Selection of MEMS Accelerometers for Tilt Measurements

Table 2

Initial positions of the accelerometers.

Number #	Case (Table 1)	Initial position of the accelerometer
1	1-A
2	1-A
3	1-B
4	1-B
5	2-A
6	2-B
7	3-B
8	4-B
9	5-A
10	5-B
11	6-A
12	6-B
13	7-A
14	7-B
15	8-A
16	8-B
17	9-A

, , , and : sensitive axes of the accelerometer.
#1–#4: arbitrary position of the accelerometer chip, typically like in 1-A, or 5-A.
#1, #3: when tilt angles < 45° are to be detected with higher sensitivity.
#2, #4: when tilt angles > 45° are to be detected with higher sensitivity.
#3-#4: additionally, expressions , are true while tilted.
#10, #16: if , then (9) and (13) are the same.
#15, #16: at the same time: , .
#17: at the same time: , , , and .