Control system having error correcting apparatus

A control system for driving a movable component of an apparatus comprising:

• a) a servomotor connected to indirectly drive the movable component from a start position to an end position;
• b) a flag member connected for co-movement with the movable component as the movable component moves from the start position to the end position, the flag member being disposed at a first position when the movable component is at the start position and being disposed at a second position when the movable component is at the end position;
• c) a sensor fixed between the first and second positions and generating an output signal indicative of the flag member reaching a third position between the first and second positions;
• d) a controller for driving the servomotor in accordance with a predetermined motion profile, the predetermined motion profile defining motion characteristics of the movable component as the movable component moves from the start position to the end position within a predetermined time frame, the controller detecting a time of occurrence of the output signal and comparing the time of occurrence with a reference time, comparison between the time of occurrence and the reference time being used by the controller to alter the predetermined motion profile to assist the movable component in reaching the end position by the end of the predetermined time frame;
• and
• e) first and second end position sensors disposed proximate the second position and generating an end position signal to the controller when the flag member reaches the second position, the first and second end position sensors being spaced apart a distance corresponding to a width of the flag member along a direction of travel of the flag member.

A packaging machine comprising:

• a) a plurality of packaging stations, each of the packaging stations executing one or more processes to fill and seal a plurality of packages;
• b) an endless belt conveyor carrying the plurality of packages;
• c) a servomotor connected to drive the endless belt conveyor through an intermediate drive mechanism to thereby transport the plurality of packages between the plurality of packaging stations;
• c) a flag member connected for co-movement with the endless belt conveyor;
• d) a controller for driving the servomotor in accordance with a predetermined motion profile, the predetermined motion profile defining motion characteristics of the endless belt conveyor as the endless belt conveyor moves from an index start position to an index end position within a predetermined time frame;
• e) a sensor fixed between the index start position and the index end position and generating an output signal indicative of the flag member reaching a predetermined position between the index start position and the index end position, the controller detecting a time of occurrence of the output signal and comparing the time of occurrence with a reference time, comparison between the time of occurrence and the reference time being used by the controller to alter the predetermined motion profile to assist the endless belt conveyor in reaching the index end position by the end of the predetermined time frame;
• and
• f) first and second index end position sensors disposed proximate the index end position and generating an index end position signal to the controller when the flag member reaches the index end position, the first and second index end position sensors being spaced apart a distance corresponding to a width of the flag member along a direction of travel of the flag member.

A packaging machine comprising:

• a) a plurality of packaging stations, each of the packaging stations executing one or more processes to fill and seal a plurality of packages;
• b) an endless belt conveyor carrying the plurality of packages;
• c) a servomotor connected to drive the endless belt conveyor through an intermediate drive mechanism to thereby transport the plurality of packages between the plurality of packaging stations;
• d) a flag member connected for co-movement with the endless belt conveyor;
• e) a controller for driving the servomotor in accordance with a predetermined motion profile, the predetermined motion profile defining motion characteristics of the endless belt conveyor as the endless belt conveyor moves from an index start position to an index end position within a predetermined time frame;
• f) a sensor fixed between the index start position and the index end position and generating an output signal indicative of the flag member reaching a predetermined position between the index start position and the index end position, the controller being responsive to the output signal to alter the predetermined motion profile to assist the endless belt conveyor in reaching the index end position by the end of the predetermined time frame;
• and
• g) first and second index end position sensors disposed proximate the index end position and generating an index end position signal to the controller when the flag member reaches the index end position, the first and second index end position sensors being spaced apart a distance corresponding to a width of the flag member along a direction of travel of the flag member.

A packaging machine comprising:

• a) a plurality of packaging stations, each of the packaging stations executing one or more processes to fill and seal a plurality of packages;
• b) an endless belt conveyor carrying the plurality of packages;
• c) a servomotor connected to drive the endless belt conveyor through an intermediate drive mechanism to thereby transport the plurality of packages between the plurality of packaging stations;
• d) a controller for driving the servomotor in accordance with a predetermined indexed motion profile, the predetermined indexed motion profile defining motion characteristics of the endless belt conveyor as the endless belt conveyor moves from an index start position to an index stop position within a predetermined time frame;
• e) a plurality of flag members connected to the endless belt conveyor and disposed from one another a distance substantially equal to the distance that the conveyor travels between the index start position and the index stop position;
• and
• f) first and second sensors disposed proximate the conveyor, the first sensor being fixed between the index start position and the index stop position and generating a first output signal indicative of one of the plurality of flag members reaching a predetermined position between the index start position and the index stop position, the second sensor being disposed at the index stop position and generating a second output signal indicative of said one of the plurality of flag members reaching the index stop position, the controller being responsive to the first output signal to alter the predetermined motion profile to assist the endless belt conveyor in reaching the index stop position, as indicated by the second output signal, by the end of the predetermined time frame.

A packaging machine comprising:

• a) a plurality of packaging stations, each of the packaging stations executing one or more processes to fill and seal a plurality of packages;
• b) an endless belt conveyor carrying the plurality of packages;
• c) a servomotor connected to drive the endless belt conveyor through an intermediate drive mechanism to thereby transport the plurality of packages between the plurality of packaging stations;
• d) a controller for driving the servomotor in accordance with a predetermined indexed motion profile, the predetermined indexed motion profile defining motion characteristics of the endless belt conveyor as the endless belt conveyor moves from an index start position to an index stop position within a predetermined time frame;
• e) a plurality of flag members connected to the endless belt conveyor and disposed from one another a distance substantially equal to the distance that the conveyor travels between the index start position and the index stop position;
• f) first and second sensors disposed proximate the conveyor, the first sensor being fixed between the index start position and the index stop position and generating a first output signal indicative of one of the plurality of flag members reaching a predetermined position between the index start position and the index stop position, the second sensor being disposed at the index stop position and generating a second output signal indicative of said one of the plurality of flag members reaching the index stop position, the controller detecting a time of occurrence of the first output signal and comparing the time of occurrence with a reference time, comparison between the time of occurrence and the reference time being used by the controller to alter the predetermined motion profile to assist the endless belt conveyor in reaching the index stop position, as indicated by the second output signal, by the end of the predetermined time frame.