Two-input control with independent proportional and integral gains for velocity error and velocity feedforward including velocity command limiting

Claim 2

In circuitry for controlling the velocity of a servomotor, in response to a motion command from other circuitry and in response to receiving position information which is fed back from an input device coupled to a servomotor, a servomotor control method comprising: generating a position command from a processor in response to a motion command received by the processor; algebraically summing the position command with position feedback derived from the position information to produce a position error result; generating a velocity command in response to the position error result; inputting the velocity command as a first input to circuitry operating as a proportional-integral velocity regulator; generating a velocity feedforward command from the processor in response to the motion command received by the processor; inputting the velocity feedforward command as a second input to the circuitry operating as the proportional-integral velocity regulator; and generating a command output from the proportional-integral velocity regulator to control the velocity of the servomotor in response to the first and second inputs to the circuitry operating as the proportional-integral regulator.

Claim 3

The method of claim 1, wherein the step of generating the velocity command includes multiplying the velocity feedforward command by a first gain factor to provide a first velocity feedforward product; and controlling the velocity command in response to the first velocity feedforward product; and wherein the step of generating the command output comprises multiplying the velocity feedforward command by a second gain factor to provide a second velocity product; algebraically summing the velocity command with velocity feedback derived from the position information to provide a velocity error result; algebraically summing the second velocity product with the velocity error result to provide a further result; inputting the further result to a proportional branch of the circuitry operating as proportional-integral velocity regulator where the further result is multiplied by a third gain factor to produce a proportional output; inputting the velocity error result to an integral branch of the circuitry operating as proportional-integral velocity regulator to produce an integral output; and algebraically summing the proportional output and integral output to control the command output.

Claim 4

The method of claim 2, wherein the first gain factor controls input of the velocity feedforward command to the integral branch of the proportional-integral velocity regulator; and wherein the second gain factor is provided by subtracting the first gain factor from a fourth gain factor that controls input of the velocity feedforward command to the proportional branch of the proportional-integral velocity regulator.

Claim 5

The method of claim 1, further comprising the step of limiting the velocity command to a predetermined maximum; and further comprising the step of holding the velocity feedforward command constant at the second input to the proportional-integral velocity regulator, in response to the velocity command reaching the predetermined maximum.