EP0177057A2 - Frankiermaschinenvorrichtung mit mikroprozessorgesteuertem Gleichstrommotor und Verfahren zu dessen Gebrauch - Google Patents

Frankiermaschinenvorrichtung mit mikroprozessorgesteuertem Gleichstrommotor und Verfahren zu dessen Gebrauch Download PDF

Info

Publication number
EP0177057A2
EP0177057A2 EP85112601A EP85112601A EP0177057A2 EP 0177057 A2 EP0177057 A2 EP 0177057A2 EP 85112601 A EP85112601 A EP 85112601A EP 85112601 A EP85112601 A EP 85112601A EP 0177057 A2 EP0177057 A2 EP 0177057A2
Authority
EP
European Patent Office
Prior art keywords
drum
motor
control signal
sheet
sensing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP85112601A
Other languages
English (en)
French (fr)
Other versions
EP0177057A3 (en
EP0177057B1 (de
Inventor
Edilberto I. Salazar
Wallace Kirschner
John L. Lorenzo
Keith E. Schubert
Philip Pollak, Jr.
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Pitney Bowes Inc
Original Assignee
Pitney Bowes Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=27097430&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP0177057(A2) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Priority claimed from US06/657,569 external-priority patent/US4631681A/en
Application filed by Pitney Bowes Inc filed Critical Pitney Bowes Inc
Publication of EP0177057A2 publication Critical patent/EP0177057A2/de
Publication of EP0177057A3 publication Critical patent/EP0177057A3/en
Application granted granted Critical
Publication of EP0177057B1 publication Critical patent/EP0177057B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07B—TICKET-ISSUING APPARATUS; FARE-REGISTERING APPARATUS; FRANKING APPARATUS
    • G07B17/00—Franking apparatus
    • G07B17/00459—Details relating to mailpieces in a franking system
    • G07B17/00661—Sensing or measuring mailpieces
    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07B—TICKET-ISSUING APPARATUS; FARE-REGISTERING APPARATUS; FRANKING APPARATUS
    • G07B17/00—Franking apparatus
    • G07B17/00459—Details relating to mailpieces in a franking system
    • G07B17/00467—Transporting mailpieces
    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07B—TICKET-ISSUING APPARATUS; FARE-REGISTERING APPARATUS; FRANKING APPARATUS
    • G07B17/00—Franking apparatus
    • G07B17/00459—Details relating to mailpieces in a franking system
    • G07B17/00508—Printing or attaching on mailpieces
    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07B—TICKET-ISSUING APPARATUS; FARE-REGISTERING APPARATUS; FRANKING APPARATUS
    • G07B17/00—Franking apparatus
    • G07B17/00185—Details internally of apparatus in a franking system, e.g. franking machine at customer or apparatus at post office
    • G07B17/00193—Constructional details of apparatus in a franking system
    • G07B2017/00266—Man-machine interface on the apparatus
    • G07B2017/00274—Mechanical, e.g. keyboard
    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07B—TICKET-ISSUING APPARATUS; FARE-REGISTERING APPARATUS; FRANKING APPARATUS
    • G07B17/00—Franking apparatus
    • G07B17/00459—Details relating to mailpieces in a franking system
    • G07B17/00508—Printing or attaching on mailpieces
    • G07B2017/00516—Details of printing apparatus
    • G07B2017/00524—Printheads
    • G07B2017/00548—Mechanical printhead
    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07B—TICKET-ISSUING APPARATUS; FARE-REGISTERING APPARATUS; FRANKING APPARATUS
    • G07B17/00—Franking apparatus
    • G07B17/00459—Details relating to mailpieces in a franking system
    • G07B17/00661—Sensing or measuring mailpieces
    • G07B2017/00669—Sensing the position of mailpieces
    • G—PHYSICS
    • G07—CHECKING-DEVICES
    • G07B—TICKET-ISSUING APPARATUS; FARE-REGISTERING APPARATUS; FRANKING APPARATUS
    • G07B17/00—Franking apparatus
    • G07B17/00459—Details relating to mailpieces in a franking system
    • G07B17/00661—Sensing or measuring mailpieces
    • G07B2017/00693—Measuring the speed of mailpieces inside apparatus

Definitions

  • the present invention is generally concerned with postage meters and mailing machines, and processes for operating such apparatus.
  • a postage meter which includes a drive mechanism connected by means of a drive train to a postage meter drum.
  • the drive mechanism includes a single revolution clutch for rotating the drum from a home position and into engagement with a letter fed to the drum.
  • the drum prints a postage value on the letter while feeding the same downstream beneath the drum as the drum returns to the home position.
  • Each revolution of the single revolution clutch and thus the drum is initiated by the letter engaging a trip lever to release the helical spring of the single revolution clutch.
  • the velocity versus time profile of the peripherary of a drum driven by the clutch approximates a trapezoidal configuration, having acceleration, constant velocity and deceleration portions, fixed by the particular clutch and drive train used in the application.
  • the throughput rate of any mailing machine associated with the meter is dictated by the cycling speed of the postage meter rather than by the speed with which the individual mailpieces are fed to the postage meter.
  • the single revolution clutch structure has served as to workhorse of the industry for many years it has long been recognized that it is a complex mechanism which is relatively expensive to construct and maintain, does not precisely follow the ideal trapezoidal velocity vs. time motion profile which is preferred for drum motion, tends to be unreliable in high volume applications, and is noisy and thus irritating to customers.
  • an object of the invention is to replace the postage meter drum drive mechanism of the prior art with the combination of a D.C. motor and a computer, and program the computer for causing the D.C. motor to drive the drum in accordance with an ideal trapezoidal-shaped velocity versus time profile which is a function of the input velocity of a mailpiece;
  • Another object is to replace the trip lever as the drive initiating device and utilize in its place a pair of spaced apart sensing devices in the path of travel of a mailpiece fed to the postage meter, and program the computer to calculate the input velocity of a mailpiece, based upon the time taken for the mailpiece to traverse the distance between the sensing devices, and adjust the time delay and acceleration of the drum before arrival of the mailpiece at a position at which drum rotation is commenced to cause the drum to timely engage the leading edge of the mailpiece.
  • an improvement comprising: first means for sensing a time interval during which a sheet is linearly displaced a predetermined distance in the path of travel; a d.c. motor coupled to the drum for rotation thereof; second means for sensing angular displacement of the drum; and computer means coupled to the first and second sensing means and to the d.c.
  • the computer means comprising: means responsive to the first sensing means for providing respective amounts representative of desired angular displacements of the drum during successive sampling time periods, means responsive to the second sensing means for providing respective amounts representative of actual angular displacements of the drum during successive sampling time periods, and means for compensating for the difference between desired and actual angular displacements and generating a d.c. motor control signal for controlling rotation of the motor to cause the linear displacement of the periphery of the drum to substantially match the linear displacement of the sheet during respective sampling time periods.
  • Figure 8 is a truth table showing the status of the transistors in the power amplifying circuit for clockwise and counter-clockwise rotation of the D.C. motor;
  • Figure 9 shows the relationship between the encoder output signals for various D.C. motor duty cycles
  • Figure 10 shows a closed-loop servo system including the D.C. motor and computer;
  • Figure 11 is a block diagram portraying the laplace transform equations of the closed-loop servo system shown in Fig. 10;
  • Figure 12 shows the equations for calculating the overall gain of the closed loop servo system of Fig. 10 before (Fig. 2a) and after (Fig. 2b) including a gain factor corresponding to the system friction at motor start up;
  • Figure 13 is a bode diagram including plots for the closed loop servo system before and after compensation to' provide for system stability and maximization of the system's bandwidth;
  • Figure 14 shows the equation for calculating, in the frequency domain, the value of the system compensator
  • Figure 15 shows the equation for calculating the damping factor, overshoot and settling time,of the servo controlled system
  • Figure 16 shows the equation for the laplace operator expressed in terms of the Z-transform operator
  • Figure 17 shows the equation for calculating the value of the system compensator in the position domain
  • Figure 18 shows the equations for converting the system compensator of Fig. 17 to the position domain
  • Figure 19 shows the equation of the output of the system compensator in the time domain
  • Figure 20 is a block diagram of a preferred microprocessor for use in controlling the D.C. Motor;
  • Figure 21 shows the time intervals during which the motor control signal and its separable components are calculated to permit early application of the signal to the motor;
  • Figure 22 (including Figs. 22a and 22b) is a block diagram of the computer according to the invention.
  • Figure 23 (including Figs. 23a-1, 23a-2, 23b and..23c) shows the flow charts portraying the processing steps of the computer.
  • the apparatus in which the invention may be incorporated generally includes an electronic postage meter 10 which is suitably removably mounted on a conventional mailing machine 12, so as to form therewith a slot 14 (Fig. 2) through which sheets, including mailpieces 16, such as envelopes, cards or other sheet-like materials, may be fed in a downstream path of travel 18.
  • the postage meter 10 (Fig. 1) includes a keyboard 30 and display 32.
  • the keyboard 30 includes a plurality of numeric keys, labeled 0-9 inclusive, a clear key, labeled "c” and a decimal point key, labeled ".”, for selecting postage values to be entered; a set postage key, labeled "s", for entering selected postage values; and an arithmetic function key, labeled " ", for adding subsequently selected charges (such as special delivery costs) to a previously selected postage value before entry of the total value.
  • a plurality of display keys, designated 34 each of which are provided with labels well known in the art for identifying information stored in the meter 10, and shown on the display 32 in response to depression of the particular key 34, such as the "postage used”, “postage unused”, “control sum”, "piece count”, “batch value” and “batch count” values.
  • the keys of the keyboard 30 and the display 32 and their respective functions may be found in U.S. Patent No. 4,283,721 issued August 11, 1981 to Eckert, et al. and assigned to the assignee of the present invention.
  • the meter 10 (Fig. 1) includes a casing 36, on which the keyboard 30 and display 32 are conventionally mounted, and which is-adapted by well known means for carrying a cyclically operable, rotary, postage printing drum 38.
  • the drum 38 (Fig. 2) is conventionally constructed and arranged for feeding the respective mailpieces 16 in the path of travel 18, which extends beneath the drum 38, and for printing entered postage on the upwardly disposed surface of each mailpiece 16.
  • the meter 10 (Fig. 1) also includes a conventional postage value selection mechanism 40, for example, of the type shown in U.S. Patent No. 4,287,825 issued September 8, 1981 to Eckert, et al. and assigned to the assignee of the present invention.
  • the mechanism 40 which is operably electrically coupled via the postage meter's computer 41 to the keyboard 30 and display 32, includes a first stepper motor 42 for selecting any one of a plurality of racks 43, associated on a one for one basis with each of the print wheels 44, and a second stepper motor 45 for actuating each selected rack 43 for positioning the appropriate printing element of the associated print wheel 44.
  • the rack selection stepper motor 42 which is referred to by skilled artisans as a bank selector motor, is appropriately energized via power lines 46 from the computer 41 for selecting the appropriate rack; and the rack actuating stepper motor 45, which is referred to by skilled artisans as a digit selector motor, is appropriately energized via power lines 47 from the computer 41 to move the selected rack for selecting the appropriate digit element of the associated print wheel 44.
  • a bank selector motor which is referred to by skilled artisans as a digit selector motor
  • the computer 41 for the postage meter 10 generally comprises a conventional, microcomputer system having a plurality of microcomputer modules including a control or keyboard and display module, 41a, an accounting module 41b and a printing module 41c.
  • the control ⁇ module 41a is both operably electrically connected to the accounting module 41b and adapted to be operably electrically connected to an external device via respective two-way serial communications channels
  • the accounting module 41b is ⁇ operably electrically connected to the printing module 41c via a corresponding two-way serial communication channel.
  • each of the modules 41a, 41b and 41c includes a dedicated microprocessor 41d, 41e or 41f, respectively, having a separately controlled clock and programs.
  • each of the modules 41a, 41b and 41c is capable of processing data independently and asynchronously of the other.
  • any command message from the control module 41a is communicated to the accounting module 41b, where it is processed either for local action in the accounting module 41b and/or as a command message for the printing module 41c.
  • any message from the printing module 41c is communicated to the accounting module 41b where it is either used as internal information or merged with additional data and communicated to the control module 41c.
  • any message from the accounting module 41b is initially directed to the printing module 41c or to the control module 41a.
  • the mailing machine 12 (Fig. 2), which has a casing 19, includes a A .C. power supply 20 which is adapted by means of a power line 22 to be connected to a local source of supply of A.C. power via a normally open main power switch 24 which may be closed by the operator. Upon such closure, the mailing machine's D .C. power supply 26 is energized via the power line 28.
  • the mailing machine 12 includes a conventional belt-type conveyor 49, driven by an A.C. motor 50, which is connected for energization from the A.C. power supply 20 via a conventional, normally open solid state, A.C. motor, relay 52, which is timely energized by a computer 500 for closing the relay 52.
  • A.C. power supply 20 which is adapted by means of a power line 22 to be connected to a local source of supply of A.C. power via a normally open main power switch 24 which may be closed by the operator.
  • the mailing machine's D .C. power supply 26 is energized via
  • the mailing machine preferably includes a keyboard 53 having a "start" key 53a and a “stop” key 53b, which are conventionally coupled to the main power switch 24 to permit the operator to selectively close and open the switch 24.
  • the A.C. motor 50 is energized from the A.C. power supply 20.
  • the conveyor 49 transports the individual mailpieces 16, at a velocity corresponding to the angular velocity of the motor 50, in the path of travel 18 to the postage printing platen 54.
  • the machine 12 includes first and second sensing devices respectively designated 56 and 58, which are spaced apart from each other a predetermined distance d 1 , i.e., the distance between points A and B in the path of travel 18.
  • each of the sensing devices 56 and 58 is an electro-optical device which is suitably electrically coupled to the computer 500; sensing device 56 being connected via communication line 60 and sensing device 58 being connected via communication line 62.
  • the sensing devices 56, 58 respectively respond to the arrival of a mailpiece 16 at points A and B by providing a signal to the computer 500 on communication line 60 from sensing device 56 and on communication line 62 from sensing device 58.
  • the rate of movement or velocity Vl of any mailpiece 16 may be calculated by counting the elapsed time t v (Fig. 3) between arrivals.of the mailpiece 16 at points A and B, and dividing the distance d l , by the elapsed time t v .
  • the velocity of the mailpiece may be expressed in terms of the total number Nt of time instants T n which elapse as the given mailpiece traverses the distance d l .
  • the time delay t d (Fig. 3) before arrival of the mailpiece 16 at point C may be calculated by dividing the distance d 2 between points B and C by the mailpiece's velocity Vl, provided the distance d 2 is known. Since the integral of the initial, triangularly-shaped, portion of the velocity versus time profile is equal to one-half of the value of the product of T a and V 1 , and is equal to the arc d 3 described by point E on the drum 38, as the drum 38 is rotated counter-clockwise to point D, the distance between points C and D is equal to twice the arcuate distance d 3 .
  • d 2 may be conventionally calculated, as may be the time delay t d for the maximum throughput velocity. Assuming rotation of the drum 38 is commenced at the end of the time delay t d and the drum 38 is linearly accelerated to the velocity Vl to match that of the mailpiece 16 in the time interval T a during which point E on the drum 38 arcuately traverses the distance d 3 to point D, Ta may be conventionally calculated.
  • the mailpiece 16 will arrive at point D coincident with the rotation of point E of the outer periphery 73 the drum 38 to point D, with the result that the leading edge 73a of the drum's outer periphery 73, which edge 73a extends transverse to the path of travel 18 of the mailpiece 16, will engage substantially the leading edge of the mailpiece 16 for feeding purposes and the indicia printing portion 73b of the periphery 73 will be marginally spaced from the leading edge of the mailpiece 16 by a distance d 4 which is equal to the circumferential distance between points E and F on the drum 38.
  • the time interval Tc during which the drum 38 is rotated at the constant velocity Vl may also be calculated.
  • the drum 38 commences deceleration and continues to decelerate to rest during the time interval Td.
  • the distance d 6 which is traversed by point G, as the drum 38 is rotated to return point E to its original position of being spaced a distance d 3 from point D, is fixed, and, Td may be chosen to provide a suitable deceleration rate for the drum,-preferably less than Ta.
  • a reasonable settling time interval Ts is preferably added to obtain the overall cycling time TcT of ; the drum 38 to allow for damping_any overshoot of the drum.38 before commencing the next drum cycle.
  • TcT 234 milliseconds
  • Td 24 milliseconds
  • target velocities VI which are less than the maximum throughput velocity
  • integral of, and thus the area under, the.velocity versus time profile remains constant, and equal to the area thereof at the maximum throughput velocity, to facilitate conventional calculation of the values of the time delay t d , the time intervals Ta, Tc and Td, and the acceleration and decceleration values for each of such lesser velocities Vl.
  • the computer 500 is programmed as hereinbefore discussed to continously poll the communication lines 60 and 62, from the sensing devices 56 and 58, respectively, each time interval T n , and count the time intervals T n between arrivals of the mailpiece 16 at points A and B as evidenced by a transition signals on lines 60 or 62.
  • the computer 500 is programmed to calculate the current velocity of the mailpiece 16 in terms of the total number N t of the counted time intervals T n , store the current velocity and, preferably, take an average of that velocity and at least the next previously calculated velocity (if any) to establish the target velocity V1._
  • precalculated values for the time delay td, acceleration and decceleration corresponding to each of a plurality of target velocities be stored in the memory of the computer 500 for fetching as needed after calculation of the particular target velocity.
  • the acceleration and decceleration values are each stored in the form of an amount corresponding to a predetermined number of counts per millisecond square which 4 are a function of the actual acceleration or decceleration value, as the case may be, and of the scale factor hereinafter discussed in connection with measuring the actual angular displacement of the motor drive shaft 122; whereby the computer 500 may timely calculate the desired angular displacement of the motor drive shaft 122 during any sampling time interval T.
  • the summation of all such counts is representative of the desired linear displacement of the circumference of the drum 38, and thus of the desired velocity versus time profile of drum rotation for timely accelerating the drum 38 to the target velocity Vl, maintaining the drum velocity at Vl for feeding the particular mailpiece 16 and timely deccelerati-ng the drum 38 to rest.
  • the postage meter 10 (Fig. 1) additionally includes a conventional, rotatably mounted, shaft 74 on which the drum 38 is fixedly mounted, and a conventional drive gear 76, which is fixedly attached to the shaft for rotation of the shaft 74.
  • the mailing machine 12 (Fig. 1) includes an idler shaft 80 which is conventionally journaled to the casing 19 for rotation, and, operably coupled to the shaft 80, a conventional home position encoder 82.
  • the encoder 82 includes a conventional circularly-shaped disc 84, which is fixedly attached to the shaft 80 for rotation therewith, and an optical sensing device 86, which is operably coupled to the disc 84 for detecting an opening 88 formed therein and, upon such detection., signalling the computer 500.
  • the machine 12 also includes an idler gear 90 which is fixedly attached to the shaft 80 for rotation therewith.
  • the machine 12 includes a D.C. motor 120, which is suitably attached to the casing 19 and has a drive shaft 122.
  • the machine 12 also includes a pinion gear 124, which is fixedly attached to the drive shaft 122 for rotation by the shaft 122.
  • the gear 124 is disposed in driving engagement with the idler gear 90. Accordingly, rotation of the motor drive shaft 122 in a given direction, results in the same direction of rotation of the drum drive shaft 76 and thus the drum 38.
  • the pinion gear 124 has one-fifth the number of teeth as the drum drive gear 76, whereas the idler gear 90 and drum drive gear 76 each have the same number of teeth. With this arrangement, five complete revolutions of the motor drive shaft 122 effectuate one complete revolution of the drum 38, whereas each revolution of the gear 90 results in one revolution of the gear 76.
  • the encoder disc 84 may be mounted on the idler shaft 90 such that the disc's opening 88 is aligned with the sensing device 86 when the drum 38 is disposed in its home position to provide for detection of the home position of the drum shaft 74, and thus a position of the drum shaft 74 from which incremental angular displacements may be counted.
  • a quadrature encoder 126 (Fig. 1).
  • the encoder 126 is preferably coupled to the motor drive shaft 122, rather than to the drum shaft 74, for providing higher mechanical stiffness between the armature of the d.c. motor 120 and the encoder 126 to avoid torsional resonance effects in the system.
  • the encoder 126 includes a circularly-shaped disc 128, which is fixedly attached to the motor drive shaft.122 for operably connecting the encoder 126 to the motor 120.
  • the disc 128 (Fig.
  • the disc 128 which is otherwise transparent to light, has a plurality of opague lines 130 which are formed on the disc 128 at predetermined, equidistantly angularly- spaced, intervals along at least one of the dics's opposed major surfaces.
  • the disc 128 includes one'hundred and ninety-two lines 130 separated by a like number of transparent spaces 132.
  • the encoder 126 includes an optical sensing device 134, which is conventionally attached to the casing 19 and disposed in , operating relationship with respect to the disc 128, for serially detecting the presence of the respective opaque lines 130 as they successively pass two reference positions, for example, positions 136ra and 136rb, and for responding to such detection by providing two output signals, one on each of communications lines 136a and 136b, such as signal A (Fig. 5) on line 136a and signal B on line 136b. Since the disc 128 (Fig. 4) includes 192 lines 130 and the gear ratio of the 4 drum drive gear 76 (Fig. 1) to the motor pinion gear 124 is five-to-one, nine hundred and sixty signals A and B (Fig.
  • each of the communications lines 136a and 136b are provided on each of the communications lines 136a and 136b during five revolutions of the motor-drive shaft 122, and thus, during each cycle of rotation of the drum 38. Since the angular distance between successive lines 130 (Fig. 4) is a constant, the time interval between successive leading edges (Fig. 5) of each signal A and B is inversely proportional to the actual velocity of rotation of the motor drive shaft (Fig. 1) and thus of the drum 38.
  • the encoder 126 is conventionally constructed and arranged such that the respective reference positions 136a and 136b (Fig. 4) are located with respect to the spacing between line 130 to provide signals A and B (Fig. 5) which are 90 electrical degrees out of phase. Accordingly, if signal A lags signal B by 90° (Fig.
  • the quadrature encoder communication lines, 136a and 136b may be connected either directly to the computer 500 for pulse counting thereby or to the computer 500 via a conventional counting circuit" 270 (Fig. 6), depending on whether or not the internal counting circuitry of the computer 500 is or is not available for such counting purposes in consideration of other design demands of the system in which the computer 500 is being used.
  • a counting circuit 270 Assuming connection to the computer 500 via., a counting circuit 270, the aforesaid communications lines, 136a and 136b are preferably connected via terminals A and B, to the counting circuit 270.
  • the counting circuit 270 utilizes the pulses A (Fig.-5) to generate a clock signal and apply the same to a conventional binary counter 274 (Fig. 6), and to generate an up or down count depending on the lagging or leading relationship of pulse A (Fig. 5) relative to pulse B and apply the up or down count to the binary counter 274 (Fig. 6) for counting thereby.
  • the pulses A and B (Fig. 5) which are applied to the counting circuit terminals A and B (Fig. 6) are respectively fed to Schmidt trigger inverters 276A and 276B.
  • the output from the inverter 276A is fed directly to one input of an XOR gate 278' and additionally via an R -C delay circuit 280 and an inverter 282 to the other input of the XOR gate 278.
  • the output pulses from the XOR gate 278, which acts as a pulse frequency doubler, is fed to a conventional one-shot multivibrator 284 which detects the trailing edge of each pulse from the XOR gate 278 and outputs a clock pulse to the clock input CK of the binary counter 274 for each detected trailing edge.
  • the output from the Schmidt trigger inverters 276A and 276B are respectively fed to a second XOR gate 286 which outputs a low logic level signal (zero), or up-count, to the up-down pins U/D of the binary counter 274 for each output pulse A (Fig. 5) which lags an output pulses B by 90 electrical degrees.
  • the XOR gate 286 (Fig. 6) outputs a high logic level (one) or down-count, to the up-down input pins of the binary counter 274 for each encoder output pulse A (Fig. 5) which leads an output pulse B by 90° electrical degrees. Accordingly, the XOR gate 286 (Fig.
  • the binary counter 274 (Fig. 6) counts the up and down count signals from the XOR gate 286 whenever any clock signal is received from the multivibrator 284, and updates the binary output signal 272 to reflect the count.
  • the counting circuit 270 converts the digital signals A and B, which are representative of incremental angular displacements of the drive shaft 122 in either direction of rotation thereof,- to an eight bit wide digital logic output signal 272 which corresponds to a summation count at any given time, of such displacements, multiplied by a factor of two, for use by the computer 500. Since the angular displacement of the shaft 122 from its home position is proportional to the angular displacement of the drum 38 from its home position, the output signal 272 is a count which is proportional to the actual linear displacement of the outermost periphery of the drum 38 at the end of a given time period of rotation of the drum 38 from its home position.
  • any other target velocity Vl, or any acceleration or decceleration value may be , expressed in terms of counts per sampling time interval T, or counts per square millisecond, as the case may be, by utilization of the aforesaid scale factor.
  • a power amplifying circuit 300:- The power amplifying circuit 300 (Fig. 7) is conventionally operably connected to the motor terminals 302 and 304 via power lines 306 and 308 respectively.
  • the power amplifying circuit 300 preferably comprises a conventional, H-type, push-pull, control signal amplifier 301 having input leads A, B, C and D, a plurality of optical-electrical isolator circuits 303 which are connected on a one-for-one basis between the leads A-D and four output terminals of the computer 500 for coupling the control signals from the computer 500 to the input leads A, B, C, and D of the amplifier 301, and a plurality of conventional pull-up resistors 305 for coupling the respective leads A-D to the 5 volt source.
  • the amplifier 301 includes four conventional darlington-type, pre-amplifier drive circuits including NPN transistors Tl, T2, T3 and T4, and four, conventional, darlington-type power amplifier circuits including PN P transistors Ql, Q2, Q3 andQ4 which are respectively coupled on a one-for-one basis to the collectors of transistors Tl, T2, T3 and T4 for driving thereby.
  • the optical-electrical isolator circuits 303 each include a light emitting diode Dl and a photo-responsive transistor T5.
  • the cathodes of Dl are each connected to the 5 volt source, the emitters of T5 are each connected to ground and the collectors of T5 are each coupled, ' on a -one-for-one basis, to the base of one of the transistors Tl, T2, T3 and T4.
  • the opto-isolator circuits 303 when a low logic level signal is applied to the anode of Dl, Dl conducts and illuminates the base of T5 thereby driving T5 into its conductive state; whereas when a high logic level signal is applied to the anode of Dl, Dl is non-conductive, as a result of which T5 is in its non-conductive state.
  • the base of transistor Ql, Q2, Q3 or Q4, as the case may be, is clamped to ground via the emitter-collector circuit of its associated driver transistor Tl, T2, T3 or T4, thereby driving the transistor Ql, Q2, Q3 or Q4, as the case may be, into its conductive state.
  • the transistor pairs Tl and Ql, T2 and Q2, T3 and Q3, and T4 and Q4 are respectively biased to cut-off when lead A, B, C or D, as the case may be, is connected to ground via the collector-emitter circuit of the associated opto-isolator circuit's transistor T5. As shown in the truth table (Fig.
  • terminal 304 of the motor 120 is connected to ground via the emitter-collector circuit of Q4, which occurs when Q3 is turned off and the .base of Q4 is grounded through the emitter-collector circuit of T4_due to the base of T4 drawing current from the 5 volt.source in the presence of a high logic level signal at the input terminal D.
  • terminal 302 of the motor 120 is connected to ground via the emitter-collector circuit of Q2, which occurs when Ql is turned off and the base of Q2 is grounded through the emitter-collector circuit of T2 due to the base of T2 drawing current from the 5 volt source in the presence of a high logic level control signal at the input terminal B; and terminal 304 of the motor 120 is connected to the 30 volt source via the emitter-collector circuit of Q3, which occurs when Q4 is turned off and the base of Q3 is grounded through the emitter-collector of T3 due to the base of T3 drawing current from the 5 volt source in the presence of a high logic level control signal at the input terminal C.
  • low level control signals are applied on a selective basis to the two terminals B and C, or A and D, as the case may be, to which high logic control level signals are not being applied; which occurs when the opto-isolator circuit's transistors T5 associated with the respective leads B and C or A and D are driven to their conductive states,
  • the bases of the transistors T2 and T3, or Tl and T4 as the case may be, are biased to open the emitter- collectors circuits of the transistors T2 and T3, or Tl and T4, as the case may be, as a result of which the bases of the transistors Q2 and Q3, or Ql and Q4, as the case may be, are biased to open the emitter-collector circuits of transistors Q2 and Q3, or Ql and Q4, as the case may_be.
  • the velocity of the motor 120 (Fig. 7) is controlled by modulating the pulse width and thus the duty cycle of the high logic level, constant frequency, control signals, i.e., pulse width modulated (PWM) signals, which are timely applied on a selective basis to two of the leads A-D, while applying the low level logic signals to those of leads A-D which are not selected.
  • PWM pulse width modulated
  • the motor 120 may be dynamically braked by temporarily applying high level PWM signals having a selected duty cycle corresponding to a given positive average value to leads B and C, in combination with low logic signals-being applied to leads A and D.
  • the emitter-collector circuits of the power transistors Ql, Q2, Q3 and Q4 are respectively shunted to the 30 volt source by appropriately poled diodes, Dl, D2, D3 and D4 connected across the emitter-collector circuits of Ql, Q2, Q3 and Q4.
  • the D.C. motor 120 and its shaft encoder 126 are respectively connected to the computer 500 via the power amplifier circuit 300 and the counting circuit 270.
  • the computer 500 is programmed to calculate the duration of and timely apply PWM control signals to the power amplifier circuit 300 after each sampling time instant Tn, utilizing an algorithm based upon a digital compensator D(s) derived from analysis of the motor 120, motor load 38, 74, 76, 90 and 124 amplifying circuit 300, encoder 126, counting circuit 270, and the digital compensator D(s) in the closed-loop, sampled-data, servo-control system shown in Fig. 10.
  • a summation is taken of the aforesaid actual count and the previously calculated count representing the desired position of the motor drive shaft 122, and thus the drum 38, at the end of the time period T, and, under control of the computer program .implementation of the algorithm, a PWM control signal which is a function of the summation of the respective counts, or error, is applied to the power amplifier circuit 301 for rotating the motor drive shaft 122 such that the error tends to become zero at the end of the next sampling time period T.
  • the servo-controlled system of Fig. 10 is preferably analyzed in consideration of its equivalent Laplace transformation equations shown in Fig. 11, which are expressed in terms of the following Table of Parameters and Table of Assumptions.
  • D(S) is the unknown transfer function of an open loop compensator in the frequency domain. Due to a key factor for providing acceptably fast motor response being the system's resonance between the motor and load, the derivation of the transfer function D(S) for stabilization of the system is preferably considered with a view to maximizing the range of frequencies within which the system will be responsive, i.e., maximizing the system's bandwidth, BW.
  • Other sampling periods and other conventional microprocessors may be utilized without departing from the spirit and scope of the invention.
  • the open loop system gain H 1 (S) without compensation, of the servo-loop system of Fig. 10 is shown in Fig: 12(a).
  • H 1 (S) The open loop system gain H 1 (S) without compensation, of the servo-loop system of Fig. 10 is shown in Fig: 12(a).
  • the gain equation of Fig. 12(a) was adjusted to provide a corrective torque C t with a motor shaft movement, in radians per count, equivalent to the inverse expressed in radians per count, of the gain Kp of the encoder counting circuit transform.
  • K c K o
  • K o K o
  • K o may not be the overall system gain which is needed for system compensation for maximizing the system bandwidth BW, as a result of which it is premature to conclude that K c will be equivalent to the D.C. gain of the system compensator D(S).
  • the bode diagram shown in Fig. 13 may be constructed due to having calculated a minimum value for K o .
  • the absolute value of H 2 (S) in decibels, has been plotted against the frequency W in radians per second, based on the calculated minimum value of K o , the selected value of T and calculated values of the poles f l and f 2 .
  • a numerical value of the cross-over frequency W cl of the Bode plot of H 2 (S) may be determined, i.e., W Cl was found to be substantially 135 radians per second.
  • phase margin value which was much, much, less (i.e., 5°) than 45°, which, for the purposes of the calculations was taken to be a minimum desirable value for the phase margin ⁇ m in a position- type servo.system. Accordingly, it was found that the uncompensated system H 2 (S) was unstable if not compensated. Since an increase in phase lead results in an increase in bandwidth BW, and the design criteria calls for maximizing the bandwidth BW and increasing the phase margin to at least 45°; phase lead compensation was utilized.
  • a phase lead compensator D(S) has the Laplace transform shown in Fig. 14, wherein K c is the phase lead D.C. gain, and f z and fp are respectively a zero pole frequency and a phase lead pole frequency.
  • K c is the phase lead D.C. gain
  • f z and fp are respectively a zero pole frequency and a phase lead pole frequency.
  • the cross-over frequency W c2 for the compensated system H 3 (S) may be read from the Bode diagram, i.e., W c2 was found to be substantially equal to 400 radians per second.
  • the pole frequency fp lies at the geometric means of fp and W c2
  • ⁇ mc 180°-90°-tan -1 (w c2 /f 2 )-tan -1 (W c2 T/2).
  • the value of W c2 for the compensated system H 3 (S) was found to be substantially three times that of the uncompensated system H 2 (S), as a result of which the bandwidth BW of the system H(S) was increased by a factor of substantially three to BW c .
  • the relevant values may be calculated or estimated, as the case may be, from the expressions, for d f , o s , t x and t s shown in Fig. 15.
  • the foregoing analysis is based on controlling a postage meter drum, which has a high moment of inertia, contributes high system fric:tion, and calls for a cyclical start-stop mode of operation during which the load follows a predetermined displacement versus time trajectory to accommodate the maximum mailpiece transport speed in a typical mailing machine.
  • the Bode plot of the compensator D (S), Fig. 14, may be added to the Bode diagram (Fig. 13) wherein the system compensator D(S) is shown as a dashed line.
  • the analog compensator D(S) was derived in the frequency domain, D(S) was converted to its Z-transform equivalent D(Z) in the sampled data domain for realization in the form of a numerical algorithm for implementation by a computer.
  • the bi-linear transformation may be chosen.
  • Fig. 19 which defines the output G(T n ) in the time domain of the system compensator D(S), and is a numerical expression of the algorithm to be implemented by the computer for system compensation purposes.
  • the output of the digital compensator for any current sampling instant T n is a function ; of the position error at the then current sampling time instant T n , is a function of the position error at the end of the next previous sampling time instant T n - 1 and is a function of the algorithm output at the end of the next previous sampling time instant T n-1 .
  • the algorithm which is to be implemented by the computer 500 for system compensation purposes is a function of a plurality of historical increments of sampled data for computing an input value for controlling a load to follow a predetermined position trajectory in a closed loop sampled-data servo-control system.
  • the computer 500 preferably includes a conventional, inexpensively commercially available, high speed microprocessor 502, such as the Model 8051 single chip microprocessor commercially available from Intel Corporation, 3065 Bowers Avenue, Santa Clara, California 95051.
  • the microprocessor 502 generally comprises a plurality of discrete circuits, including those of a control processor unit or CPU 504, an oscillator and clock 506, a program memory 508, a data memory 510, timer and event counters 512, programmable serial ports 514, programmable I/O ports 516 and control circuits 518, which are respectively constructed and arranged by well known means for executing instructions from the program memory 508 that pertain to internal data, data from the clock 506, data memory 510, timer and event counter 512, serial ports 514, I/0 ports 514 interrupts 520 and/or bus 522 and providing appropriate outputs from the clock 506, serial ports 514, I/O ports 516 and timer 512.
  • Model 8051 microprocessor including optional methods of programming port 3 for use as a conventional bidirectional port, may be found in the Intel Corporation publication entitled MCS-51 Family of Single Chip Microcomputers Users Manual, dated January 1981.
  • one of the microprocessor's timer and event counters 512 (Fig. 20) is conventionally programmed as a sampling time period clock source.
  • a calculation may be made of the desired angular displacement of the motor drive shaft for the next subsequent time period T.
  • the microprocessor is programmed for implementation of the aforesaid calculation process to facilitate early utilization of the compensation algorithm output value G(T n ) for driving the D.C. motor.
  • the microprocessor is programmed for immediately after calculating the then current compensation algorithm output value GCT n ), and thus while the calculation of the value of g 2 for the next sampling time period is in progress, generating a motor control signal for energizing the power amplifier.
  • the relative voltage levels of motor control signal are determined by the sign, i.e., plus or minus, of the compensation algorithm output value G(T n ), and the duty cycle of the control signal is determined by the absolute value of the compensation algorithm output value G(T n ).
  • the other timer and event counter 512 i.e., the timer 512 which was not used as a sampling time period clock source, is utilized for timing the duration of the duty cycle of the motor control signal.
  • the timer 512 which was not used as a sampling time period clock source.
  • the time delay T d y from commencement of the time period T to updating the PWM motor control signal at the output ports of the microprocessor is substantially 55 microseconds, and the time interval allocated for calculating the value of g2 and the count representative of the desired angular displacement of the motor drive shaft for use during the next time period is substantially 352 microseconds.
  • the computer 500 is preferably modularly constructed for segregating the components of the logic circuit 501a and analog circuit 501b of the computer 500 from each other.
  • the respective circuits 501a and 50lb may be mounted on separate printed circuit boards which are electrically isolated from each other and adapted .to be interconnected by means of connectors located along the respective dot-dash lines 516, 527 and 528.
  • the components of the logic circuit 521a and analog circuit 521b are preferably electrically isolated from each other.
  • the logic circuit 501a preferably includes 5V and ground leads from the mailing machine's power supply for providing the logic circuit 501a with a local 5 volt source 530 having 5V and GND leads shunted by filter capacitors Cl and C2.
  • the analog circuit 501b includes 30 volt and ground return leads from the mailing machine's power supply for providing the analog circuit 501b with a local 30 volt source 536 including 30V and GND leads shunted by filter capacitors C3 and C4.
  • the analog circuit 501b includes a conventional'30 volt detection circuit 542 having its input conventionally connected to the analog circuit's 30 volt source 536, and its output coupled to a power up/down lead from the analog circuit via a conventional optical-electrical isolator circuit 544.
  • the analog circuit 501b is equipt with a conventional regulated power supply having its input appropriately connected to the analog circuit's 30 volt source 536 via a series connected resistor Rl and a 5 volt, voltage regulator 548.
  • a zener diode Dl having its cathode shunted to ground and having its anode connected to the input of the 5V regulator 548 and also connected via the resistor Rl to the 30 volt terminal line, is provided for maintaining the input to the 5V regulator 548 at substantially a 5 volt level.
  • a pair of capacitors C5 and C6 are provided across the output of the regulator 548 for filtration purposes.
  • any two available ports of the computer 41 may be programmed for two-way'serial communications purposes and coupled to the-computer 500.
  • the postage meter's printing module 41a may be conventionally modified to include an additional two-way serial communications channel for communication with the computer 500..
  • serial input communications to the computer 500 are received from the postage meter computer's printing module 41c via the serial input lead to the logic circuit 501a (Fig. 22), which is operably coupled to port P3 0 of the microprocessor 502 by means of a conventional inverting buffer circuit 550.
  • port P3 0 is preferably programmed for serial input communications, and the input to the buffer circuit 550 is resistively coupled to the logic circuit's 5 volt source 530 via a conventional pull-up resistor R 2.
  • Serial output communications from the microprocessor 502 are transmitted from port P3 1 .
  • port P3 1 is-preferably programmed for serial output communications, and is operably coupled to the input of a conventional inverting buffer 552, the output of which is resistively coupled to the logic circuit's 5V source 530 via a suitable pull-up resistor R2 and is additionally electrically connected to the serial output lead from the logic circuit 501a.
  • the logic circuit's 5V source 530 is connected in series with an R-C delay circuit and a conventional inverting buffer circuit 554 to the reset pin, RST, of the microprocessor 502.
  • RST reset pin
  • the logic circuit's 5V source 530 is connected in series with an R-C delay circuit and a conventional inverting buffer circuit 554 to the reset pin, RST, of the microprocessor 502.
  • R-C circuit includes a suitable resistor R3 which is connected in series with the logic circuit's local 5V source 530 and a suitable capacitor C7 which has one end connected between the resistor R3 and the input to the buffer circuit 554, and the other end connected to the logic circuit's ground return.
  • the E A terminal is connected to the logic circuit's 5V source.
  • the E A terminal is connected to the logic circuit's 5V source.
  • no other external memory is position lead of the logic circuit, which, in turn, is connected to one input of a differential amplifier 562, the output of which is connected to the other input of the differential amplifier 562 via a feedback resistor R4.
  • the aforesaid other input to the amplifier 562 is also resistively coupled, by means of a resistor R5, to the mid-point of a voltage divider circuit including resistors R6 and R7.
  • Resistors R6 and R7 are connected in series with each other and across the logic circuit's 5V source and ground return leads.
  • the LED sensors 56 and 58 which are utilized for successively sensing the leading edges of each envelope being fed by the letter transport, are separately coupled to the computer 500 via the envelope sensor-1 and envelope sensor-2 input leads of the logic circuit 501a.
  • the envelope sensor-1 and sensor-2 leads are connected on a one-for-one basis to one of the inputs of a pair of conventional amplifiers 564, the other inputs of which are connected together and to the mid-point of a voltage divider including resistors R8 and R9.
  • Resistors R8 and R9 are connected in series with each other and across the logic circuit's 5V source and ground return leads.
  • the three output signals from the differential amplifier 562 and the two amplifiers 564 are connected on a one-for-one basis to the three input ports PO O - 2 of the microprocessor 502, each via a conventional tri-state buffer circuit 566, one of which is shown.
  • the input signals A and B from the D.C. motor shaft encoder 126 are coupled to the logic circuit 501a position lead of the logic circuit, which, in turn, is connected to one input of a differential amplifier 562, the output of which is connected to the other input of the differential amplifier 562 via a feedback resistor R4.
  • the aforesaid other input to the amplifier 562 is also resistively coupled, by means of a resistor R5, to the mid-point of a voltage divider circuit including resistors R6 and R7.
  • Resistors R6 and R7 are connected in series with each other and across the logic circuit's 5V source and ground return leads.
  • the LED sensors 56 and 58 which are utilized for successively sensing the leading edges of each envelope being fed by the letter transport, are separately coupled to the computer 500 via the envelope sensor-1 and envelope sensor-2 ' input leads of the logic circuit 501a.
  • the envelope sensor-1 and sensor-2 leads are connected on a one-for-one basis to one of the inputs of a pair of conventional amplifiers 564, the other inputs of which are connected together and to the mid-point of a voltage divider including resistors R8 and R9.
  • Resistors R8 and R9 are connected in series with each other and across the logic circuit's 5V source and ground return leads.
  • the three output signals from the differential amplifier 562 and the two amplifiers 564 are connected on a one-for-one basis to the three input ports PO O-2 of the microprocessor 502, each via a conventional tri-state buffer circuit 566, one of which is shown.
  • the input signals A and B from the D.C. motor shaft encoder 126 are coupled to the logic circuit 501a by means of leads A and B, which are conventially electrically connected to the counting circuit 270 to provide the microprocessor 502 the the count representative of the actual angular displacement of the motor shaft 122 from its home position.
  • the counting circuit's leads QO-Q7 are electrically connected on a one-for-one basis to Ports PO ⁇ -PO 7 of the microcomputer 502 via one of eight conventional tri-state buffer-circuits 568, one of which is shown, having their respective control input leads connected to each other and to the output of a conventional inverting buffer circuit 570, which has its input conventionally connected port P3 4 of the microprocessor 502.
  • either the three input signals, i.e., from the drum home position and the two envelope position sensors are operably electrically coupled to Ports PO O -P0 2 of the microprocessor 502, or the eight input signals QO-Q7 from the counter circuit 270 are operably electrically coupled to ports P0 0 -P0 7 of the microprocessor 502, for scanning purposes, in response to an appropriate control signal being applied to the respective buffer circuits 566 and 568 from port P3 4 of the microprocessor 502.
  • port P3 5 is connected to the clear pin CLR of the counter 270 via a conventional inverting buffer 572, and the microprocessor 502 is programmed for timely applying the appropriate signal to port P3 5 which, when inverted, causes the counting circuit 270 to be cleared.
  • ports Pl 0 -Pl 3 are utilized by the microprocessor 502 for providing pulse width modulated (PWM) motor control signals for controlling energization of the D.C. motor 120 and port P1 4 is utilized by the microprocessor 502 for controlling energization of the solid state, A.C. motor, relay 52 and thus operation of the mailpiece conveyor 49.
  • ports Pl 0 -Pl 4 of the microprocessor 502 are each conventionally electrically connected on a one-for-one basis to the input of a conventional inverting buffer circuit 580, one of which is shown.
  • each of the buffer circuits 580 are connected on a one-for-one basis, via a conventional resistor R10, to output leads from the logic circuit 501b, one of which is designated solid state, A.C. motor, relay, and four of which are respectively designated Tl, T3, T2 and T4, since, as shown in Fig. 7, the four preamplifier stages of the power amplifier utilized for opto-isolator's photo-transistor when the light emitting diode Dl is lit in response to the D.C. supply voltage level matching the internal reference voltage level, e.g., 30 volts, of the 30 volt detection circuit.
  • each of the outputs from the photo-transistors of each of the opto-isolators 303 are resistively coupled to the analog circuits 5V source by means of a conventional pull-up resistor 305, and the emitters of the photo-transistors T5 are connected to the analog circuit's ground system.
  • the collectors of the photodiodes of the opto-isolators 303 which are utilized for transmitting the motor control signals from ports Pl 0 -Pl 3 of the microprocessor 502 are connected on a one-for-one basis to the appropriate input leads A, B, C and D of the power amplifiers shown in Fig. 7, the outputs of which are connected to the D.C. motor 120.
  • the collector of the photodiode of the opto-isolator 303 which is utilized for transmitting the A.C. relay control signals from port P1 4 of the microprocessor 502 is connected to the input lead of a conventional darlington-type power amplifier 550, the output of which is conventionally connected to the mailing machine's 30 volt D.C. source via a solid state, A.C. motor, relay 52, which is turn conventionally connected for energizing the A.C. motor 50 from the local A.C. source.
  • the computer 500 includes three software programs, including a main line program Fig. 23, a transmit and receive program'and a command execution program, respectively identified by the 600, 700 and 800 series of opto-isolator's photo-transistor when the light emitting diode Dl is lit in response to the D.C. supply voltage level matching the internal reference voltage level, e.g., 30 volts, of the 30 volt detection circuit.
  • a main line program Fig. 23 a transmit and receive program'and a command execution program, respectively identified by the 600, 700 and 800 series of opto-isolator's photo-transistor when the light emitting diode Dl is lit in response to the D.C. supply voltage level matching the internal reference voltage level, e.g., 30 volts, of the 30 volt detection circuit.
  • each of the outputs from the photo-transistors of each of the opto-isolators 303 are resistively coupled to the analog circuits 5V source by means of a conventional pull-up resistor 305, and the emitters of the photo-transistors T5 are connected to the analog. circuit's ground system.
  • the collectors of the photodiodes of the opto-isolators 303 which are utilized for transmitting the motor control signals from ports Pl 0 -Pl 3 of the microprocessor 502 are connected on a one-for-one basis to the.appropriate input leads A, B, C and D of the power amplifiers shown in Fig. 7, the outputs of which are connected to the D.C. motor 120.
  • the collector of the photodiode of the opto-isolator 303 which is utilized for transmitting the A.C. relay control signals from port P1 4 of the microprocessor 502 is connected to the input lead of a conventional darlington-type power amplifier 550, the output of which is conventionally connected to the mailing machine's 30 volt D.C. source via a solid state, A.C. motor, relay 52, which is turn conventionally connected for energizing the A.C. motor 50 from the local A.C. source.
  • the computer 500 includes three software programs, including a main line program Fig. 23, a transmit and receive program and a command execution program, respectively identified by the 600, 700 and 800 series of numbers.
  • a main line program Fig. 23 When the mailing machine 10 is energized by actuation of the main power switch 24, the resulting low level logic signal from D.C. supply is applied to the reset terminal RST of the computer's microprocessor 502, thereby enabling the microprocessor 502.
  • the microprocessor 502 commences execution of the main line program 600.
  • the main line program 600 commences with the step of conventionally initializing the microprocessor 602, which generally includes establishing the initial voltage levels at the microprocessor's ports, and interrupts, and setting the timers and counters. Thereafter, the D.C. motor drive unit is initialized 604. Step 604 entails scanning the motor home position sensor input port PO O , to determine whether or not the D.C. motor 120 is located in its home position and, if it is not, driving the motor 120 to its home position. Assuming the D.C. motor 120 is in its home position, either before or after the initialization step 604, the program then enters an idle loop routine 606.
  • Step 610 includes the successive steps 610a and 610b, respectively, of sampling the count of the actual position Pa of the motor drive shaft 122 at the sampling time instant T n , and fetching the previously cpmputed count representing the desired position Pd of the shaft 122 at the same sampling time instant T n . If for any reason the motor drive shaft 122 is not located in its home position when the value of the desired position count Pd(T n ) is representative of the home position location, then the values of Pa(T n ) and Pd(T n ) will be different.
  • the microprocessor 502 commences polling the ports connected to the envelope sensors 56 and 58, step 614. Since polling occurs at one millisecond time intervals; the polling sequence is continuous. As shown by the following step 616, between successive time instants T n , the program continuously loops to idle 606 and through steps 608-616 inclusive until the envelope sensing sequence for a given envelope is complete.
  • step 618 which includes the steps of calculating the envelope's velocity, 618a; then fetching from memory the corresponding acceleration, deceleration and constant velocity constants, 618b, for computation of the desired position counts Pd at each successive time instant T n in advance of sampling the actual position counts Pa as hereinbefore discussed in connection with step 610; then fetching and implementing the time delay t d for timely commencing acceleration of the drum 38 to the target velocity VI; and then commencing drum rotation by generating the desired position P d for the initial one millisecond sampling time instant of acceleration of the motor drive shaft 122 and storing the value for subsequent use in step 601b. Accordingly, the value of Pd shaft 122 out of the home position, until a mailpiece 16 is fed to the drum 38.
  • the microprocessor 502 commences polling the ports connected to the envelope sensors 56 and 58, step 614. Since polling occurs at one millisecond time intervals, the polling sequence is continuous. As shown by the following step 616, between successive time instants T n , the program continuously loops to idle 606 and through steps 608-616 inclusive until the envelope sensing sequence for a given envelope is complete.
  • step 618 which includes the steps of calculating the envelope's velocity, 618a; then fetching from memory the corresponding acceleration, deceleration and constant velocity constants, 618b, for computation of the desired position counts Pd at each successive time instant Tn in advance of sampling the actual position counts Pa as hereinbefore discussed in connection with step 610; then fetching and implementing the time delay t d for timely commencing acceleration of the drum 38 to the target velocity Vl; and then commencing drum rotation by generating the desired position P d for the initial one millisecond sampling time instant of acceleration of the motor drive shaft 122 and storing the value for subsequent use in step 601b. Accordingly, the value of Pd will no longer be assumed to be the value representative of the home position.
  • step 620 the inquiry is made as to whether or not the drum cycle is complete, step 620. Assuming as stated above that only the initial desired value of Pd has been computed and stored, the inquiry of step 620 will be answered in the negative. Whereupon the microprocessor 502 transmits a status message, step 622, to the postage meter's computer 41 and the program loops to idle 606. Thereafter the microprocessor 502 continuously executes steps 608-620 until the entire Pd count sequence 618d for the trapazoidal-shaped velocity versus time profile for the target velocity Vl has been exhausted. In this connection it is noted that the drum cycle T ct is not complete until the settling time interval T s which is allowed for damping any overshoot of the motor drive shaft 122 is complete.
  • step 620 the microprocessor 502 transmits a status message, step 624, to the postage meter's computer 41 and the program loops to idle 606. Thereafter, the foregoing steps 606-622 of the main line, servo-control, idle loop are continuously executed by the microprocessor 502 in accordance with the above discussion until the main power switch 24 is opened by the operator.
  • the serial communications program 700 includes the transmit status routine 704.
  • the latter routine 704 includes the steps of receiving and decoding any message, step 706, and invoking the execute command routine, step 708, both of which steps are self explanatory.
  • step 708 the microprocessor 502 executes the routine 800 commencing with the step 802 of inquiring whether or not the decoded message is an enable command. Assuming the answer is yes, an enable status flag is set, step 804, to indicate that an envelope is to be fed to the drum 38. Whereupon the A.C. motor relay 52 is energized, step 806, for feeding the envelope to the drum 38, and the transmit status routine is invoked, step 808. On the other hand, assuming the decoded message is not an enable command, step 802, a enable status flag is cleared, step 810. Whereupon the A.C. relay is deenergized, step 812, and the status transmit routine is invoked 808.
  • step 806 the microprocessor 502 executes the routine 702 commencing with the step 710 of inquiring whether or not the drum cycle is complete. Assuming completion of the drum cycle, a drum cycle complete message is transmitted to the postage meter's computer 41, step 712. On the other hand, assuming the drum cycle is not complete, an inquiry is made as to whether or not the A.C. relay is energized, step 716, and, if it is, an A.C. relay energized message is transmitted to the postage meter's computer 41, step 718. If however the drum cycle is not complete, step 710, and the A.C. relay is not energized, step 716, then, an A.C.
  • relay deenergized message is transmitted to the postage meter's computer 41, step 720.
  • drum cycle complete, step 710, A.C. relay energized, step 716, or A.C. relay deenergized, step 720 the microprocessor 502 returns to the idle 606 of the main line program 600.
  • postage meter as used herein includes any device for affixing a value or other indicia on a sheet or sheet like material for governmental or private carrier parcel, envelope or package delivery, or other purposes.
  • private parcel or freight services purchase and employ postage meters for providing unit value pricing on tape for application on individual parcels.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Security & Cryptography (AREA)
  • Devices For Checking Fares Or Tickets At Control Points (AREA)
EP19850112601 1984-10-04 1985-10-04 Frankiermaschinenvorrichtung mit mikroprozessorgesteuertem Gleichstrommotor und Verfahren zu dessen Gebrauch Expired - Lifetime EP0177057B1 (de)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US65754684A 1984-10-04 1984-10-04
US06/657,569 US4631681A (en) 1984-10-04 1984-10-04 Microprocessor controlled d.c. motor and application therefor
US657546 1984-10-04
US657569 1984-10-04

Publications (3)

Publication Number Publication Date
EP0177057A2 true EP0177057A2 (de) 1986-04-09
EP0177057A3 EP0177057A3 (en) 1988-09-07
EP0177057B1 EP0177057B1 (de) 1992-03-25

Family

ID=27097430

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19850112601 Expired - Lifetime EP0177057B1 (de) 1984-10-04 1985-10-04 Frankiermaschinenvorrichtung mit mikroprozessorgesteuertem Gleichstrommotor und Verfahren zu dessen Gebrauch

Country Status (2)

Country Link
EP (1) EP0177057B1 (de)
DE (2) DE3585716D1 (de)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2208828A (en) * 1987-08-19 1989-04-19 Pitney Bowes Inc Drive control system for imprinting apparatus
AU602613B2 (en) * 1988-10-14 1990-10-18 Pitney-Bowes Inc. Drive control system for imprinting apparatus
FR2684335A1 (fr) * 1991-11-29 1993-06-04 Alcatel Satmam Dispositif de commande pour machine d'impression a la volee, et procede correspondant.
EP0547922A2 (de) * 1991-12-19 1993-06-23 Pitney Bowes Inc. Postbearbeitende Maschine mit Druckzylindersteuersystem
GB2271962A (en) * 1992-11-02 1994-05-04 Hussain Matlub Controlling a printing unit in response to the sensed speed of the substrate therethrough.
EP0669602A2 (de) * 1994-02-28 1995-08-30 Pitney Bowes Inc. Verfahren zum Steuern der Drucklänge bei einer Frankiermaschine
FR2730668A1 (fr) * 1995-02-20 1996-08-23 Secap Dispositif et procede de pilotage d'une machine d'impression notamment de tambour d'affranchisseur
US6226559B1 (en) * 1995-12-14 2001-05-01 Pitney Bowes Inc. Method of providing real time machine control system particularly suited for a postage meter mailing machine
EP1363247A2 (de) * 2002-05-14 2003-11-19 Kabushiki Kaisha Toshiba Stempelgerät für Papierblätter

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4016467A (en) * 1975-03-10 1977-04-05 Pitney-Bowes, Inc. Servodrive apparatus for driving the postage printing drum in a postage meter
DE2946861A1 (de) * 1978-12-16 1980-06-19 Max Hetzel Numerische steuerung eines mehrphasenmotors mit magnetisch polarisiertem rotor
US4263537A (en) * 1979-02-05 1981-04-21 Olympia Werke Ag Controlled positioning of a motor shaft

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4016467A (en) * 1975-03-10 1977-04-05 Pitney-Bowes, Inc. Servodrive apparatus for driving the postage printing drum in a postage meter
DE2946861A1 (de) * 1978-12-16 1980-06-19 Max Hetzel Numerische steuerung eines mehrphasenmotors mit magnetisch polarisiertem rotor
US4263537A (en) * 1979-02-05 1981-04-21 Olympia Werke Ag Controlled positioning of a motor shaft

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
IBM TECHNICAL DISCLOSURE BULLETIN, vol. 24, no. 10, March 1982, New York B.R.CAVILL, D. DODGEN AND D.C. THOMAS "Closed loop stepper control with auto synchronization of encoder feedback" pages 5013-5014 *

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2208828B (en) * 1987-08-19 1991-09-11 Pitney Bowes Inc Drive control system for imprinting apparatus
GB2208828A (en) * 1987-08-19 1989-04-19 Pitney Bowes Inc Drive control system for imprinting apparatus
AU602613B2 (en) * 1988-10-14 1990-10-18 Pitney-Bowes Inc. Drive control system for imprinting apparatus
US5471928A (en) * 1991-11-29 1995-12-05 Neopost Industrie Control device and method for "on the fly" printing machines
FR2684335A1 (fr) * 1991-11-29 1993-06-04 Alcatel Satmam Dispositif de commande pour machine d'impression a la volee, et procede correspondant.
EP0545769A1 (de) * 1991-11-29 1993-06-09 Neopost Industrie Steuervorrichtung für Druckmaschine für fliegenden Druck und entsprechendes Verfahren
EP0547922A2 (de) * 1991-12-19 1993-06-23 Pitney Bowes Inc. Postbearbeitende Maschine mit Druckzylindersteuersystem
EP0547922A3 (en) * 1991-12-19 1995-04-05 Pitney Bowes Inc Mailing machine including printing drum control system
GB2271962A (en) * 1992-11-02 1994-05-04 Hussain Matlub Controlling a printing unit in response to the sensed speed of the substrate therethrough.
EP0669602A2 (de) * 1994-02-28 1995-08-30 Pitney Bowes Inc. Verfahren zum Steuern der Drucklänge bei einer Frankiermaschine
EP0669602A3 (de) * 1994-02-28 1999-08-18 Pitney Bowes Inc. Verfahren zum Steuern der Drucklänge bei einer Frankiermaschine
FR2730668A1 (fr) * 1995-02-20 1996-08-23 Secap Dispositif et procede de pilotage d'une machine d'impression notamment de tambour d'affranchisseur
WO1996026502A1 (fr) * 1995-02-20 1996-08-29 Secap Dispositif et procede de pilotage d'une machine d'impression, notamment de tambour d'affranchisseur
US5813347A (en) * 1995-02-20 1998-09-29 Secap Device and method for controlling a printing machine, particularly a franking machine drum
US6226559B1 (en) * 1995-12-14 2001-05-01 Pitney Bowes Inc. Method of providing real time machine control system particularly suited for a postage meter mailing machine
EP1363247A2 (de) * 2002-05-14 2003-11-19 Kabushiki Kaisha Toshiba Stempelgerät für Papierblätter
EP1363247A3 (de) * 2002-05-14 2004-02-04 Kabushiki Kaisha Toshiba Stempelgerät für Papierblätter
US6840168B2 (en) 2002-05-14 2005-01-11 Kabushiki Kaisha Toshiba Paper sheet stamp apparatus

Also Published As

Publication number Publication date
DE177057T1 (de) 1989-01-05
EP0177057A3 (en) 1988-09-07
DE3585716D1 (de) 1992-04-30
EP0177057B1 (de) 1992-03-25

Similar Documents

Publication Publication Date Title
US4774446A (en) Microprocessor controlled d.c. motor for controlling printing means
EP0177048B1 (de) Vorrichtung und Verfahren für einen mikroprozessorgesteuerten Gleichstrommotor zur Steuerung einer Last
US4631681A (en) Microprocessor controlled d.c. motor and application therefor
US4635205A (en) Microprocessor controlled d.c. motor for indexing postage value changing means
US4638732A (en) Sheet handling apparatus
EP0177055B2 (de) Frankiermaschinenvorrichtung mit mikroprozessorgesteuertem Gleichstrommotor zur Steuerung einer Frankiermaschine und Verfahren zur Anwendung in derselben
US4665353A (en) Microprocessor controlled D.C. motor for controlling tape feeding means
EP0177051B1 (de) Druckvorrichtung mit Mikroprozessorgesteuertem Gleichstrommotor zur Steuerung der Druckwertauswahlmittel und Verfahren zum Betreiben der Druckvorrichtung
US4643089A (en) Apparatus for controlling printing means
EP0177057A2 (de) Frankiermaschinenvorrichtung mit mikroprozessorgesteuertem Gleichstrommotor und Verfahren zu dessen Gebrauch
US4220084A (en) Document endorser apparatus
US4016467A (en) Servodrive apparatus for driving the postage printing drum in a postage meter
CA2001394C (en) Microprocessor system controller for mail processing system applications
US4731728A (en) Postage meter with means for preventing unauthorized postage printing
CA1189598A (en) Printer
EP0372725B1 (de) Mikroprozessorgesteuerter Motorkontroller für schrittweise Verarbeitungskreisläufe
CA1232011A (en) Microprocessor controlled d.c. motor and application therefor
CA1239983A (en) Microprocessor controlled d.c. motor for controlling printing means
US4745346A (en) Electronic postage meter print wheel setting optimization system
JPS61160188A (ja) 郵便料金計ドラム用マイクロプロセツサ制御直流モ−タ
EP0547922B1 (de) Postbearbeitende Maschine mit Druckzylindersteuersystem
GB2039177A (en) Motor control system

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): CH DE FR GB LI

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: PITNEY BOWES INC.

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): CH DE FR GB LI

EL Fr: translation of claims filed
DET De: translation of patent claims
17P Request for examination filed

Effective date: 19890221

17Q First examination report despatched

Effective date: 19901029

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): CH DE FR GB LI

REF Corresponds to:

Ref document number: 3585716

Country of ref document: DE

Date of ref document: 19920430

ET Fr: translation filed
PLBI Opposition filed

Free format text: ORIGINAL CODE: 0009260

26 Opposition filed

Opponent name: FRANCOTYP- POSTALIA GMBH

Effective date: 19921228

PLBN Opposition rejected

Free format text: ORIGINAL CODE: 0009273

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: OPPOSITION REJECTED

27O Opposition rejected

Effective date: 19940513

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20020918

Year of fee payment: 18

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20020927

Year of fee payment: 18

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 20021023

Year of fee payment: 18

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20021031

Year of fee payment: 18

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20031004

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20031031

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20031031

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20040501

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20031004

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20040630

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PLAB Opposition data, opponent's data or that of the opponent's representative modified

Free format text: ORIGINAL CODE: 0009299OPPO