Apparatus and method for controlling tape tension using acceleration and average tension deviation information to adjust motor drive currents

An apparatus for transporting a tape between two reels comprising:

• a reel driving system including to motors for driving said reels, respectively and means for energizing said motors thereby effecting transportation of the tape between said reels,
• means for measuring a time interval required for the tape to reach a predetermined reference speed from a given speed, while the tape is mounted to the reels for transportation between them,
• means for measuring an actual value of a tension applied to the tape during said time interval and obtaining a tension deviation of the actual tension value from a desired tension value,
• means for calculating correction values of factors relating to determination of driving commands to said reel driving motors, respectively, as energized by said reel driving system, based on said time interval and said tension deviation,
• means for storing said correction values to be used in a succeeding transportation of the tape, and
• means for correcting said factors based on said stored correction values, thereby correcting the driving commands of the respective reel motors in the succeeding transportation of the tape.

A method for controlling transportation of a tape between two reels in a tape transportation system comprising two motors for driving said reels, respectively and means for energizing said motors thereby effecting transportation of the tape, said method comprising the steps of:

• measuring a time interval required for the tape to reach a predetermined reference speed from a given speed while the tape is mounted to the reels and the driving motors are energized for transportation of the tape between said reels,
• measuring the actual value of a tension applied to the tape during said time interval and obtaining a tension deviation of the measured tension value from a desired tension value,
• calculating correction values of factors relating to driving currents of said reel driving motors, respectively, as energized by said tape transportation system, based on said time interval and said tension deviation,
• storing said correction values to be used in a succeeding transportation of the tape, and
• correcting said factors based on said stored correction values, thereby correcting the driving currents of the respective reel motors in the succeeding transportation of the tape.

A tape transport method in a tape transport apparatus of the type which comprises two reels on which the tape is mounted for transport therebetween, driving motors for driving the reels, respectively, motor driving means for energizing said motors based on driving commands applied thereto and means for calculating and controlling said driving commands based on tape radial of said reels, said tape transport method comprising the steps of:

• obtaining an interval required for one of the reels to reach a predetermined reference speed from stop state upon starting the tape to move for transport between the reels and an average tension error of said tape within said time interval;
• calculating acceleration errors of two reel drive systems by use of said time interval and said average tension error, respectively;
• and
• correcting said drive commands to be applied to said motor driving means so as to eliminate said acceleration errors in a subsequent transport of the tape.

A method for controlling transportation of a tape between two reels in a tape transportation system comprising two motors for driving said reels, respectively and means for energizing said motors thereby effecting transportation of the tape, said method comprising the steps of:

• measuring an actual value of a given operation parameter of said tape transportation system during a transient period when the tape is mounted to the reels for transportation between them and its transportation speed is changed,
• calculating correction values of factors relating to driving currents of said reel driving motors, respectively, as energized by said tape transportation system, based on said measured actual value of said given operation parameter,
• storing said correction values to be used in a succeeding transportation of the tape, and
• correcting said factors based on said stored correction values, thereby correcting the driving currents of the respective reel motors in the succeeding transportation of the tape.

An apparatus for transporting a tape between two reels, comprising:

• reel motors for driving said reels, respectively,
• first means responsive to driving current commands applied thereto to supply driving currents corresponding to said commands, respectively, to said motors,
• second means for calculating said driving current commands based on a plurality of operating factors and applying said calculated current commands to said first means,
• third means for obtainng a value of at least one operating parameter representing condition of the transportation of the tape while the tape is mounted to said reels and the motors are energized for transportation of the tape between the reels,
• fourth means for correcting at least a part of said operating factors so as to reduce a deviation of the value of said operating parameter from a predetermined reference value thereof,
• fifth means for calculating said current commands based on said corrected operating factors and applying said corrected current commands to said first means in a succeeding transportation of the tape.

An apparatus for transporting a tape between two reels comprising:

• reel driving motors for driving the reels, respectively,
• first means for supplying driving currents to the motors, respectively,
• second means including tachometers connected to the reel motors, respectively, each of said tachometers generating pulses correspondingly to an amount of rotation of the associated motor, for calculating an amount of the tape wound on each of the reels based on the pulses generated by the associated tachometer,
• third means for detecting a value of a tension applied to the tape while the tape is mounted to the reels for transportation between the reels,
• fourth means for producing current commands for the respective driving currents to be supplied to said reel motors based on the amount of the tape wound on each of the reels as calculated by said second means, a desired value of the tension applied to the tape and a desired tape speed in its transportation between the reels and supplying said current commands to said first means,
• fifth means for determining a deviation of the tension value detected by said third means from the desired tension value while the reel motors are driven by driving currents supplied by said first means so that the tape is transported between the reels,
• sixth means for correcting said current commands produced by said fourth means based on said tension deviation so that said corrected current commands are supplied by said fourth means to said first means in a succeeding transportation of the tape.

An apparatus for transporting a tape between two reels comprising:

• reel driving motors for driving the reels, respectively,
• first means for supplying driving currents to the motors, respectively,
• second means for obtaining an amount of the tape wound on each of the reels,
• third means for detecting a value of a tension applied to the tape while the tape is mounted to the reels for transportation between the reels,
• fourth means for producing current commands for the respective driving currents to be supplied to said reel motors based on the amount of the tape wound on each of the reels as obtained by said second means, a desired value of the tension applied to the tape, a desired tape speed in its transportation between the reels and operating factors and for supplying said current commands to said first means,
• fifth means for determining a deviation of the tension value detected by said third means from the desired tension value while the reel motors are driven by driving currents supplied by said first means so that the tape is transported between the reels,
• sixth means for correcting at least one of said operating factors therby correcting said current commands produced by said fourth means so as to reduce said tension deviation so that said corrected current commands are supplied by said fourth means to said first means in a succeeding transportation of the tape.

An apparatus for transporting a tape between two reels comprising:

• a reel driving system including reel driving motors for driving the reels, respectively, and first means for supplying driving currents to said reel motors, respectively, based on current commands applied thereto,
• second means for determining said current commands by using a plurality of operating factors,
• third means for detecting a value of a tension applied to the tape while the tape is mounted to the reels and the reel motors are driven for transportation of the tape between the reels,
• fourth means for measuring a time interval at which the tape speed is changed from a first speed to a second speed, as the tape is transported between the reels,
• fifth means for determining whether there exists any error in operation of said reel driving system based on said detected tension value and said measured time interval and correcting, if it is determined that there exists any error in said reel driving system, at least one of said operating factors based on said detected tension value thereby correcting said current commands which are applied to said first means to said reel motors are corrected in the succeeding transportation of the tape so as to compensate for the error in said reel driving system.

A method for controlling transportation of a tape between two reels in a tape transportation system comprising two motors for driving said reels, respectively, and motor driving means for supplying driving currents to said motors for transportation of the tape between the reels, said method comprising:

• a first step of calculating current commands to be applied to said motor driving means for controlling said driving currents by using a plurality of operating factors,
• a second step of detecting a physical quantity representing a condition of the transportation of the tape, while the tape is mounted to the reels and the reel motors are driven for transportation of the tape between the reels,
• a third step of determining whether there exists any error in operation of said tape transportation system based on said detected physical quantity and correcting, if an existence of any error is determined, at least one of said operating factors thereby correcting said current commands so as to eliminate the error in operation of said reel driving system, and
• a fourth step of applying said corrected current commands to said motor driving means in a succeeding transportation of the tape between the reels.

A method for controlling transportation of a tape between two reels in a tape transportation system comprising two motors for driving said reels, respectively, and motor driving means for supplying driving currents to said motors for transportation of the tape between the reels, said method comprising:

• a first step of calculating an amount of the tape wound on each of the reels based on pulses produced correspondingly to the rotation of each of the motors,
• a second step of determining current commands indicative of said driving currents to be supplied to the respective motors based on said amount of the tape wound on each of said reels, a desired value of the tension and a desired speed in transportation of the tape,
• a third step of detecting a value of a tension applied to the tape, while the tape is mounted to the reels and the motors are driven by said driving currents for transportation of the tape between the reels,
• a fourth step of obtaining a deviation of the tension value detected by the second step from the desired value of the tension,
• a fifth step of determining an error in said tape transportation system depending on said tension deviation and calculating correction of said current commands which would be effective to cancel said error in said tape transportation system, and
• a sixth step of applying said corrected current commands to said motor driving means in a succeeding transportation of the tape between the reels.

A method for controlling transportation of a tape between two reels in a tape transportation system comprising two motors for driving said reels, respectively, and motor driving means for supplying driving currents to said motors for transportation of the tape between the reels, said method comprising:

• a first step of calculating current commands indicative of said driving currents to be supplied to said motors by using a plurality of operating factors,
• a second step of detecting a value of a tension applied to the tape, while the tape is mounted on the reels and the motors are driven for transportation of the tape between the reels,
• a third step of measuring a time interval required for the tape to change its speed from a first speed to a second speed, while the tape is mounted on the reels and the motors are driven for transportation of the tape between the reels,
• a fourth step of determining that there exists an error in said tape transportation system depending on said detected tension value and said measured time interval,
• a fifth step of correcting at least one of the operating factors so as to cancel the error in said tape transportation system based on said detected tension value and said measured time interval, and
• a sixth step of calculating new current commands by using the corrected operating factors and applying said new current commands to said motor driving means in a succeeding transportation of the tape between the reels so that said motors are driven by new driving currents represented by said new current commands.

A method for controlling transportation of a tape between two reels in a tape transportation system comprising two motors for driving said reels, for rotation, respectively, and motor driving means for supplying driving currents to said motors for transportation of the tape between the reels, said method comprising:

• a first step of determining an amount of the tape wound on each of the reels,
• a second step of calculating currents commands indicative of said driving currents to be supplied to the respective motors based on said amount of the tape wound on each of said reels, a desired value of the tension and a desired speed in transportation of the tape and a plurality of operating factors,
• a third step of detecting a value of a tension applied to the tape, while the tape is mounted to the reels and the motors are driven by said driving currents for transportation of the tape between the reels,
• a fourth step of determining an error in said tape transportation system depending on said detected tension value and correcting at least one of said operating factors so as to cancel said error in said tape transportation system, and
• a fifth step of repeating said first to fourth steps in a succeeding transportation of the tape between the reels, while substituting the operating factors with the corrected operating factors.