Full-time anti-sway control method of bridge crane system based on inverter structure

A full-time anti-sway control method of a bridge crane system based on an inverter structure, the bridge crane system comprising an inverter for performing the control method, a position sensor, and at least one motor controlled by the control method, the control method comprising steps of:

• receiving a specified high frequency command and a frequency change time, wherein the frequency change time is an acceleration and deceleration time,
• calculating a time setting range according to a plurality of system parameters and a rope length information of the bridge crane system, wherein the time setting range is the acceleration and deceleration time, wherein
• t
• acc
• /
• dec
• ≥
• J
• sys
• ×
• ω
• rate
• 2
• ⁢
• T
• rate
• ⁢
• and
• ⁢
• t
• acc
• /
• dec
• ≤
• 0.9
• T
• swing
• 2
• ,
• where tacc/dec is the time setting range, ωrate is a rated speed, Trate is a rated torque, Jsys is a system inertia, Tswing is a natural swing period,
• selecting a time setting value within the time setting range,
• dividing the frequency change time into a plurality of time intervals according to the time setting value,
• adjusting an operation frequency command to change between a low frequency command and the specified high frequency command within the plurality of time intervals to generate a frequency change curve,
• acquiring a rotation angle of the at least one motor by the position sensor,
• estimating a swing angle and a swing speed by a swing angle estimation module in a sensorless manner according to the frequency change curve, a gravitational acceleration constant, and the rope length information,
• designing a swing angle processing module by the gravitational acceleration constant and the rope length information,
• generating a frequency correction amount by the swing angle processing module according to the swing angle and the swing speed, and
• superimposing the frequency change curve and the frequency correction amount to generate an anti-sway frequency command to drive the at least one motor.