I have an Autonomous Lawn mower(ALM) which can mow a certain lawn area when that area is bounded by a perimeter wire. Even when that perimeter wire is removed, it has to mow the above mentioned area accurately without slipping into a neighboring area.
Constraints and problems:
- The ALM is an open loop system.
- Differential GPS was tried, but it did not yield proper results.
- Any iterative pattern of area coverage can be used provided the error in each iteration is not added cumulatively which can result in unpredictable error in the end.
I do not expect full fledged solution. But I need a starting point to understand motion planning particularly for unbounded robotics to solve this problem.
I searched on internet to know about the knowledge sources about motion planning but could not get good results. Can anyone guide me to know about such sources preferably books and articles on internet which can help me to solve this problem?
EDIT: Addition of information:
The above picture shows the irregular lawn area which does not have any enclosures and perimeter wire 1.The red mark shows the center point of lawn .
2.The grey area is the initial scaled down area which resembles in shape to the larger area .I could not draw the grey area which exactly resembles the larger green area .
3.The grey lines are the contours which from the tracks to be followed by the lawn mower
1.Using planimeter app for onetime , the shape and dimension of the lawn area (green area) can be known Link:https://play.google.com/store/apps/details?id=com.vistechprojects.planimeter&hl=en
2.Center of polygon can be found by using the method in the following link http://en.wikipedia.org/wiki/Centroid#Centroid_of_polygon
3.Calculation of area of grey shape in the above figure .
4 . Grey shape is the least possible area which can be grazed by the ALM . Grey shape is similar to the green area shape and it is formed when Green area is scaled down
To determine the scale down factor which is a numerical value ‘ n’ (n<1) Where Grey area = n * Green area
Once the Grey area is known , the number of contours or tracks to be grazed by ALM have to be determined manually .
The width of contour is equal to the distance between the blades on the either end i.e. the width which can be grazed by ALM in a single stroke .
Green area = Grey area + area of track 1 + area of track 2 + area of track3 + . . . . . . + area of track n
5.Once the lawn mower is switched on ,it should reach the center of the lawn (red mark showed in the above figure)
6.Then, ALM should graze the least possible area or grey area .
7.After that ALM should Switch to contour circumscribing the grey area . It should continue circumscribing in each track till all the tracks are completed( decision has to be made by validating against the calculated and preset value ' No.of tracks' in ALM)
In this way entire lawn can be mowed without the need of perimeter wire and also ALM would not mow the neighbor’s lawn
a. Enable ALM to reach the center point of the lawn
a. To make ALM mow the grey area accurately
b. To make the ALM switch from one track to track .
c. To bypass the obstacle in track and return to the same track .
When i mentioned this idea to my colleague ,he mentioned the about possible cumulative addition of error in each iteration resulting in an unpredictable error in the end .
I intend to minimize the error and fix the boundary as correct as possible. In fact this deviation should be predictable before it can be corrected .