  This paper presents an efficient servomotor-aided calibration method for the
triaxial gyroscope. The entire calibration process only requires approximately
one minute, and does not require high-precision equipment. This method is based
on the idea that the measurement of the gyroscope should be equal to the
rotation speed of the servomotor. A six-observation experimental design is
proposed to minimize the maximum variance of the estimated scale factors and
biases. In addition, a fast converging recursive linear least square estimation
method is presented to reduce computational complexity. The simulation results
reflect the robustness of the calibration method under normal and extreme
conditions. We experimentally demonstrate the feasibility of the proposed
method on a robot arm, and implement the method on a microcontroller. We verify
the calibration results of the proposed method by comparing with a traditional
turntable approach, and the experiment indicates that the results of these two
methods are comparable. By comparing the calibrated low-cost gyroscope reading
with the reading from a high-precision gyroscope, we can conclude that our
method significantly increases the gyroscope's accuracy.
