XELA Robotics April 18, 2024 uSPa11,21,22
uSPa11, 21, 22
1 Overview
• Hall-eect-based tactile sensor
• Multi-taxel (distributed) sensing
• 3-axis force measurement per taxel
• So skin
• Up to 500 Hz of sampling rate
• Built-in temperature dri compensation
• 2 dierent sensitivities (pre-programmed)
2 Technical specification
uSPa11 uSPa21 uSPa22
Value Unit
Power voltage (microcontroller) 5 V
Power voltage (sensor) 2.2 ∼ 3.6 V
Current consumption (microcontroller) 11.6 ∼ 26 mA
Current consumption (sensor) 6.1 7.9 17.3 mA
Sampling frequency 500 250 125 Hz
Dimensions (without cable) 7 x 7.5 x 4.7 11.1 x 6.3 x 4.7 11.1 x 11.1 x 4.7 mm
Measurement range (x & y)
∗2
± 8033 LSB
Measurement range (z)
∗2
+19099 LSB
Noise (x & y)
∗2
± 0.05 %
Noise (z)
∗2
± 0.05 %
Number of taxels 1 2 4 −−
*2 In case of sensitivity H
3 Sensitivity/ Resolution
uSPa11, uSPa21, and uSPa22 feature two distinct sensitivity seings denoted by the leers "L" or "H". This sensitivity configuration
dictates the measurement range of the sensor. Detailed information regarding the sensor’s response for a single sensing point
(i.e., when force is applied to one taxel) is provided in Fig.1 and 2. The default seing for sensitivity across all standard models is
"H". For inquiries regarding sensor modules with alternative sensitivity seings, please contact XELA Robotics.
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XELA Robotics April 18, 2024 uSPa11,21,22
0 2 4 6 8 10 12 14
Force (N)
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
20000
uSkin Raw Output (LSB)
Z-axis S="L"
Z-axis S="H"
Figure 1: Sensor’s normal force (z-axis) output with two sensitivity seings.
-2.5 -2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5
Force (N)
-10000
-8000
-6000
-4000
-2000
0
2000
4000
6000
8000
10000
uSkin Raw Output (LSB)
X-axis S="L"
Y-axis S="L"
X-axis S="H"
Y-axis S="H"
Figure 2:
Sensor’s shear forces (x and y-axis) output with two sensitivity seings.
2