Design concept 1

-This design has got wheels and works on hydraulics mechanism.As it contains wheels,the bot is not mobile on all kinds of surfaces.

Design concept 2

-This design also works on hydraulics mechanism but it has got chain rollers which helps in mobility of the bot on all kinds of surfaces easily.

Design concept 3

-This design has got chain rollers as well as storage box, which can store the excavated material on it's own.It works on hydraulics mechanism.

Design concept 4

-This design has got wheels on it as well as storage box, which can store the excavated material on it's own.It works on the principle of screw mechanism.

Objectives	Weightage
Mobility	9
Strong outer body	8
High battery life	7
Ease of operation	5
Storage	6

Pugh Chart

Objectives	Weightage	Design Idea 1	Design idea 2	Design idea 3	Design idea 4
Mobility	9	-	Datum	0	-
Strong outer body	8	+	Datum	+	+
High battery life	7	+	Datum	-	+
Ease of operation	5	+	Datum	-	+
Storage	6	--	Datum	+	++
+ score		20	0	14	32
- score		21	0	12	9
Total		-1	0	2	23

Justification

Design idea no.	Objectives	Score given	Justification
1	Mobility	-	It has wheels which are not suitable for all kinds of surfaces
1	Stronger outer body	+	Completely made up of metal
1	High battery life	+	Wheels consume less power as compared to chain rollers
1	Ease of operation	+	Wheels are easy to control as it can move to desired direction easily
1	Storage	--	No self storage
2	Mobility	Datum	-
2	Stronger outer body	Datum	-
2	High battery life	Datum	-
2	Ease of operation	Datum	-
2	Storage	Datum	-
3	Mobility	0	It has chain rollers thus it is same as that of the datum
3	Stronger outer body	+	Outer body is made up of metal
3	High battery life	-	Needs more power as it has got storage box on it
3	Ease of operation	-	Chain drive is difficult to operate
3	Storage	+	Has its own storage box
4	Mobility	-	It has wheels which are not suitable for all kinds of surfaces
4	Stronger outer body	+	Made up of metal body
4	High battery life	+	Smaller in size thus consumes less power
4	Ease of operation	+	As it includes screw mechanism,it is easier to operate
4	Storage	++	Has got ample space for storage

Identify Sub systems

Sl no.	Sub system name
1	Receiving signal
2	Movement
3	Excavation
4	Storage

Interaction details

Sub system 1

	Sub system 2	Sub system 3	Sub system 4
Energy interaction	No	No	No
Data interaction	Yes	Yes	Yes
Material interaction	Yes	Yes	No
Spatial interaction	No	No	No

Sub system 2

	Sub system 1	Sub system 3	Sub system 4
Energy interaction	No	Yes	No
Data interaction	Yes	No	No
Material interaction	Yes	Yes	No
Spatial interaction	No	No	No

Sub system 3

	Sub system 1	Sub system 2	Sub system 4
Energy interaction	No	Yes	No
Data interaction	Yes	Yes	No
Material interaction	No	Yes	No
Spatial interaction	No	No	No

Sub system 4

	Sub system 1	Sub system 2	Sub system 4
Energy interaction	No	No	No
Data interaction	No	No	No
Material interaction	No	No	No
Spatial interaction	No	No	No