Page 75 - Adaptive Identification and Control of Uncertain Systems with Nonsmooth Dynamics

66 Adaptive Identification and Control of Uncertain Systems with Non-smooth Dynamics

Figure 4.1 Diagram of turntable servo test-rig.

rameter adaptation and thus the tracking performance. However, when
they are too large, the control action may be aggressive.
4) The parameters σ 2 ,σ 3 denote the σ-modification in the adaptive
laws [9]. However, large σ 2 ,σ 3 will suppress the parameter adaptation
speed. Moreover, σ 1 is used to avoid the singularity in control (4.18)
and to guarantee the smoothness of control actions.
Moreover, the structure of HONN is determined by increasing the
number of NN nodes until no further improvement of tracking accuracy
can be observed.

4.4 EXPERIMENTAL VALIDATION

4.4.1 Experimental Setup
To demonstrate the applicability of the proposed method, a turntable motor
servo system is employed as the test-rig [11](Fig. 4.1), which consists of a
permanent-magnet synchronous motor (PMSM, HC-UFS13), an encoder
and pulse width modulation (PWM) amplifiers in the motor drive card
(MR-J2S-10A), a digital signal processing (DSP, TMS3202812) performing
as the controller and a host PC Pentium IV 2.8 GHz PC operating for
display. The proposed control algorithms, including the encoder resolver,
are implemented via a C-program in CCS3.0 (Compiler CCS3.0 from
Texas Instruments) in DSP. In the tests, the angular position is measured
by using an encoder with a resolution of 800 divisions, and a quadrature
encoder pulse (QEP) circuit is used for capturing and converting the speed
and position information of the turntable encoders. A gear transmission