FIELD OF THE INVENTION
The present invention relates to a system of autonomous vehicular robotic
device/appliance having a base adapted for mounting of task-specific devices. More
particularly, robotic device with base according to the invention is suitable for mounting
application devices adapted to executing area coverage with limited information about
the surroundings, both for indoor and outdoor applications, under static as well as
dynamic object/obstacle orientation on the area to be scanned. Importantly, the
autonomous robotic device of the present invention having drives and hardware means
that is interfaced with a microcontroller for controlled motion adapted to cover/scan
desired area based on instructions generated through a special algorithm that relies on
instantaneous data about the surroundings received through a number of sensors,
preferably selected from one or more of IR proximity sensors, ultrasonic sensors or
optical proximity sensors, selectively mounted on the frontal side and also below said
robot base. Advantageously, the robot initially explores any indoor area following the
walls to recognize and store the maximum and minimum co-ordinate data it has to
travel, in two co-planer axis directions X & Y, thus there being only four variables for any
given area depending on the initial location of the robot or at any instant of time during
its travel. The initial coordinate values can also be input manually for outdoor application.
The path of the autonomous robot for self exploration is controlled based on the
instantaneous data reception through sensors, without any prior knowledge of
surroundings and thus needing very little memory and processing power requirement.
Importantly also, the autonomous robot device for area coverage with limited information
are adapted for virtual grid formation on the selected area to cover wherein the area is
virtually pre-allocated a plurality of cells of preferred size to thereby enabling the robot to
move fixed amount of length in each step of decreasing rectangular area in an inwardly
spiraling path to complete scanning operation for any area. Also the locations of
obstacles in the area may be identified as 'No entry' cells/state by inputting the
respective co-ordinate data relative to the virtual grid ,so as not to be covered by the
robotic device while scanning. Other than these 'No entry' state cells, we are left with a
number of cells in the area in which the robot device is allowed to move freely. As the
algorithm controlling the movement of robot base works on instantaneous data reception
through the sensors, any shift in the obstacle within the area with initialized boundary,
do not affect dynamic scanning performance of the robotic device. Thus the robotic
device for area coverage with limited information as of the present invention is a simple,

cost-effective, less processing power/memory intensive, yet reliable means of self
exploring robot adapted for a number of indoor and out door applications such as lawn
cleaning, mowing and thus capable to meet variety of domestic and industrial
requirements/application.
BACKGROUND ART
The application of autonomous robots for area coverage for purposes like vacuum
cleaner, floor cleaner or the like, conventionally uses algorithms implemented for
movements during area coverage by said robotic appliance which use map generation for
the area under consideration. These algorithms first explore the area to be covered and
obtain the information regarding the surroundings. A virtual map of the static
surroundings is generated using this data. The robot then covers the area with the help
of this virtual mapped area and storing the related data in memory for deciding the path
of travel avoiding obstacles. This method thus requires huge amount of onboard memory
to store the map. The system alternatively need to communicate with a PC/Laptop for
data storage and processing. Also, the algorithm for conventional robotic appliances is
not capable of accommodating any changes that might take place in real time in the
surroundings, these system or its supporting algorithm are not adapted to cover area
under dynamic environment.
Another type of algorithm used to control the movements of robot for indoor autonomous
robots like floor cleaners is the one which make use of some markers for walls and the
obstacles located in the area. The walls and the obstacles to be marked differently, using
colors and bar codes so that the robot can identify and distinguish walls and obstacles in
order to avoid either traversing same paths once again or collision. However, this
algorithm does not involve the complexity of map generation and related memory
storage and processing requirements.
A further type of conventional algorithm for autonomous robotic appliance such as a lawn
mower that is known in the art which requires the path generation for area coverage to
be defined by the user so that the vehicle can cover the required area in the pattern as
desired by the user. This device thus need some kind of interface to feed the desired

pattern to the robot. This feature is application specific and in most of the applications
this need for a specific pattern to cover the desired area is not compulsory.
Yet another type of algorithm for autonomous robots makes use of a database of the
surrounding stored in a central system, which communicates with the robot and instructs
on next course of action to perform. This method has the limitations of requirements of
high processing and storage capacity in its operating system and also need a
communication channel which makes it an expensive option.
The previous attempts to utilize autonomous robots for various applications have suffered
a number of shortcomings, which will be evident from the following US citations.
US 6671592 titled "autonomous vehicular appliance, especially vacuum cleaner
disclosed about autonomous vehicular appliance is preferably a robotic floor cleaning
appliance, such as a robotic vacuum cleaner. The vehicle has a detection system which
allows the autonomous vehicular appliance to detect the presence of the portable
threshold locator receiving signals from the threshold locators and the autonomous
vehicular appliance uses the received signal to avoid the threshold marked by the locator
to avoid doorways or to of down going stair cases etc.
US 6417641 is granted patent titled "Navigation method and system for autonomous
machines with markers defining the working Area" which discloses in its abstract a
system for operating an autonomous robot for performing tasks, such as lawn mowing,
includes an indicator and a robot configured for detecting the indicator and generating a
map of the working area bounded by the indicator and correcting the position of the
robot in accordance with the generated map of the working area.
US 6615108 is a prior patent titled 'Area coverage with an autonomous robot' that
states about a robotic system for systematically moving about an area to be covered.
The system includes at least one boundary marker located along the outer edge of the
area to be covered, a robot with a navigation system and a sensor unit. The navigation
system navigates the robot in generally straight, parallel lines from an initial location and
turns the robot when the robot encounters one of the boundary markers thereby to
systematically move about the area to be covered. The sensor unit senses proximity to at
least one boundary marker.

US 7324870 is a prior patent titled 'cleaning robot and control method thereof states
about a cleaning robot and a control method thereof in which a cleaning path desired by
the user is recognizable by the cleaning robot, thereby being capable of cleaning an area
desired by the user in a pattern desired by the user. The cleaning robot includes a
running unit to run the cleaning robot, a storage unit for storing a running path, along
which the cleaning robot has learned, and a control unit to recognize the learned running
path of the cleaning robot when a path learning operation is required, to store the
recognized learned running path in the storage unit, and to drive the running unit. The
control unit controls the running unit to cause the cleaning robot to perform the required
cleaning operation while running along the stored learned running path. The user can
directly input, to the cleaning robot, a cleaning path desired by the user, in order to
cause the cleaning robot to perform a cleaning operation while running along the learned
running path. This invention is thus involving high memory storage capacity and
processing power for the cleaning robot device and its control.
US 7289882 is a patent titled 'Robot operating in association with interface surface'
states about a robot adapted to operate in association with an interface surface, having
disposed therein or thereon coded data indicative of an identity of the interface surface in
terms of a plurality of reference points of the interface surface. The robot is adapted to
move over the interface surface, and a sensing device which senses at least some of the
coded data and generates indicating data indicative of the identity of the interface
surface and of a position of the robot on the interface surface, and communication means
to transmit the indicating data to a computer system, which is programmed to select and
execute a computer application based on at least the identity of the interface surface,
and to receive movement instructions from the selected computer application. The
behaviour of the robot is at least in part controlled by the selected computer application.
It is thus evident that the existing algorithms for mobile robotic applications for area
coverage suffer from serious limitations comprising intensive memory and processing
power requirements, lacking in ease of maneuverability of motion, flexibility and
versatility of options under dynamic considerations for floor orientation and/or location of
obstacles such as relocating any object or putting any new obstacle within the area
where the scanning by the robot device is under progress and also having prohibitive
costs with regard to hardware feature requirements for such robotic appliances.

There has therefore been a continuing need in the art to develop a robot device and a
method for its motion control/path generation for area coverage with limited information,
wherein an algorithm for deployment of robotic vehicular appliances adapted to facilitate
area coverage with minimum storage of data and processing power requirement for
information relating to surroundings. Moreover, the need in the related art called for easy
maneuverability/control on vehicular robotic motions under dynamic configuration of area
and objects located therein, so as to necessitate reliance on instantaneous data
minimizing the volume of input storage data relating to limited information for deciding
the course of negotiating selective area coverage in successive incremental steps with
requirement of less processing power and related cost. The robot device and its method
of area coverage along with execution of task specific application is needed to be adapted
for both indoor and out door application, without any complexity involved in map
generation, or signal transmission from threshold locator/transmitter at the inaccessible
area or any such area to be avoided during self-exploration for coverage/scanning, or
need for any boundary marker etc. There has also been a need in the art to enable
uninterrupted motion of the vehicular robot system and method of its self-exploration
even with relocation of objects or placing a new object in the area to be covered under
dynamic scanning situation based on instantaneous data reception.
OBJECTS OF THE INVENTION
The basic object of the present invention is thus directed to a vehicular robotic appliances
adapted for versatile applications comprising the floor cleaner, vacuum cleaner, lawn
mower and the like for area coverage with limited information about surroundings based
on onboard microcontroller and sensors enabled instructions with supporting algorithm
adapted to negotiate the area coverage with minimum memory and processing power
requirement in a cost effective manner and even under dynamic situation with regard to
location of obstacles/accessibility and floor conditions.
Another object of the present invention is directed to vehicular robotic appliances for
area coverage with limited information adapted to perform assigned task based on
onboard microcontroller and sensors enabled instructions with supporting algorithm for
both indoor and outdoor applications in a simple and effective manner.

A further object of the present invention is directed to vehicular robotic appliances for
area coverage with limited information adapted to perform assigned task based on
onboard microcontroller and sensors enabled instructions with supporting algorithm
wherein the area is allocated with a plurality of imaginary cells of desired configuration
arranged by repeating regular geometrical pattern and thereby generating a virtual grid
having variable grid length of cells based on a particular application, to facilitate ease of
area coverage by said robotic appliance by traversing in repeating increment/decrement
mode of traversing path.
A still further object of the present invention is thus directed to a vehicular robotic
appliances for area coverage with limited information based on an algorithm adapted to
negotiate the travel path to execute the assigned task wherein microcontroller execute
the command/instructions based on instantaneous information received through sensors
selectively disposed on the robot platform.
A further object of the present invention is directed to vehicular robotic appliances for
area coverage with limited information based on an algorithm adapted to perform
assigned task by first initializing the X and Y co-ordinate data in relation to the boundary
walls/object/obstacles, including defining some cells out of reach or no entry states with
respect to the pre-defined virtual grid, for an indoor area by self exploration of said robot
in the specified area or by manually inputting necessary data when used for outdoor
application.
A still further object of the present invention is directed to vehicular robotic appliances
for area coverage with limited information adapted to perform assigned task based on
onboard microcontroller and sensors enabled instructions with supporting algorithm that
rely on instantaneous data such that the X and Y co-ordinate data for boundary of area
and the robot location data at any particular instant, thus eliminating the need for large
memory/data storage requirements.
A still further object of the present invention is directed to vehicular robotic appliances
for area coverage with limited information based on an algorithm adapted to perform
assigned task wherein the functioning of robot is based on algorithm that offers flexibility
without the need of any pre-stored data of the surrounding thus needing least memory

and deals with all objects in the area to be covered instantaneously and is thus adapted
to optimize function under both static and dynamic environment.
A still further object of the present invention is directed to vehicular robotic appliances
for area coverage with limited information based on an algorithm adapted to perform
assigned task wherein said algorithm to control the motion or path of travel by the robot
corresponding to any dead end or obstacle location considered or stored as no entry cell
during initial run, either static or in dynamic/changing condition, as it is controlled based
on receiving instantaneous data about the environment.
A still further object of the present invention is directed to vehicular robotic appliances
for area coverage with limited information based on an algorithm adapted to perform
assigned task wherein for indoor application the room walls need not be rectilinear walls
but any pattern curved or straight can be present, without affecting the scanning
performance of the robot.
SUMMARY OF THE INVENTION
The basic aspect of the present invention is thus directed to an autonomous vehicular
robotic device/appliance for area coverage with limited information adapted to scan any
area by self exploration, comprising
a robot means adapted for self-exploration by identifying maximum/minimum co-
ordinate data scanned in real time relating to boundary of an area to be covered/scanned
in relation to initial location of said robot device within the area, and identifying any no
entry area including and/or obstacles/objects/pathways to be avoided therein, wherein
said robot means comprising a task-specific appliance onboard for indoor and/or outdoor
application;
sensor means adapted to receive data relating to surroundings area to be covered;
micro controller means adapted to execute functions generated by algorithm to negotiate
selective path generation of said robot base depending on initialized co-ordinate data for
maximum and minimum length to be covered, location of robot base relative to such co-

ordinates, a virtual grid formation of cells of selective length based on type of
application/task.
Another aspect of the present invention directed to an autonomous vehicular robotic
device/appliance comprising
said robot means adapted for self-exploration by identifying and storing
maximum/minimum co-ordinate data scanning in real time any relating to boundary of
an area to be covered/scanned in relation to initial location of said robot device within the
area, and/or identifying any no entry area including obstacles/objects/pathways to be
avoided therein, wherein said robot means comprising a task-specific appliance onboard
for indoor and/or outdoor application;
said sensors in selective numbers mounted on said robot base selectively disposed and
adapted to receive data relating to surroundings area to be covered;
Said device adapted for receiving the instantaneous data relating to surrounding
dynamically without needing storage of map or pattern and thus needing less memory;
micro controller means adapted to execute instructions generated by a special algorithm
to negotiate selective path generation of said robot base depending on initialized co-
ordinate data for maximum and minimum length to be covered, location of robot base
relative to such co-ordinates, a virtual grid formation of cells of selective length based on
type of application/task;
A further aspect of the present invention is directed to an autonomous vehicular robotic
device/appliance, wherein said sensors are selected from IR proximity sensors, ultrasonic
or optical proximity sensors.
A still further aspect of the present invention is directed to an autonomous vehicular
robotic device/appliance wherein preferably five sensors mounted on said robot base
comprising 3 sensors placed forward, right and left and 2 sensors placed below the base
facing towards the floor, on the front right and front left side for receiving data relating to
the surrounding for desired motion control/task execution during self-exploration.
A still further aspect of the present invention directed to an autonomous vehicular robotic
device/appliance wherein said micro controller is preferably a conventional micro

controller adapted to execute instructions generated by said algorithm for desired motion
control of robot base for desired area coverage/scanning and performance control of
task-specific appliance onboard, needing less processing power.
A still further aspect of the present invention is directed to a method for area coverage
with limited information by using the autonomous vehicular robotic device/appliance
adapted to scan any desired area by self exploration comprising the steps of exploring
the area for the first time by following the boundary walls for indoor application and
thereby identifying and storing in memory initial data relating to maximum and minimum
distance it need to travel in X and Y directions for the given area and thus enabling input
of four variables, depending on the initial location of the robot device.
A still further aspect of the present invention is directed to said a method for area
coverage, wherein for outdoor application of said robot device, the initial co-ordinate data
corresponding to said four variables are manually put in to the system.
A still further aspect of the present invention is directed to a method for area coverage,
adapted to scan area by self exploration, wherein once the initial data comprising four
variables/co-ordinate values are fixed, identified and stored in memory, the area is
assumed to be inscribed in substantially a rectangle of length [(Max X) minus (Min X) +
1)] and breadth [(Max Y) minus (Min Y) + 1)], that is to be covered by said robot device.
Another aspect of the present invention directed to a method for area coverage, adapted
to scan any area by self exploration, comprising dividing said defined area to be covered
into a virtual grid comprising a plurality of cells having selective variable length decided
by said robot, depending on (a) nature of appliance onboard and (b) optimal scanning
requirement for a given area to be covered, for any particular type of sensor used in said
robot device.
According to yet another aspect of the present invention directed to said method for area
coverage, adapted to scan any area by self exploration, wherein a particular location at
which said robot is located at any instant is a state and as it moves on, the robot
changes its state.

Another important aspect of the present invention directed to a method for area
coverage, adapted to scan area by self exploration, wherein in said virtual grid formation
comprising a plurality of cells of desired dimensions so that the co-ordinate data relating
to some cells representing location of obstacles or inaccessible area are identified either
by manual input for existing obstacle areas or scanned in real time during area coverage
under progress, such that the robot device avoids such 'No entry cells' as areas not for
scanning.
A still further aspect of the present invention directed to said method for area coverage
with limited information by the autonomous vehicular Robot device/appliance as claimed
in any one of claims 6 to 11, adapted to scan area by self exploration, wherein said
robotic device is adapted to be interfaced with said sensors and micro controller means
for motion control of robot device such that on generation of necessary instructions said
robot device is adapted to negotiate path for self exploration for desired area coverage
by starting initial run along the wall and then reducing the area by one unit on either side
of the initial dimensions along length and breadth of the rectangle and such reduction is
repeated at each successive self exploration path generated so that the robot moves a
fixed length of path in each step, and thus negotiating motion through a modified
spiraling inwards path, until only one cell is left or all cells remaining uncovered are the
'No entry cells', ensuring complete scanning/covering the desired area.
According to a further aspect of the present invention directed to said method for area
coverage, adapted to scan area by self exploration, wherein said robot device relies on
instantaneous data relating to surroundings, either static or dynamic environment, and
thus allows free movement of any apparatus/object within the room or bring in new
object without making any special changes for the robot device.
A still further aspect of the present invention is directed to a method for area coverage,
adapted to scan area by self exploration, wherein in indoor application of said robot
device, the walls are selected to be of any shape or pattern comprising, rectilinear,
curved or other and still enabling the area being scanned by said robot device.
According to an yet further aspect of the present invention directed to said method for
area coverage, adapted to scan area by self exploration, involving adequate flexibility
free of any use of stored maps or boundary markers or any signal transmitter at

locations of obstacles or out of reach portions or inaccessible areas including, doorway,
passages and the top- downward going stair cases involving real time scanning and not
stored in the memory thus sustaining the applicability of the algorithm in dynamic
situations.
A still further aspect of the present invention is directed to said method for area coverage
involving scanning any area by self exploration, with said robot device adapted for
execution of task-specific performance of appliances comprising any one of vacuum
cleaning, floor cleaning, lawn mowing, mine detection and the like using appropriate
device mounted on said robot base.
The present invention and its objects and advantages are described in greater details
with reference to the accompanying non limiting illustrative figures and example.
BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
Figure 1: is the schematic illustration of an arbitrary area having some obstacles inside
the area which is to be covered by the robotic appliance of the present invention with
limited information based on an algorithm adapted for both static and dynamic object
orientation in said area.
Figure 2: is the schematic illustration of the virtual grid formation by allocating a
plurality of pre allocated cells of preferred length including defining the 'no entry states'
for location of obstacles in the area to be covered.
DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE
ACCOMPANYING FIGURES
The present invention is directed to an autonomous vehicular robotic platform adapted
for mounting of various appliances to execute desired tasks, both indoor and outdoor
application, such as the floor cleaner, vacuum cleaner, lawn mower, mine detector and

the like, whereby an algorithm enable said robot vehicle to operate within definite area to
be covered to performed the assigned task avoiding obstacle under both static and
dynamic situations. The robot further rely exclusively on instantaneous co-ordinates data
of any indoor area by negotiating an initial self-exploration run and the information
relating to location of any obstacle. For out door application to cover area without any
boundary wall, such co-ordinate or obstacle related data need to be manually input The
area to be covered is allocated a plurality of cells of desired dimension forming a virtual
grid covering the area wherein presence of any initial obstacles or eliminating some area
from scanning are assigned 'no entry states' by manual input of co-ordinate data which
the robot will exclude from coverage during its traverse. The algorithm used to execute
instruction for the control of robot movements also advantageously enable coverage with
respect to any change in location of an initial obstacle or any interim introduction of new
obstacle in the area to be covered, by relying on instantaneous data collected through
selectively placed sensors and processed through a micro controller mounted onboard.
Thus the device and method according to the present invention is directed to area
coverage by vehicular robotic appliances with limited information and without needing
any historical data about the surroundings, in a simple and less costly manner involving
requirement of minimum memory storage and processing power.
Reference is first invite to the accompanying Figure 1, that illustrates the area to be
covered by the robot device of the invention. The robot base with any device mounted on
it to carryout specific task, is adapted to operate based on instructions generated by a
special algorithm that is functionally interfaced with sensor based input data and
microcontroller based control commands. The area schematically shows presence of
obstacles within its boundary, which constitute the basic static information at the initial
start position, for the robot to store input data and self exploration for initialization of the
co-ordinate data for the boundary of a closed area for coverage.
The robot device of the present invention thus perform the area coverage with limited
information data input and control by a set of hardware implements onboard and also a
special algorithm adapted to send instruction/command to control robot motion for
desired area coverage through a microcontroller. The autonomous robot base having said
micro controller to execute instructions supported by said algorithm, is achieved by a
conventional and simple 8051 based controller as good processing power is not
demanded, based on data inputs from a number of sensors, preferably five sensors

mounted on the base. The sensors are selected preferably from conventional IR
proximity sensors or ultrasonic or optical proximity sensors. The device comprises
preferably five sensors selectively disposed on base, for the desired boundary/object
detection and motion course determination purpose. Three such sensors are mounted
forward right and left, and other two sensors placed below the base facing towards the
floor, on the front right and left sides. Any mechanism/equipment can be mounted on the
robotic base for making the device task-specific viz. vacuum cleaner, floor cleaner, lawn
mower, mine detector and the like.
The steps of area coverage by the vehicular robot device according to the present
invention enabled by instruction set through a special algorithm, either for indoor or for
outdoor applications are carried out as follows:
a. Virtual grid formation:
Reference is now invited to the accompanying Figure 2 that illustrates the principle of
virtual grid formation high lighting the 'No entry' states, to facilitate executing command
generated by the algorithm cooperatively with the sensors and the microcontroller in
desired increment/decrement mode of path generation by the robot on motion, starting
with initialized co-ordinate data of boundary and the obstacles/inaccessible portions
located therein. The area to be covered is divided into a number of virtual cells arranged
in an array forming a virtual grid. The cell lengths are selected based on specific
application and requirements of scanning the area and the obstacles located within.
When the robot is in a particular location it is called a state and as it moves it go on
changing the state. The cells where any obstacle is located is termed as a 'No entry'
state. The robot is left with the remaining cells for free motion in areas other than the
'No entry' state cells.
b. Self-exploration by the robotic appliance:
The robot at first (and only for the first time) explores the area to be covered by
following the surrounding walls and selects and store the values of maximum and
minimum co-ordinates it has to travel in X and Y axis directions. Thus there are four
variables for any given area depending on the initial location of the robot. These values
can alternatively be supplied manually for outdoor application of the robotic device. Once
this initialization of co-ordinate data have been fixed, any given area to be covered can

be assumed to be inscribed in a rectangle of length [(Max X) minus (Min X) + 1)] and
breadth [(Max Y) minus (Min Y) + 1)], having some 'No entry' state cells that are out of
reach of the robot device.
Referring back to the Figure 1 showing schematically the example of a given area to be
covered having some obstacles located within the area, if the robot starts to move from
the right lower corner, such that Max. X =0, Min. X= -6 and Max. Y=7 and Min. Y=0,
thus defining the given area in terms of a rectangular configuration of size 7x8 units that
enclose the area. When the area is without walls, the input for these variables can be
provided manually and the robot is placed accordingly. The robot assume the "No entry'
cells beyond these given dimensions and thus out of reach or not to be traversed. For out
door application of the robot base, the boundary data or initial location data of robot is
manually put into the memory of the processor/micro controller.
c. Area Coverage method:
The robot starts to move from the initial location within the area corresponding to which
the four variables have been identified and stored in the starting step, it covers the
boundary of the room following the walls. It first executes the initial self exploration state
for initialization of the co-ordinate data for the boundary walls. In the next step the
dimension of the rectangle is reduced by 1 unit on each side so that the space available
for free exploration by the robot is now reduced to that extent. This reduction takes place
in continued successive steps till only one cell is left or till all locations left are the 'No
entry' cells. The robotic device according to the present invention is capable of executing
a spiraling inward path starting from boundary walls. Once the robot reaches this central
cell or vNo entry' state after covering the entire area, the robot can either retrace its path
or go to initial position directly and hibernate and can be activated again later when
needed.
The vehicular robot base according to the present invention and the method of
implementing area coverage based on initialized input data and the sensor based
instantaneous input data about surrounding, processed by the micro-controller to
generate a selective motion path by the vehicular robot device, based on instructions
received through a special purpose algorithm, is unique, novel and simple needing no
mapping and thus saving on requirement of memory and the processing power.

The algorithm supporting the logic and generating instructions for motion control of the
robot base is independent of the grid cell length. We can change the grid cell length and
best optical scanning is achieved for a particular type of sensor, thus making the
algorithm versatile one. The advantage of the method of self-exploration of the robot
base with respect to a virtual grid formation is illustrated with respect to Example 1.
Example 1:
The benefit of variable cell length/size of virtual grid according to the invention and its
supporting algorithm optimizes the motion path for area coverage by the robot device.
(i) For application in mine detecting robots that uses an appropriate sensor to
detect mines in outdoor application, usually the range of reception of this
sensor is in the order of a circle of radius of 3 meters or more, whereas the
robot base dimension used for covering the area is 30cm x 30cm. Now, if the
grid cell length is set at 4.5 meters for the virtual grid formation, the robot can
scan the whole area without actually passing through the whole space as the
sensor reach is 3 meters, it will cover the entire area while scanning for mine
detection.
(ii) For a robot device used for vacuum cleaning purpose in indoor application, the
device has to essentially scan the entire area to remove dust/dirt. The grid
size is thus maintained in this case as small as 30 cm, so that the robot base
having dimension of 30cmx 30cm can scan all cells of the virtual grid to cover
all space in the defined area for coverage.
The robot by virtue of this algorithm is capable of scanning an area, indoor or outdoor,
whereby it is free to move any apparatus/object within the room or bring in new objects
without requiring any change in the robot base configuration or its hardware features.
For outdoor application, the robot can function equally efficiently as indoors, only
necessity is that the maximum values for the co-ordinate data for the perimeter have to
be manually put in to the system. Further, the free movement of the robot base can be
easily constrained to a room or away from staircase by mannual input of co-ordinate data
or by real time scanned data during the initial run by the robot so that the robot does not
go near such areas again. The device does not need any transmitter module fixed on site

to make the robot aware of existence of a dead end or 'No entry cell'. Advantageously
also, for any indoor application the boundary walls need not be rectilinear walls but can
be of any configuration/pattern such as curved, or straight without any difficulty of
scanning.
It is thus possible by way of the present invention to develop a vehicular robot device for
area coverage with limited information having onboard micro controller and sensors for
instantaneous reception of data relating to surrounding, surface condition,
obstacles/objects within the area being covered wherein the robot is adapted to initialize
the co-ordinate data by self exploration for any indoor application and its location data in
relation to the boundary for maximum and minimum travel requirements. Thus the
memory storage capacity requirement is minimized and also the processing power
requirement is low making the area coverage device and method simple and cost
effective for any kind of appliance on board the robot base such as the floor cleaner,
vacuum cleaner, mine detector, lawn mower and the like adapted to be independently
carried out by the self exploring robot device. More advantageously, the robot device for
area coverage with limited information about surrounding, for both indoor and outdoor
application is having motion control and path generation method supported by an
algorithm supporting the microcontroller and sensor based input processing, such that it
can negotiate traverse path following a virtual grid formed by dividing the area into a
number of regular arrangement of rectangular cells of variable cell length, depending on
the nature of appliance the robot base undertakes to assigned execute task. The robot
device and its operating algorithm thus enable area coverage to accomplish a number of
specified task through on board appliance for both the indoor area with surrounding walls
of any configuration-rectilinear or curved and also out door area of any size and shape
with minimum data storage and processing power requirement and even with presence
of obstacle or inaccessible portions and any subsequent change in the position of the
obstacles due to the inbuilt capacity of the robot system to operate relying on
instantaneous data.

We claim:
1. An autonomous vehicular robotic device/appliance for area coverage with limited
information adapted to scan any area by self exploration, comprising
a robot means adapted for self-exploration by identifying maximum/minimum co-
ordinate data scanned in real time, relating to boundary of an area to be
covered/scanned in relation to initial location of said robot device within the area,
and identifying any no entry area including obstacles/objects/pathways to be
avoided therein, wherein said robot base having a task-specific appliance onboard
for indoor and/or outdoor application;
sensor means adapted to receive data relating to surroundings area to be
covered
micro controller means adapted to execute functions generated by algorithm to
negotiate selective path generation of said robot base depending on initialized co-
ordinate data for maximum and minimum length to be covered, location of robot
base relative to such co-ordinates, a virtual grid formation of cells of selective
length based on type of application/task.
2. An autonomous vehicular robotic device/appliance as claimed in claim 1
comprising
said robot means adapted for self-exploration by identifying maximum/minimum
co-ordinate data scanned in real time, relating to boundary of an area to be
covered/scanned in relation to initial location of said robot device within the area,
and/or identifying any no entry area including obstacles/objects/pathways to be
avoided therein, wherein said robot means comprise a task-specific appliance
onboard for indoor and/or outdoor application;
said sensors in selective numbers mounted on said robot base selectively disposed
and adapted to receive data relating to surroundings area to be covered;

Said device adapted for receiving the instantaneous data relating to surrounding
dynamically without needing storage of map or pattern and thus needing less
memory;
micro controller means adapted to execute instructions generated by a special
algorithm to negotiate selective path generation of said robot base depending on
initialized co-ordinate data for maximum and minimum length to be covered,
location of robot base relative to such co-ordinates, a virtual grid formation of
cells of selective length based on type of application/task;
3. An autonomous vehicular robotic device/appliance as claimed in claim 1, wherein
said sensors are selected from IR proximity sensors, ultrasonic or optical
proximity sensors.
4. An autonomous vehicular robotic device/appliance as claimed in anyone of claims
1 or claim 2 wherein preferably five sensors mounted on said robot base
comprising 3 sensors placed forward, right and left and 2 sensors placed below
the base facing towards the floor, on the front right and front left side for
receiving data relating to the surrounding for desired motion control during self-
exploration.
5. An autonomous vehicular robotic device/appliance as claimed in anyone of claims
1 to 3 wherein said micro controller is preferably a conventional micro controller
adapted to execute instructions generated by said algorithm for desired motion
control of robot base for desired area coverage/scanning and performance control
of task-specific appliance onboard, needing less processing power.
6. A method for area coverage with limited information by using the autonomous
vehicular robotic device/appliance as claimed in any one of claims 1 to 5 adapted
to scan any desired area by self exploration comprising the steps of exploring
the area for the first time by following the boundary walls for indoor application
and thereby identifying and storing in memory initial data relating to maximum
and minimum distance it need to travel in X and Y directions for the given area
and thus enabling input of four variables, depending on the initial location of the
robot device.

7. A method for area coverage as claimed in claim 6, wherein for outdoor application
of said robot device, the initial co-ordinate data corresponding to said four
variables are manually put in to the system.
8. A method for area coverage as claimed in anyone of claims 6 or 7, adapted to
scan area by self exploration, wherein once the initial data comprising four
variables/co-ordinate values are fixed, identified and stored in memory, the area
is assumed to be inscribed in substantially a rectangle of length [(Max X) minus
(Min X) + 1)] and breadth [(Max Y) minus (Min Y) + 1)], that is to be covered by
said robot device.
9. A method for area coverage as claimed in any one of claims 6 to 8, adapted to
scan any area by self exploration, comprising dividing said defined area to be
covered into a virtual grid comprising a plurality of cells having selective variable
length decided by said robot, depending on (a) nature of appliance onboard and
(b) optimal scanning requirement for a given area to be covered, for any
particular type of sensor used in said robot device.
10. A method for area coverage as claimed in any one of claims 6 to 9, adapted to
scan any area by self exploration, wherein a particular location at which said robot
is located at any instant is a state and as it moves on, the robot changes its state.
11. A method for area coverage as claimed in any one of claims 6 to 10, adapted to
scan area by self exploration, wherein in said virtual grid formation comprising a
plurality of cells of desired dimensions so that the co-ordinate data relating to
some cells representing location of obstacles or inaccessible area are identified
either by manual input for existing obstacles or scanned in real time during area
coverage under progress, such that the robot device avoids such 'No entry cells'
as areas not for scanning.
12. A method for area coverage with limited information by the autonomous vehicular
Robot device/appliance as claimed in any one of claims 6 to 11, adapted to scan
area by self exploration, wherein said robotic device is adapted to be interfaced
with said sensors and micro controller means for motion control of robot device

such that on generation of necessary instructions said robot device is adapted to
negotiate path for self exploration for desired area coverage by starting initial run
along the wall and then reducing the area by one unit on either side of the initial
dimensions along length and breadth of the rectangle and such reduction is
repeated at each successive self exploration path generated so that the robot
moves a fixed length of path in each step, and thus negotiating motion through a
modified spiraling inwards path, until only one cell is left or all cells remaining
uncovered are the 'No entry cells', ensuring complete scanning/covering the
desired area.
13. A method for area coverage as claimed in any one of claims 6 to 12, adapted to
scan area by self exploration, wherein said robot device relies on instantaneous
data relating to surroundings, either static or dynamic environment, and thus
allows free movement of any apparatus/object within the room or bring in new
object without making any special changes for the robot device.
14. A method for area coverage as claimed in any one of claims 6 to 13, adapted to
scan area by self exploration, wherein in indoor application of said robot device,
the walls are selected to be of any shape or pattern comprising, rectilinear, curved
or other and still enabling the area being scanned by said robot device.
15. A method for area coverage as claimed in any one of claims 6 to 14, adapted to
scan area by self exploration, involving adequate flexibility free of any use of
stored maps or boundary markers or any signal transmitter at locations of
obstacles or out of reach portions or inaccessible areas including, doorway,
passages and the top downward going stair cases and the scanning is selectively
adapted to be limited to desired access areas and avoiding any area preassigned
'No entry state cells' based on initial manual input data corresponding to any
existing obstacles or scanned in real time and not stored in the memory thus
sustaining the applicability of the algorithm in dynamic situations

16. A method for area coverage as claimed in any one of claims 6 or 15 involving
scanning any area by self exploration, with said robot device adapted for
execution of task-specific performance of appliances comprising any one of
vacuum cleaning, floor cleaning, lawn mowing, mine detection and the like using
appropriate device mounted on said robot base.
17. An autonomous vehicular robotic device/appliance for area coverage with limited
information adapted to scan area by self exploration and a method of execution of
such scanning/area coverage with minimum memory and processing power
requirement as herein described with reference to the accompanying non-limiting
illustrative figures and examples.

An autonomous vehicular robotic device/appliance having a movable base adapted for
mounting of task-specific devices for indoor and/or outdoor application. Importantly, a
special algorithm sends instruction for self-exploration by the robotic device relying on
instantaneous data received through sensors, mounted on the robotic base and
processed through a microcontroller onboard. Advantageously, the robot decides the
maximum and minimum distance it has to travel by self exploration along walls, thus
needing only four variables for any given area at any instant of time during its travel or
by manual input of initial data for outdoor application. The robot device thus needs very
little memory and processing power requirement. Importantly, the algorithm adapted to
form virtual grid for any area with a plurality of cells of preferred size to thereby enabling
the robot to move fixed amount of length in each repeating steps in an inwardly spiraling
path. The obstacles are identified as 'No entry' cells/state in said grid. Thus the robotic
device is a simple, cost-effective yet reliable means needing less processing
power/memory for self exploration of any area for indoor and outdoor applications such
as floor cleaning, lawn mowing and thus capable to meet variety of domestic and
industrial requirements/application.