Elmo HARSFEN0602, HARmonica software manual 201, Gain-Scheduling Algorithm

HARSFEN0602ElmoHARmonicaSoftwareManual			PRELIMINARYDRAFT
KV [0]	100
KV[1]	19	Last index used
KV[2]	15	1st block, 2-order
KV[3]	1734476372	Parameter 1 (k1), man
KV[4]	-32	Parameter 1 (k1), exp
KV[5]	1480626866	Parameter 2 (k2), man
KV[6]	-32	Parameter 2 (k2), exp
KV[7]	-1592218865	Parameter 3 (k3), man
KV[8]	-31	Parameter 3 (k3), exp
KV[9]	2104573671	Parameter 4 (k4), man
KV[10]	-32	Parameter 4 (k4), exp
KV[11]	14	2nd block, 1-order
KV[12]	1571662995	Parameter 1 (p), man
KV[13]	-32	Parameter 1 (p), exp
KV[14]	1361652150	Parameter 2 (q), man
KV[15]	-31	Parameter 2 (q), exp
KV[16]	0	End of the filter blocks
KV[17]	0	Reserved
KV[18]	0	Reserved
KV[19]	-1	End of filters

The value of KV[N] parameters for N>19 is not important.

15.5The Gain-Scheduling Algorithm

The gain scheduling (GS) is implemented for speed and position controllers. This means, that the controller parameters (Speed controller KI, KP, Position controller gain, and some links of the high order filter) are changed automatically with the working point of the servo drive.

Gain scheduling solves the following problems:

Low Resolution Position Sensor: When the position sensor has low resolution, the speed is derived from the position data with large time delay, typically half of the time between consecutinve encoder pulses. The speed measurement delay risks the controller stability. In order to maintain stability in low speeds, the controller gains are reduced. For high speed, the controller achieves its full possible bandwidth.

The Harmonica can schedule of the controller gains automatically, as a function of the command to the speed controller. In the speed unit mode, the command to the speed controller is a function of the reference generator only. For the position control modes (UM=4,UM=5) the reference to the speed controller is the sum of the position command derivative, and the output of the position controller.

Load and Posture Variations When controlling an articulated manipulator, the inertia that some of the manipulator motors see varies much with the posture of the manipulator. Resonance frequency may also vary considerably with varying posture or load conditions. By gain scheduling, one can switch the active controller parameters, as a function of posture and load.

The following table describes the programming of 63 controller parameters sets:

Parameters	Name	Description
KG[1]...KG[63]	SpeedKiTable	SpeedKiTable[k] is the speed KI gain for the k'th
		controller
KG[64]...KG[126]	SpeedKpTable	SpeedKpTable[k] is the speed KP gain for the k'th
		controller
KG[127]...KG[189]	PositionKpTable	PositionKpTable[k] is the position KP gain for the
		k'th controller
KG[190]...KG[252]	DoubleLeadBeta	DoubleLeadBeta[k] is the β parameter for the
		double lead element of the k'th controller
KG[253]...KG[315]	DoubleLeadG	DoubleLeadG[k] is the G parameter for the double
		lead element of the k'th controller

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