Operation Theory 454.2 Motion Control ModesNot like motor control is only for positive or negative moving,motion control make the motors run according to a specific speedprofile, path trajectory and synchronous condition with other axes.The following sections describe the motion control modes of thismotion controller could be performed.4.2.1 Coordinate SystemWe use Cartesian coordinate and pulses for the unit of length. Thephysical length depends on mechanical parts and motor’s resolu-tion. For example, if users install a motor on a screw ball. Thepitch of screw ball is 10mm and the pulses needed for a round ofmotor are 10,000 pulses. We can say that one pulse’s physicalunit is equal to 10mm/10,000p =1 micro-meter.Just set a command with 15,000 pulses for motion controller if wewant to move 15mm. How about if we want to move 15.0001mm?Don’t worry about that, the motion controller will keep the residuevalue less than 1 pulse and add it to next command.The motion controller sends incremental pulses to motor drivers. Itmeans that we can only send relative command to motor driver.But we can solve this problem by calculating the differencebetween current position and target position first. Then send thedifferences to motor driver. For example, if current position is1000. We want to move a motor to 9000. User can use an abso-lute command to set a target position of 9000. Inside the motioncontroller, it will get current position 1000 first then calculate thedifference from target position. It gets a result of +8000. So, themotion controller will send 8000 pulses to motor driver to move theposition of 9000.Sometimes, users need to install a linear scale or externalencoder to check machine’s position. But how do you to build this
