Motion control system and method which includes improved pulse placement for smoother operation

A method for controlling motion of an object, the method comprising:

• determining a placement of pulses for each of a plurality of time intervals, wherein the pulses have an average desired pulse rate across the plurality of time intervals, wherein the quantity of pulses in each of the time intervals is variable, wherein the determining the placement of pulses for each of the plurality of time intervals further comprises:
• determining a placement of pulses for a first time interval at a first rate of pulse generation per time interval, the first rate having a value of 1 plus an integer portion of a desired fractional rate of pulse generation per time interval;
• and
• determining a placement of pulses for a second time interval following the first time interval at a second rate having a value of the integer portion of the desired fractional rate of pulse generation;
• and
• generating the pulses across the time intervals according to the determined placement to drive a motion device to move an object.

A carrier medium comprising program instructions for controlling motion of an object, wherein the program instructions are executable by a motion control system to implement:

• determining a placement of pulses for each of a plurality of time intervals, wherein the pulses have an average desired pulse rate across the plurality of time intervals, wherein the quantity of pulses in each of the time intervals is variable, wherein the determining the placement of pulses for each of the plurality of time intervals further comprises:
• determining a placement of pulses for a first time interval at a first rate of pulse generation per time interval, the first rate having a value of 1 plus an integer portion of a desired fractional rate of pulse generation per time interval;
• and
• determining a placement of pulses for a second time interval following the first time interval at a second rate having a value of the integer portion of the desired fractional rate of pulse generation;
• and
• generating the pulses across the time intervals according to the determined placement to drive a motion device to move an object.

A system for controlling motion of an object, the system comprising:

• a motion device which is operable to move the object;
• a motion control system which is coupled to the motion device, wherein the motion control system includes a processor and a memory medium, wherein the memory medium stores a motion control software program, wherein the motion control software program is executable by the processor to:
• determine a placement of one or more pulses for each of at least a subset of a plurality of time intervals, wherein two or more of the at least a subset of the plurality of time intervals have differing quantities of pulses, wherein each time interval that includes one or more pulses includes a first pulse and a last pulse, and wherein a deadband between the start of the last pulse in the time interval and the end of the time interval is no larger than a largest pulse period in the time interval;
• and
• generate the pulses across the time intervals according to the determined placement to drive the motion device to move the object in a substantially smooth manner.

A system for controlling motion of an object, the system comprising:

• a motion device which is operable to move the object;
• a motion control system which is coupled to the motion device, wherein the motion control system includes a processor and a memory medium, wherein the memory medium stores a motion control software program, wherein the motion control software program is executable by the processor to:
• determine a desired overall average step pulse period for a plurality of time intervals, wherein the desired overall average step pulse period is a non-integer number of clock cycles;
• determine a desired average step pulse period for each of the plurality of time intervals, wherein at least a subset of the desired average step pulse periods have a non-integer number of clock cycles;
• for each interval of the plurality of intervals, perform one or more of:
• determine one or more actual step pulse periods, each having an integer number of clock cycles;
• and
• modify the interval;
• wherein the one or more actual step pulse periods and/or the modified intervals for the plurality of intervals approximate the desired overall average step pulse period over the plurality of time intervals;
• determine a placement of pulses for each of the plurality of time intervals based on one or more of:
• the determined one or more actual step pulse intervals;
• and
• the modified intervals;
• and
• generate the pulses across the plurality of time intervals according to the determined placement to drive the motion device to move the object in a substantially smooth manner.

A method for controlling motion of an object, the method comprising:

• determining a desired overall average step pulse period for a plurality of time intervals, wherein the desired overall average step pulse period is a non-integer number of clock cycles;
• determining a desired average step pulse period for each of the plurality of time intervals, wherein at least a subset of the desired average step pulse periods have a non-integer number of clock cycles;
• for each interval of the plurality of intervals, perform one or more of:
• determining one or more actual step pulse periods, each having an integer number of clock cycles;
• and
• modifying the interval;
• wherein the one or more actual step pulse periods and/or the modified intervals for the plurality of intervals approximate the desired overall average step pulse period over the plurality of time intervals;
• determining a placement of pulses for each of the plurality of time intervals based on one or more of:
• the determined one or more actual step pulse intervals;
• and
• the modified intervals;
• and
• generating the pulses across the plurality of time intervals according to the determined placement to drive a motion device to move the object in a substantially smooth manner.

A carrier medium comprising program instructions for controlling motion of an object, wherein the program instructions are executable by a motion control system to implement:

• determining a desired overall average step pulse period for a plurality of time intervals, wherein the desired overall average step pulse period is a non-integer number of clock cycles;
• determining a desired average step pulse period for each of the plurality of time intervals, wherein at least a subset of the desired average step pulse periods have a non-integer number of clock cycles;
• for each interval of the plurality of intervals, perform one or more of:
• determining one or more actual step pulse periods, each having an integer number of clock cycles;
• and
• modifying the interval;
• wherein the one or more actual step pulse periods and/or the modified intervals for the plurality of intervals approximate the desired overall average step pulse period over the plurality of time intervals;
• determining a placement of pulses for each of the plurality of time intervals based on one or more of:
• the determined one or more actual step pulse intervals;
• and
• the modified intervals;
• and generating the pulses across the plurality of time intervals according to the determined placement to drive a motion device to move the object in a substantially smooth manner.