance. Examples of architectures and circuits for such filtering and signal processing devices are described in connection with FIGS. 5 and 6.
IV Signal Processing FIG. 5 is a schematic diagram of a signal processing element of a debris sensor subsystem in one practice of the present invention.

As mentioned above, one purpose of the debris sensor is to enable an autonomous cleaning device to detect debris when it is picked up or when it encounters a location with debris. This information is used as input to make changes in the cleanup behavior or to allow the device to enter the selected behavior or behavioral mode, for example, the spot cleanup mode described above when encountering debris. can. In the non-autonomous cleaning device shown in FIG. 7, the debris signal 706 from the debris sensor 704PS lights a user-recognizable indicator lamp 710 (for example, signals the user that debris has been encountered). Used to increase the power output from the power unit 703 to the cleaning system, or to trigger other behavioral changes or combinations of changes (eg, turning on a user-recognizable "high power" lamp and increasing power at the same time). can.

Further, as mentioned above, the two debris sensor circuit modules (ie, left and right channels such as 125L and 125R in FIG. 1) are the amount of debris picked up by the autonomous cleaning device on the right and left sides of the cleaning head assembly. It can be used to be able to detect the difference between them. For example, if an autonomous cleaner encounters a dust location on its left side, the left debris sensor will show a debris collision and the right sensor will not (or even show a small amount) a debris collision. This differential output steers the device in the direction of debris by the microprocessor controller of the autonomous cleaning device (such as the microprocessing unit 135 of FIGS. 1 and 2) (eg, the left debris sensor has a higher signal than the right debris sensor). Can be used to steer to the left when generating values), or to select a vector of debris direction, or to select a movement pattern or behavior pattern such as spot coverage or otherwise.

As such, FIG. 5 shows one channel (eg, left channel) of a debris sensor subsystem that can include both left and right channels. The right channel is substantially identical and therefore its structure and behavior will be understood from the discussion below.

As shown in FIG. 5, the left channel includes a sensor element (piezoelectric disk) 402, an acoustic vibration filter / RFI filter module 502, a signal amplifier 504, a reference level generator 506, an attenuator 508, an attenuator 508 and a reference level generator. It consists of a comparator 510 for comparing the outputs of the 506 and a pulse stretcher 512. The output from the pulse stretcher 512 is a logic level output signal to the microprocessing unit 135 shown in FIG. 2, a system controller such as a controller suitable for use when selecting behavioral behavior.

The acoustic vibration filter / RFI filter block 502 provides large attenuation (in one embodiment, greater than -45db volt), blocking most of the low frequency, low rate of change mechanical signals and high frequency. , Can be designed to pass high rate of change debris collision signals. However, even if these high frequency signals pass through the filter, they are attenuated, so that amplification by the signal amplifier 504 is required in this way.

In addition to amplifying the desired high frequency debris collision signal, a very small residual mechanical noise signal that passes through the filter is also generated by the motor and radiated into the atmosphere with the electrical noise generated by the amplifier itself. Or amplified with any radio frequency interference (RFI) component picked up by the sensor and its conductors. The high frequency response of the signal amplifier is designed to minimize the amplification of very high frequency RFIs. This constant background noise signal with a frequency component much lower than the desired debris collision signal is fed to the reference level generator 506. The purpose of the reference level generator 506 is to generate the instantaneous peak value of the noise signal, or the reference signal following the envelope. In FIG. 5, the signal of interest, that is, the signal resulting from the collision of debris with the sensor, is also supplied to the reference level generator 506. Thus, the reference level generator 506 is designed to be able to track the instantaneous peak values of high frequency, high rate of change debris collision signals without responding too quickly. The resulting reference signal is used for comparison as described below.

With reference to FIG. 5 again, it can be seen that the signal from the signal amplifier 504 is also supplied to the attenuator 508. Since this is the same signal supplied to the reference level generator 506, it is a decoded signal that contains both the high frequency signal of interest (ie, when debris collides with the sensor) and the low frequency noise. The attenuator 508 reduces the amplitude of this signal, usually less than the amplitude of the signal from the reference level generator 506 when the debris does not collide with the sensor element.

The comparator 510 compares the instantaneous voltage amplitude value of the signal from the attenuator 508 with the signal from the reference level generator 506. Normally, when the cleaning device is in operation and the debris does not collide with the sensor element, the instantaneous voltage coming out of the reference level generator 506 is higher than the voltage coming out of the attenuator 508. As a result, the comparator 510 comes to output a high logic level signal (logic 1), and the signal is inverted by the pulse stretcher 512 to generate a low logic level (logic 0).

However, when the debris collides with the sensor, the voltage from the attenuator 508 exceeds the voltage from the reference level generator 506 (this circuit cannot track the high frequency, high rate of change signal component from the signal amplifier 504). Therefore, the signal generated by the collision of debris is higher in voltage amplitude than the constant background mechanical noise signal which is more severely attenuated by the acoustic vibration filter 502. As a result, the comparator 510 temporarily changes the state to the logic level 0. The pulse stretcher 512 extends this very short (typically less than 10 microseconds) event to a constant 1 millisecond (+ 0.3 mS, -0 mS) event and a system controller (eg, the microprocessing unit 135 of FIG. 2). ) Sufficient time to sample the signal.

When the system controller "sees" this 1-millisecond logic 0 pulse, it interprets the event as a debris collision.

Referring here to the RFI filter section of the acoustic vibration filter / RFI filter 502, this filter functions to attenuate the electrical noise (RFI) radiated at very high frequencies generated by the motor and the motor drive circuit. do.

In summary, the exemplary circuit connected to the sensor element used both amplitude and frequency information to pick up debris collisions (indicating a cleaning device picking up debris), which was also picked up by the sensor element. Distinguish between normal background mechanical noise and radiated radio frequency electrical noise generated by the motor and motor drive circuits. Although not desirable, normal constant background noise is used to establish dynamic criteria for avoiding false debris collision signs while maintaining a good signal-to-noise ratio.

In practice, the mechanical mounting system for the sensor element (see FIG. 4) is also designed to minimize the mechanical acoustic noise vibration coupling that affects the sensor element.

Signal processing circuit (consisting of FIGS. 6A to 6C) FIG. 6 is a detailed schematic diagram of a typical debris sensor circuit. Those familiar with this technique will appreciate that, in other embodiments, signal processing can be performed partially or entirely within the software of the microprocessing unit 135. With reference to FIG. 6, the illustrated example of a suitable signal processing circuit comprises the following elements and operates according to the description below.

The ground-referenced composite signal from the piezoelectric sensor disk (see Piezoelectric Disk 402 in FIG. 4) is supplied to capacitance C1 and attenuates low frequency, acoustic mechanical vibrations that are guided to the sensor via the onboard system. It is input to a 5-pole, high-pass passive RC filter designed to do so. This filter has a -3 dB break point frequency that rolls off at 21.5 kHz, -100 dB / Decade (decrease rate for 10-fold frequency change). The output of this filter is fed to a unipolar, lowpass passive RC filter designed to attenuate any of the very high frequency RFIs. This filter has a -3 dB break point frequency of 1.06 MHz, which rolls off at -20 dB / Decade. The output of this filter is diode clamped by D1 and D2 to protect the sensor element from U1 high voltage transitions in the event of sustained severe collisions that produce voltage pulses larger than the supply rails of the amplifier. The DC bias required for the signal supply operation for the amplifier chain and subsequent comparator circuits is generated by R5 and R6. These two resistance values are selected so that their Thevenin impedance works with C5 to correctly maintain the fifth polar frequency response of the filter.

U1A, U1B, and related components theoretically form a two-step, ac-coupled, non-inverting amplifier with an AC gain of 441. C9 and C10 function to minimize gain at low frequencies, while C7 and C8 function to roll off gain at RFI frequencies. The net theoretical frequency response from the filter input to the amplifier output is -3dB unipolar highpass response at 32.5kHz, -100dB / Decade, and 100kHz, -32dB / Decade, and 5.4MHz, -100dB /. In Decade, it is a two-pole low-pass response having a folding point frequency, and both form a band-pass filter.

The output from the amplifier is split, one output is input to R14 and the other is input to the non-inverting input of U1C. The signal input to R14 is attenuated by the R14-R15 voltage divider and supplied to the inverting input of the comparator U2A. Other signal branches from the output of U1B are supplied to the non-inverting input of amplifier U1C. U1C with U1D, and the components in between (as shown in FIG. 2), form a half-wave, positive peak detector. The attack and decay times are set by R13 and R12, respectively. The output from this circuit is supplied to the non-inverting input of U2A via R16. R16, along with R19, provides hysteresis to improve switching time and noise immunity. The U2A functions to compare the output of the peak detector with the instantaneous value between the R14-R15 attenuator.

Normally, when debris does not collide with the sensor, the output of the peak detector will have its amplitude greater than the output of the attenuator network. When the debris collides with the sensor, a high frequency pulse is generated that is larger than the low frequency mechanical noise signal component and has an amplitude that exits the front-end highpass filter and enters U1A. This signal has a greater amplitude than the signal coming out of the peak detector, even after coming out of the R14-R15 attenuator network, which means that the peak detectors are on R13, C11, and R12. This is due to the inability to track high speed pulses due to component values in the network. The comparator changes the state from high to low as long as the amplitude of the debris collision pulse is greater than the dynamic, noise-generated, reference-level signal emanating from the peak detector. This comparator output pulse is too short for the system controller to see, so a pulse stretcher is used.

The pulse stretcher is a one-shot monostable design with a lockout mechanism, thereby avoiding re-triggering until the end of the timeout period. The output from U2A is supplied to the junction between C13 and Q1. C13 monostablely couples the signal formed by U2C and its associated components. Q1 functions as a lockout by keeping the output of U2A low until the monostability times out. The time-out period is set by the time constant formed by R22, C12, and R18 and the reference level set by the R20-R21 voltage divider. This time can be adjusted for 1 mS, +0.3 mS, and -0.00 mS as specified by the software conditions used by the controller / processor.

The power of the debris sensor circuit is provided by U3 and related components. The U3 is a low power linear regulator that provides a 5 volt output. The unadjusted voltage from the battery mounted on the robot provides a power input.

If necessary, circuit adjustments are set by R14 and R12. With these adjustments, the circuit response can be tuned in a short time.

In this type of generator, the power to the debris sensor circuit printed circuit board (PCB) and the signals from it are transferred to the main board via a shielded cable. Alternatively, the noise filter can be replaced with the use of shielded cable, reducing wiring costs. The cable shielded drain wire can be grounded only on the PCB side of the sensor circuit. This shield does not carry any ground current. Separate conductors in the cable carry the power ground. For noise reduction, the generated sensor PCB should have all components on the top side with a solid ground plane on the bottom side. The sensor PCB should be housed in a mounting assembly with a grounded metal shield covering the top of the substrate to shield the components from radiated noise pickups from the robot motor. Piezoelectric sensor disks can be mounted under the sensor circuit PCB on a suitable mechanical mounting system, as shown in FIG. 4, thereby keeping the connection leads as short as possible for noise immunity. Can be maintained.
V. CONCLUSIONS The invention is not degraded by debris deposition and can be instantaneously sensed and responded to debris collisions, thus responding directly to debris on the floor or other surface of the object to be cleaned. It provides a low-sensitivity debris sensor for fluctuations in power, momentary power, or other operating conditions of the cleaning device.

As described herein, according to the invention, the autonomous cleaning device controls its operation or, for example, directs the device to a more "dirty" location based on the signal generated by the debris sensor. You can choose from multiple modes of operation, movement patterns, or behaviors that respond to detected debris, such as maneuvering.

Debris sensors can also be employed in non-autonomous cleaning devices, which can control, select, or change the operating mode of either autonomous or non-autonomous cleaning devices.

In addition, the disclosed signal processing architectures and circuits are particularly useful in combination with piezoelectric debris sensors and provide high signal-to-noise ratios.

Those familiar with the art will recognize that a wide range of modifications and variations of the present invention are possible within the scope of the present invention. Debris sensors can also be used for purposes and devices other than those described herein. Therefore, the above is merely presented as an example, and the scope of the present invention is limited only by the accompanying claims.

Claims (8)

It is an autonomous cleaning device
A drive system that includes a right wheel assembly and a left wheel assembly,
With a side brush assembly with side brushes and electric motors,
A clean head assembly with an electric motor and brush assembly,
Garbage container and
A chassis that carries the drive system, the side brush assembly, the cleaning head assembly, and the dust container, wherein the side brushes operate to direct particles from the cleaning surface to the cleaning head assembly.
Left and right piezoelectric debris sensors placed between the clean head assembly and the dust container, capable of detecting particles directed to the clean head assembly by the side brush and directed to the dust container by the clean head assembly. The left and right piezoelectric debris sensors,
A control module configured to control the drive system, the control module configured to select the moving direction of the autonomous cleaning device based on the detection result of the particles by the left and right piezoelectric debris sensors. When,
An autonomous cleaning device equipped with. The brush assembly of the clean head assembly includes a flapper brush.
The autonomous cleaning device according to claim 1 . The brush assembly of the clean head assembly further comprises a non-rotating main brush.
The autonomous cleaning device according to claim 2 . It is an autonomous cleaning device
A drive system that includes a right wheel assembly and a left wheel assembly,
A clean head assembly with an electric motor and brush assembly,
Garbage container and
A chassis that carries the drive system, the cleaning head assembly, and the garbage container, wherein the cleaning head assembly operates to direct particles toward the garbage container.
Left and right piezoelectric debris sensors located on the cleaning head assembly side in the cleaning path between the cleaning head assembly and the dust container, capable of detecting particles directed toward the dust container by the cleaning head assembly. With some left and right piezoelectric debris sensors,
A control module configured to control the drive system, the control module configured to select the moving direction of the autonomous cleaning device based on the detection result of the particles by the left and right piezoelectric debris sensors. When,
An autonomous cleaning device equipped with. The brush assembly of the clean head assembly includes a flapper brush.
The autonomous cleaning device according to claim 4 . The brush assembly of the clean head assembly further comprises a non-rotating main brush.
The autonomous cleaning device according to claim 5 . The left and right piezoelectric debris sensors are arranged on the cleaning head assembly side in the cleaning path between the cleaning head assembly and the garbage container.
The autonomous cleaning device according to claim 1 or 4 . The side brush assembly is located in front of the clean head assembly and the left and right piezoelectric debris sensors.
The autonomous cleaning device according to any one of claims 1 to 3 .

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