3.3.6 DRV5055 Off Axis Result
For this device, the sensitivity matching of the sensors requires some normalization by the controller before
performing calculations on the captured analog data. This alignment requires sensors spread about the magnet
by 90° and occupies more space than a single
, and presents additional opportunity for mechanical
misalignment. Despite these drawbacks, it is still possible to follow the same method of harmonic adjustment to
eliminate angle error.
Figure 3-21. DRV5055 Off-Axis Configuration
DRV5055 Off-Axis Mechanical Angle Error
shows the resulting pre-calibrated error captured for this alignment.
The challenge observed using this configuration is that the number of mechanical errors possible in the system
are now doubled with a second sensor. This produces a more complex error profile. Despite this, the same
procedure for calibration applies and yields excellent results.
Angle (deg)
S
yst
em
Angle
Error (deg
)
0
45
90
135
180
225
270
315
360
-10
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
3
4
5
6
7
8
9
10
Mechanical Error
Figure 3-22. DRV5055 Off-Axis Mechanical Angle Error
Hardware, Software, Testing Requirements, and Test Results
30
Absolute Angle Encoder Reference Design With Hall-Effect Sensors for
Precise Motor Position Control
Copyright © 2022 Texas Instruments Incorporated
