JPS6142289B2 - - Google Patents

Description

[Detailed description of the invention]

FIELD OF THE INVENTION The present invention relates to a programmable microcomputer control device capable of interactively inputting data. BACKGROUND Various types of machine control systems are known, for example for milling machines using various machining tools. Typically, such numerical controls provide signals to servo motors associated with the X, Y, and Z axes of the machine, respectively.
Programmed from perforated paper tape.
When modifications are made to a particular program, a new tape typically must be made away from the milling machine, slowing down the use of the machine. Other large computer control devices have been devised to control various machines, but these are expensive and large in size. A numerical control device of this type is shown, for example, in US Pat. No. 3,746,845. Furthermore, conventional control devices are not easy to handle and operate by unskilled personnel. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a programmable microcomputer control device which is free from the above-mentioned drawbacks and which is easy to operate even for unskilled personnel. Summary In order to achieve the above object, the programmable microcomputer control device for controlling the relative motion between a tool and a workpiece according to the present invention has the following features: (a) relative position between the tool and the workpiece; (b) a changeable memory capable of holding a control program and control parameters; and (c) coupled to the output of the instruction means and the memory. , a microprocessor unit operative to generate a control signal dependent on the output of the support means and the control parameters in accordance with the control program; (e) an interface means for transmitting a control program and control parameters from an external medium to the changeable memory and recording the contents of the control parameters in the memory on the external medium; (f) (g) data input means for loading control parameters into said memory via an externally accessible data input independent of the interface means; and (g) control parameters controlled by said microprocessor unit operating in accordance with said control program. a display means for displaying a control parameter question, the control parameter question comprising:
Display means includes questions displayed sequentially for data blocks and questions displayed separately for information used in the data blocks being questioned. The programmable microcomputer control device of the present invention allows the driver to make interactive inputs with assistance from the control device. Therefore,
The operation becomes easy, and even non-skilled people can handle the machine. Next, embodiments and drawings illustrating the present invention will be described. Although the controller is described with respect to a milling machine, the controller is broadly applicable to other types of equipment whose motion is controlled in a programmable manner. The embodiments and drawings are illustrative to facilitate understanding of the principle of the present invention, and are not intended to limit the invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a control cabinet, a control panel, and a three-axis milling machine suitable for operation therewith. Cabinet 11 contains the electronic hardware of the control system and can be placed anywhere behind or to the side of three-axis milling machine 13 by means of casters 12. An arm 14 extending upwardly and outwardly from the top of the cabinet 11 is connected to a control panel 15.
Install it so that it sticks out so that it can be easily accessed by drivers. The control panel 15 will be explained in detail later. Motion control signals and position information signals are transmitted between the control circuit and the servo motor assembly via cables 22, 2.
3,24. Enclosed X-axis servo assembly 16 and enclosed Y-axis servo assembly 1
7 is shown at the required position on the milling machine. Z
The shaft servo motor assembly 18 is shown without its conventional casing, and a limit switch subassembly 19 containing an encoder and limit switch is also shown. The X, Y, and Z axis servo motors are essentially the same, and each servo has its own limit switch subassembly (19) developed. The table 20 of the milling machine is moved in the XY plane in this example by a screw drive driven by servos 16,17. Z-axis spindle assembly 2
1 is rotationally driven by a spindle motor and moved in the Z-axis direction by a servo 18. 2a and 2b are block diagrams of the electronic hardware of the control device. microprocessor 3
1 receives clock pulses from a two-phase non-overlapping clock 32. In the illustrated embodiment, the microprocessor is a Motorola 6800 MPU. Microprocessor 31 is coupled to an 8-bit data bus and a 16-bit address bus. microprocessor 3
The address line from 1 is coupled to the address bus via line driver 33 and address decoder 34. The address information of address bus 35 is actually 8
divided into 8K decoded segments. for example,
Two segments can be allocated to RAM (Random Access Memory) 36, and the other segment can be assigned to one or more other memories or PIA
(peripheral interface adapter). A PROM (Programmable Read Only Memory) 37 is used to bootstrap the microprocessor 31 under initial startup conditions. For example, the information stored in PROM 37 allows microprocessor 31 to appropriately load programs into RAM 36 from a magnetic tape cassette input. It is the control program that resides in RAM 36 after initial setup that directs the main functions of the microprocessor and associated circuitry. A separate address decoder 38 is used to provide addresses for the RAM in the most economical manner. A similar address decoder is also used for PROM 37. A MUX (multiplexer) 39 multiplexes 64 external instructions into 8 instructions and accommodates an 8-bit data bus line. The particular set of eight addressed switches is selected by the address from the address bus on line 40 and the appropriate data output instruction is generated on line 41. A transceiver or line driver receiver 42 provides amplification and steering for the data bus branches that serve MUX 39 and display PIA 43. A line driver receiver 44 adjacent to the microprocessor 31 and
Transceiver 45 coupled between RAM 36 and the data bus is also of the same type as transceiver 42. The decoder and transceiver coupled to PROM 37 are also of the same type as decoder 38 and transceiver 45 coupled to RAM 36. Figure 7 shows an example of the MUX 39 wiring, where one of the eight binary addresses is applied to lines A0-A2 from the address bus, and the address signal is
Received at the CE input to MUX 39, decoder 34 addresses one of a series of eight switches indicated schematically at number 46. The appropriate data word, depending on the setting of switch 46, is
is placed as an output from the Z terminal of the transceiver 42. These switch settings can be made using mechanical limit switches, push buttons, or the like. Display PIA 43 (FIG. 3) can receive information from the data bus. PIA43, like other PIAs, has two sections:
There is a section and a B section. Address line 48 operates to address one of the A and B sections of PIA 43. When the A section of PIA 43 is addressed, data from data bus 47 is provided to PIA 43 via transceiver 42 and an 8-bit word is coupled to lamp display 49 shown in FIG. FIG. 3 shows lamp 50 coupled to lamp display 49. FIG. For the appropriate address via section A of PIA 43, lamp 50 is activated in response to the required level of the addressed data bit.
With respect to the appropriate address on line 48, CRT display 51 is addressed through section B of PIA 43. Over successive interpals, the data is sequentially fed to its PIA and rendered as alphanumeric characters by the internal circuitry of display 51.
Displayed on a CRT (cathode ray tube) 52. The X-axis PIA 53 is addressed via line 54 and interfaces with the milling machine's X-axis drive. Y-axis PIA 55 is addressed via line 56 and Z-axis PIA 57 is addressed via line 58. Since the drive control of these three axes operates essentially in the same way, the X-axis PIA53 and related motors
Amplifiers etc. will be explained in detail. As shown in Figure 4,
PIA 53 has an A section and a B section, and is addressable by the address lines 54 described above for each section A and B. When the A section is addressed, an 8-bit word is coupled to PIA by line 59, this word indicating the relative position. The output of an up/down counter forming the lower portion of servo interface 60 provides this position indication. The output of the B section of the PIA 53 is supplied to the servo interface 60. Appropriately addressed commands from the microprocessor 31 are coupled to a servo interface 60 which generates an analog voltage and applies it to an amplifier 6.
1 input. Amplifier 61 rotates motor 62 at an appropriate speed corresponding to this received data information. The feedback provided by tachometer 63 ensures accurate motor speed control by amplifier 61. An encoder 64 with appropriate encoding detects changes in the position of the milling table in the X direction, and this encoded information is provided to the up/down counter of the servo interface 60. In the case of Z-axis motion control, this encoder senses tool head position rather than table position. Feed rate override PIA 65 is connected between address bus 35 and transceiver 66 . As shown in FIG. 6, the PIA 65 has an A section and a B section, each of which is coupled from the data bus 47 and each of which is addressable by a 2-byte address. Multiplexing circuit 69
selects the output of one of potentiometers 67 and 68 at a given time upon receiving a selection instruction from the microprocessor. The analog voltage indication from the selected potentiometer is coupled to analog to digital converter 66 via line 70. The potentiometer 67 is a means for adjusting the spindle feed rate, and the potentiometer 68 is a means for adjusting the feed rate of the milling machine table. The digital output from transducer 66 is utilized by microprocessor 31 to influence the programming speed of the table or spindle. The 100Hz clock starts interrogating the feedrate override circuit. This will be discussed later. Feedrate correction information from potentiometers 67 and 68 is coupled to the machine control relays via relay drivers. A tool change PIA 71 (FIG. 2b) may optionally be provided and is coupled to the data bus via a transceiver 72, addressed in a manner similar to that previously described. As shown in Figure 5, the A section of PIA71 is connected to limit switch controller 7.
3 receives 8-bit words indicating the status of various limit switches. The B section of PIA 71 provides commands from microprocessor 31,
This command affects a solenoid driver 74 and a pneumatic solenoid 75 which is actuated by air from an air source 76. These solenoid drivers and solenoids position the appropriate tools required by the microprocessor into working positions on the milling head. Tape cassette PIA 77 (FIG. 2b) is coupled between address bus 35 and data bus 47 via transceiver 78. PIA77 is
Provides an interface with the tape cassette used to load RAM 36. Furthermore,
The subsequently inserted cassette is used to record the program stored in the RAM via the PIA 77. As shown in FIG. 8a, cassette control data is coupled to the cassette via line 79 via PIA 77. As shown in FIG. 8b, front panel switch 80 provides inputs via MUX 39 to control cassette operation. The microprocessor can also read data from tape cassette 81 via read commands. A spindle speed PIA 82 (FIG. 2b) can also be optionally provided and is connected via a transceiver 83 between the address bus and the data bus. PIA 82 interfaces between the microprocessor interface and the motor that drives the spindle of a tool, such as a hole-drilling tool. Z
The amplifier and motor control operations for shaft spindle speed control are essentially the same as the motor control in FIG. FIG. 9 shows the front panel of the control device. The control panel includes a power switch 201 for supplying power to the control device and a key-locked inch-millimeter selector 202. Mechanical mode positioning control switch 203 has six positions that determine the X, Y, and Z directions (plus and minus) for movement in JOG mode. Additionally, the control switch 203 can be set to an AUTO mode for automatically positioning the X, Y, and Z axes based on programmed information, or to one of two TAPE modes for energizing the tape cassette. , can be placed. In the TAPE/MAN (manual) mode position, the cassette ON switch 226 and the cassette REWIND
Switch 227 can be pressed. When the ON switch 226 is pressed, the tape moves in the forward direction.
If the REWIND switch 227 is pressed, the tape will be rewound. In the TAPE/AUTO mode position, the cassette can be operated under the control of the stored program. In the DIG・R/O mode position,
The position in the X, Y, and Z axis directions is displayed. In this mode, the servos for those three axes are de-energized, the machine is enabled for manual operation, and the controller is used only as a digital readout. The machine mode switch spindle mode switch 204 has four positions. In the OFF position, only movement of the table in the X and Y directions occurs, and no movement of the spindle in the Z direction occurs. In the AUTO position, the spindle moves in the Z direction based on program instructions. In the MAN (manual)/ON position, the spindle is turned on and rotates, and the push button (SPINDLE
The first press of pushbutton 205 moves the spindle downwards, and the second press of pushbutton 205 returns the spindle to the uppermost position. In the MAN-OFF position, the spindle motor is deenergized and the Z-axis feed follows the program only after pressing pushbutton 205. However, it moves to the upper Z position and remains there until the push button 205 is pressed again. Pressing pushbutton 205 again returns the spindle to the uppermost position. Push button (MOTION HOLD) 206 is a pause button and stops all servo movements. When button 207 is pressed, tool coolant (COOLANT) is supplied to the vicinity of the workpiece. Button (START) 208 initiates milling operation when the controller is in operating mode or single cycle mode. Button (EMER STOP) 2
09 is an emergency stop button, which cuts off the power to the control device, motor, etc. Feed rate override control knob 210, 211
is provided. Knob 210 is for table feed rate override control, and when in the P (program) position, the programmed table feed rate is not changed. When the spindle control knob 211 is likewise in the P position, no change in the Z-direction feed rate of the spindle takes place. The effect on the program feed rate when the knob is moved to the right or left from the P position will be described later. Table knob 210 and spindle 211 are coupled to potentiometers 68 and 67, respectively, in FIG. A CRT (cathode ray tube) screen 212 is provided for displaying data blocks and the like.
A data entry keyboard 213 is provided for placing data into control memory in response to questions on CRT 212. Program keys 214-217
performs various functions related to inputting data into memory for program execution. NEXT・BLK
Key 214 advances the data block displayed on the CRT screen. ADV key 215 is
Advances the current question displayed at the bottom of the CRT screen to the next data item (ITEM) in the data block above. When a number from keyboard 213 is entered by ADV key 215, the CRT display advances to the data block of the corresponding number. The ERASE key 216 erases inputs made in response to specific items in the questions at the bottom of the CRT 212 (this means that the data block number
Only if it is not at the bottom of the CRT. ). When the data block number is at the bottom of the CRT, all data will be erased from that data block. The INC key 217 indicates, in response to a query, that the dimensions entered in the data block should be measured from the table or spindle's last position rather than its first reference position. The sequence of questions on the CRT screen for the data block is as follows: Data block number, machine mode, control mode, X
The sequence is dimension, Y dimension, Z dimension, feed speed, cutting speed, and tool number. Additionally, the X and Y dimensions and the number of repetitions in this X and Y direction are required for the step repeat block. In the milling block, a question is asked as to whether the milling is inside or outside. Therefore, the machine operator can confirm various parameters within the data block by selecting numerical inputs from the keyboard 213. By selecting the number keys on the keyboard, the driver can select the type of drilling, milling, etc., for example. The driver can control the machine operating mode, control operating mode, and partial program coordinates by entering the desired numbers on the keyboard. Four control keys 218 to 221 are provided. Key 218 places the program in ENTER mode. The key 219 is for the CHECK mode, the key 220 is for the SINGLE CYCLE mode, and the key 221 is for the OPERATE mode, and each mode will be described in detail later. Pushbuttons 222-224 act on various items in the memory of the control device. Table zero (TABLE
ZERO) button 222 instructs the microprocessor in the operating mode to search for the marker switch to obtain the zero position. If the program is at data block zero, table zero can be established for the entire length of table movement by pressing the table zero button 222 when the table is in the desired position. At this time, the program coordinates are measured from this position.
The button (TOOL CAL) 223 similarly calibrates the tool. Pressing the tool calibration button 223 at data block zero establishes an individual tool length calibration for each tool number on the display. Calibration of the tool length can be performed by manually lowering the tool along the Z-axis to the desired zero reference point with the tool mounted on the spindle and pressing pushbutton 223 at this time. These calibration operations are further explained in the program flowchart. A MASTER CLEAR pushbutton 224 clears machine setup information when the controller is in data block zero. If the microprocessor is in another data block operation, pressing pushbutton 224 will cause data block 1 to be activated.
All data is cleared from -99. Tape cassette deck 225 accommodates magnetic tape cassettes. This tape cassette can read and write data to and from the RAM. When mode switch 203 is in the TAPE AUTO mode, the contents of the data block are recorded on the tape cassette. Also, previously recorded data is read from the cassette and placed in the memory of the control device, thereby reproducing the program defined for processing the workpiece to provide the desired portion. Pressing the pushbutton 226 turns on the tape cassette deck, and the pushbutton 227 performs playback or rewinding after recording. The control key 203 is TAPE for read function, write function, and data search function.
Controlled by the data entry keys when in the AUTO position. If the control key 203 is set to the TAPE MAN position, the tape button 226,
227 can be activated. 10 and 11 show the Z-axis drive and positioning device. The Z-axis drive provides vertical servo motor controlled feed drive for the milling machine spindle, as well as precise linear positioning and feed rate control for vertical machining functions. Drive for vertical movement of the spindle is provided by a servo motor 241, which is mounted on a motor mounting plate 242. Motor mounting plate is Z
Adjustable relative to the axial spindle. The servo motor 241 is connected to a pair of timing belt pulleys 2
44 and a timing belt 246 to drive the ball screw 243. Preloaded double race ball bearing 247 that securely holds the ball screw 243
allows the ball screw to rotate without shaft end play. The inner race of the bearing is secured by a lock nut 248 and an adjacent lock washer. The outer race of the bearing is connected to the retainer cap 2.
52 and cap screw 253 to the main frame 2.
51. The main frame 251 is secured to the head of the milling machine by a retainer plate 254 and cap screws 256. Vertical motion of the spindle is obtained by rotating the ball screw 243 to drive the preload ball nut assembly 257. Ball nut assembly 2
The Z-axis carriage 258 to which 57 is attached has four V
The mold roller 261 moves vertically along the V-shaped guide groove 259 . The roller 261 is supported on the carriage 258 by a carriage adjustment stud in the carriage portion 262 and a lock nut 263. This adjusting implant screw has an eccentric shaft portion, and a V-shaped roller 261 is mounted on this shaft portion.
The stiffness of the carriage can be adjusted by changing the position of the V-roller by means of its eccentricity, thereby achieving the desired stiffness. A shaft rod 264, which forms the actual drive link between the spindle and the Z-axis carriage 258, is attached to the carriage 258 by a pair of bearings 266. These bearings 266 have a flexible inner race that is connected to a bearing lock nut 267 and a lock washer 268.
It is installed in a pre-loaded state by being pushed in by. The shank rod 264 is rigidly mounted within the milling machine spindle in tension by using the spindle shank rod bearing and a tool adapter (not shown) that is screwed onto the rod. In summary, servo motor 241 drives ball screw 243 via a timing belt drive, thereby driving preload ball nut 257. A ball nut 257 is attached to a carriage 258, which moves the carriage in the vertical direction, that is, in the left-right direction in the figure, and this movement is caused by the V-shaped groove 2.
59 and rollers 261 guide. This drives the shaft rod 264 mounted on the carriage 258 by a ball bearing 266 in the axial direction.
These bearings 266 control the spindle rotation and Z
They become independent of axial movement. Therefore, the milling spindle is connected to the tool adapter (not shown).
This is driven by being held by
Allows precise vertical control of the spindle when using a limit switch assembly, described below. Limit switch assemblies have been used to provide a mounting method in which the limit switch and encoder are mounted on separate mounts to provide accurate measurements over long distances in less space.
This provides a stable, edge play-free mounting for the encoder. The main frame 269 of the limit switch assembly is attached to the motor mounting bracket 242 by shoulder bolts 271 and lock nuts 272. This provides adjustable mounting for timing belt tension. After the desired installation is completed, it is secured by set screw 273 and lock nut 274. A driven belt 276 driven by a pulley attached to a servo motor shaft extension drives a driven shaft 277. This driven shaft is fitted between two bearings 278 and 279 in the main frame;
9 outer race retainer 281 and rear bearing 2
This is done by means of a snap spring 282 on the outer race of 78. The shoulder of the driven shaft 277 serves as a pushing member, and the nut 283 provides adjustment for the bearing 279. A very fine thread is cut in the driven shaft 277 to obtain a ratio between the actual rotational advancement of the servo motor shaft and the advancement of the limit switch pawl 284. A guide rod 286 for preventing rotation of the limit switch pawl 284 is attached to the main frame by a cap screw 287. As shaft 277 rotates, limit switch pawls 284 perform linear movement to actuate appropriate limit switches 288. The limit switch may be a mechanically actuated switch as shown, but it may also be of other known types, such as photoelectric. To adjust the limit switch position, loosen the screws and washers 289, 291, and slide the limit switch bracket 292 along the keyway of the main frame 269. Another setting method is to remove the guide rod 286 and use the pawl 284.
Rotate to the desired setting position and reinstall the guide rod. Encoder 293 is mounted to main frame 269 and its encoding disc (not shown) is secured to shaft 277. FIG. 12 shows a simplified diagram of the feed rate override control system of the present device. 0 to 0 from the table feed speed adjustment potentiometer 301 and the spindle feed speed adjustment potentiometer 302
The +5V analog value is switched by analog multiplexer 303. Potentiometers 301 and 302 are each 10KΩ and correspond to potentiometers 68 and 67 in FIG. A ₀ and A ₁ output of PIA304 is multiplexer 3
03, and selects one of the voltage values of the table potentiometer and spindle potentiometer, and connects the analog-to-digital converter 3.
06 encodes the voltage value into an 8-bit code. The 8 parallel bits are the 0-7 bit output of converter 306 and the input B ₀ - of PIA 304.
Connected to B ₇ . The device program scans the data output of PIA 304 to determine if a data valid condition exists such that inputs B ₀ -B ₇ are coupled to data outputs D ₀ -D ₇ . The valid data output from converter 306 is connected to the A ₇ input of PIA 304. Potentiometer 307 sets converter 306 to a full scale 8-bit output for a particular input voltage. Therefore, when the output from multiplexer 303 is the maximum +5V, potentiometer 3
The outputs from 07 to the inputs of analog-to-digital converter 306 are set so that bit outputs 0-7 of converter 306 all produce high outputs. Potentiometer 309 sets a zero value for the OV input. Both ends of potentiometer 309 are +5V and -5V. potentiometer 3
The output of 09 is coupled to the nulling input of converter 306 by line 311 through a 100KΩ resistor. Line 311 is a 1KΩ voltage divider circuit for zero adjustment.
Grounded through a resistor. Analog-to-digital converter 306 is optionally supplied with various other inputs, such as voltage sources and current references. As the converter 306, for example, a Teledyne Model 8700CN can be used. 100Hz clock 312 converts pulses to converter 30
6, the converter starts outputting on output lines 0-7. The output of clock 312 is also
Coupled to the CB ₁ input of PIA 304 as a device interrupt. This interrupt is sent to the program element with X, Y,
Service the Z servo routine. This interrupt operation will be discussed later with respect to the device program flowchart. While servicing the X, Y, Z servo routine, potentiometers 301 and 302
Changes in table feed rate and spindle feed rate settings in are recognized by the machine program and the rates are recalculated. 12th
As shown in the figure, this data output is
3, and various timing and address outputs of the PIA 304 are coupled to the address decoding and timing section 316 of the microprocessor via line 314.
is combined with As shown in Figure 13a, the outputs of data lines 7-0 (from most significant bit to least significant bit) have various changes in feed rate. When only the most significant bit is high (indicating a mid-range potentiometer output of 2.5V), the programmed feedrate value is used. If the potentiometer is set from 0 to 2.5V, all bit weights of lines 7 to 0 will be
If less than 1/2 occurs, the programmed value of the feed rate is multiplied by the fractional value of that bit rate divided by 128 or ²⁷ . The number 128 is ²⁷ and represents 1/2 of the bit weights of lines 0-7, ie, all of the bit weights of lines 0-6. If the potentiometer is set between 2.5 and 5V, it will be more than 1/2 of the bit weight. 2 shown
In two example conditions, the potentiometer is
At 5V, all bits are high and the feed rate is the programmed value plus 6in/min (approximately 150mm/min). When the value corresponds to 3/4 of the bit rate, bits 6 and 7 are high, and the feed rate becomes the programmed value plus 3 in/min (approximately 75 mm/min). As shown in Figure 13b, when the control is in JOG mode and the weight is 2.5V or 1/2, the feed rate is e.g.
It is set to 50in/min (approximately 1270mm/min).
When the voltage is between 0 and 2.5V, the 50 in/min is multiplied by the fractional value of the bit weight divided by ²⁷ . voltage is
When the voltage is 2.5~5V, the feed rate is 140in/min (approximately 3500in/min).
mm/min) multiplied by the fractional value obtained by dividing the bit rate by ²⁸ , or 256. Next, a flowchart of the basic operation of the software related to the control device of the present invention will be shown as a table.
These software operations are broken down into subroutines, and each underlined step within a block of the table is described with respect to its various substeps after the table. Generally, software in the memory of a microprocessor controls all basic functions of the machine.
The software monitors the control panel's keyboard and control switches. The software is also
Generates a message displayed on the CRT screen,
Activate the magnetic tape cassette unit. The operation of the cassette unit allows partial programs to be loaded onto or from tape. The software also controls the three axes X, Y, Z servos and controls the sequence and motion of the machine during partial program execution.

[Table] In Table 1, if power is supplied to the device from the control panel, the program starts running at BEGIN. This places each PIA in a predetermined state, clears variable memory to start from zero condition, and activates device interrupts.

[Table] Table 2 shows the interrupt program (INTERRUPT).
PGM) and is the main part of the servo positioning device, which is controlled by the command of an external clock.
times/second. Regardless of what the main program is executing, the interrupt program will execute every time a 100 Hz clock pulse is received from start to finish. This program checks which keys are pressed in a boring manner and stores those values for later retrieval by the main program. In the servo portion of the interrupt program, the desired position is compared to the actual position to form an output error signal to the digital-to-analog converter. The program determines the desired position by taking movement commands from the command buffer and adding them to the error signal. The changes in encoder readings for a particular calculated axis movement are summed to define the movement that occurred during the last interval. The resulting error signal is the difference between the desired position and the actual position. This is fed into the speed command of the motor control and adjusts the axial speed to obtain the desired position.
The X, Y, and Z axis movements are inspected for each 100 Hz clock pulse. To produce any axial movement, it is only necessary to supply a MOVE value to the command buffer. These movement values are the distances to be moved in 1/100 seconds regarding each axis. When successive movement values are loaded into the command buffer, each interrupt takes one value from the movement values and executes. This axial movement occurs at a speed proportional to the value of the movement value. As shown in Table 1, the SET MODE program is executed after BEGIN. This program is also executed each time the machine operator selects a new mode. This program sets initial conditions and selects modes (ENTER, CHECK, SINGLE, OPERATE or
Jump to one of the EMERGE-NCY/STOP).

Table 3 describes the first of the five available modes reached from the set mode program of Table 1. For ENTER mode, an enter program is executed. The program starts with data block 1, displays the values in this data block, and asks questions about each item in this data block. By pressing various keys on the control panel, the driver can advance to the next item in the data block or alternatively modify or enter values for the particular item being displayed. In enter mode, all items are displayed on the CRT screen and then questions are displayed at the bottom of the screen for each item in that data block.
The driver can make keyboard data and mode selection inputs via the keyboard for each question. The data block progress key and the question item progress key are located on the control panel shown in FIG. When the driver is satisfied with a particular data block, he presses the data block advance key to increment the data block number and the next data block is displayed on the CRT screen. If the next data block is not yet programmed, it is created by transferring data from the previous data block. This allows values that do not change to continue and the driver does not have to enter them again on the keyboard. If a data block zero is required, another enter program is executed which allows entry of X and Y offsets and tool data. The tool calibration length can be entered by actually moving the Z-axis to a certain position and recording this point.

【table】

[Table] Table 4 shows the enter DB zero routine, and
The table shows the current data block display routine from the enter program in Table 3.

Table 6 shows the second of the five available modes shown in Table 1, the CHECK mode. This check mode can be entered through the set mode and allows all data blocks programmed to date to be displayed continuously. This mode is for the driver's convenience to ensure that the correct program required is in memory.

【table】

[Table] Tables 7 and 8 show the following two modes that the program can enter. The single mode program in Table 7 sets the single step flag and proceeds to the OPBRATE program described below. The emergency stop program shown in Table 8 is entered when the emergency stop switch on the control panel is pressed.
Stop all motion and wait until the machine operator presses a button to put the machine into test mode. In the inspection mode, the emergency stop condition is canceled.

[Table] Table 9 shows the fifth mode, ie, the OPERATE mode, which is the main mode for automatic processing. As shown in Table 9, the operating program is Z
Allows manual adjustment of the axis spindle and calibration of the table as well as execution of data block partial programs. If you press the START key in JOG mode, the displacement will be input and the feed rate will be 50in/
min (approximately 1270 mm/min), and the movement execution (DOMOVE) program is executed.

[Table] Table 10 shows the DOMOVE program described above.
This program calculates the movement increments and supplies them to the interrupt program, which actually drives the three-axis servos. This program determines whether movement is required in the Z direction or in the XY direction. When movement in the XY directions is required, the program receives the feed rate and modifies it according to the feed rate potentiometer (POT). next,
The required movement in the X direction is the required X position XD
It is calculated by taking the difference between and the current position X.
The same calculation is performed for the Y direction, and the moving distance DL is determined by √ ² + ² . The number of repetitions required to travel this distance at a given feed rate is then calculated. NNN is equal to the distance to be traveled multiplied by the number of steps per minute. This number of steps is in this case 6000, which is based on 100 executions per second of the interrupt program. Now that the number of steps has been calculated, the dimension of each step (eg, the X increment) is calculated by dividing the distance in the X direction to be moved by the number of steps. Similarly, the Y increment is the total Y movement distance divided by the number of steps. This X increment and Y increment are added NNN times to the X and Y positions. This is done by the following INTERPOLATE program. When movement in the Z direction is required, calculate NNN and Z increment in the same way. The INTERPORATE program calls the lead screw correction program five times per second. The interpolation program checks whether the feedrate potentiometer has changed. If JOG mode is running, this program returns whenever the driver releases the start button. After doing the above, the interpolation program should be
Count down NNN. If this value is zero, the movement is complete and the program moves to the final movement (FINISHMOVE). If not,
Add the previously calculated increment to the actual position to update the position for each of the three axes. Next, calculate the movement (MOVE) value, and if there is room in the command buffer, place the three movement values in the buffer. Since the command buffer value is used by the interrupt program, it is necessary to wait until the value changes in the interrupt program. The interpolation program thereby precalculates the various displacement values and ensures that data is always available to the interrupt program. The interpolation program also displays the current instantaneous values of the X, Y, and Z values on the CRT screen. It then goes through a loop and waits to calculate the movement value and place it in the command buffer. When NNN becomes zero, the movement is complete and the X position reaches the desired X value. The final move (Table 29) sets them exactly equal and returns to the calling program. As can be seen, if the XD, YD, or ZD values are set to a desired position, the DOMOVE program will move the servo to that desired position at the appropriate feed rate.
FRATE subroutine and lead screw correction (LEAD
SCREW COMP) subroutines 11 and 12
Shown in the table.

【table】

[Table] In the OPERATE program shown in Table 9, when the AUTO position mode is selected and the start button is pressed, the AUTO program is called and the partial program stored in the data block is executed. . XYCAL, ZTCAL ZZERO and
XYMARKER subroutines 13th, 14th, 15th, 16th
Shown in the table.

【table】

【table】

【table】

[Table] As shown in Table 14, Z-axis spindle calibration is performed by adding the Z offset from the previous tool to the Z position.
This is done by determining the absolute Z position from time to time. The current tool calibration length for the new tool is then entered as the current offset distance, and this distance is subtracted from the absolute Z position described above to obtain the new Z position for the current tool. next,
This new Z offset is saved for subsequent Z calibration routines. This calibration length (CALLE
NGTH) is obtained as one step in the DBZERO calibration operation shown in Table 4. As mentioned above, when manually moving the Z-axis to a desired zero reference plane, a tool length calibration value can be entered using the tool calibration button 223. Generally, a tool length calibration for each tool used is entered and stored in the microprocessor's memory and recalled when each tool is used. The AUTO program reads the data block and determines the type or mode of machining (POSITION, MILL, DRILL, BORE). Each mode is a sequence of operations that causes the milling machine to perform a desired operation. Table 17 shows the automatic sequence starting with NEXTDB.

【table】

[Table] If the selected function or mode is positioning (POSI)
TION) (Table 18), retraction is performed to raise the Z spindle. To do this, set the desired Z value to 10 inches, set RAPID, and run the DOMOVE program until the Z upper limit switch is activated. Z
After raising the axis, read the X,Y position from the data block, set rapid and execute DOMOVE. This causes the table to move in the XY plane,
The commanded XY position in the data block. WAIT ERROR SMALL
delays this program until the servo is within a few thousandths of a second. After this, part of the NEXTDB program (Table 17) is executed. NEXTDB in Table 17 checks for datablock stop and either returns to the operating program or proceeds to the next datablock. If the program is in single cycle mode or if the tool is to be replaced, control returns to the operating program. Otherwise, the loop repeats, jumping to the required program and executing its data block.

[Table] Table 19 shows the milling (MILL) program. First, lower the spindle to the Z downward position,
Take the XY data from the data block and
Run DOMOVE. Therefore, the table moves to that XY value at the programmed feed rate.
After DOMOVE, a small error waiting subroutine is executed and the next data block is checked. If the next data block is not in milling mode, perform Z retraction and raise the spindle. In milling, if an inner or outer frame milling motion has been entered in the data block before the DOMOVE step, the program moves to FRAME. The driver selects inside, outside, or neither for possible frame machining of the milling data block. As shown in Table 19, if inside or outside milling is selected, the FRAME milling subroutine is executed (Table 20).

For example, in the case of milling an inner frame, the first data block positions the tool at the desired location on the workpiece and begins frame milling. The next data block is the milling data block in which the operator has inserted the desired inner frame milling and entered the XY distances that the tool should travel. No.
As shown in Table 20, the Z-axis moves in four directions to complete frame processing, and the spindle is pulled up. next 21st
As shown in the table DRILL, after the intermediate block error wait, if the next data block contains an inner or outer frame milling step, the X, Y position is Offset by 1/2 of the diameter. This allows the operator to program the X and Y dimensions in which the frame milling is actually to be performed and does not have to take them into account. After raising the Z axis in Table 20,
The XY offset is canceled so that the XY positioning returns to its true value on subsequent operations.

[Table] Table 21 shows drilling (BORE) and drilling (DRILL)
Indicates mode. Drilling mode sets the drilling flag and proceeds in the same manner as drilling mode. The drilling mode is performed as follows. First, the spindle can be retracted. Get the XY values from the data block. Move rapidly to the position of that XY value and execute the small error waiting subroutine. Rapidly move to the upper Z position and perform the small error standby subroutine. If repeat drilling (PECK) mode is set, another DOPECK program is executed next. If this is not the case, that is, in the case of normal drilling,
Z is moved to the lower position at the programmed feed rate. Check the next data block type with a delay of 3/10 seconds. When this is milling, processing is performed using the data block without pulling up the spindle.
When the drilling flag is set, the spindle is slowly pulled upwards in Z at the programmed feed rate. If not, a Z retraction is performed to raise the spindle back to the top position and the next data block in the sequence is then executed.

【table】

【table】

【table】

【table】

【table】

[Table] Table 22 is the spindle retraction subroutine,
Table 24 shows the subroutine for obtaining XY values from the data block, Table 24 shows the small error wait subroutine, Table 25 shows the Z down subroutine, Table 26 shows the Z up fast subroutine, and Table 27 shows the Z up slow subroutine. During every movement, a lead screw correction value is calculated and applied to the movement. This multiplies the position against the lead screw error programmed by the jumper wire and calculates the lead screw correction value. This modified value is added to the desired position when provided to the interrupt program.

Table 28 shows the Repeated Drilling (PECK) program, which is a drilling mode option that divides the distance between the drill strokes, ZUP and ZDOWN, by the desired number of repeated drillings. This distance ZD is used to move the Z desired position into the workpiece N repeated drillings, pulling it into the ZUP between each drilling. This facilitates removal of chips when drilling large holes.

【table】 Table 29 shows the final transfer program.

[Table] Table 30 shows the REPEAT program, which allows the execution of overlapping steps and repetitions. This allows a pattern to be repeated N times at various X or Y offset distances. When steps and repeats are initiated, certain conditions are stored in the step/repeat (STP/REP) stack. When the repeat block is reached, the repeat numbers NX, NY are stored on the stack and a loop is formed back to the starting data block. Each time a REPEAT is reached in this loop, the X or Y position is modified by the step value and the count is decremented. When both the X and Y counters reach zero, it indicates that the pattern has been repeated a predetermined number of times, and the next data block is executed. A repeating program can be configured such that up to three loops can be stacked, for example.
The start data block of one loop is flagged by selection by the driver as the STP/REP block shown in the automatic program in Table 17. This data block designated as STP/REP also contains normal information such as MILL, DRILL, etc. This flagged block can be followed by one or more data blocks containing the remainder of the steps of the operation to be repeated. The repeat block includes an incremental X dimension and count of X actuations, an incremental Y dimension and a count of Y actuations. The program performs all X-direction repeats for a given Y dimension, then moves to the next Y-dimension and performs another series of X-direction repeats. A simple type of repetitive program performed by a milling machine operator is a pattern of drilling holes in a workpiece in an array, such as a 2 x 3 or 4 x 5 array. The use of repeat blocks saves the effort of entering data into data blocks each time for the same type of work. The use of frame milling operations described above is an exemplary programming tool for the machine operator.

[Brief explanation of the drawing]

1 is a front view of a milling machine suitable for operation with a control device according to the invention, and FIGS. 2a and 2b are block diagrams of the hardware associated with the control device. Figures 3-8 are detailed views of the peripheral interface adapter PIA of Figures 2a and 2b, along with the external devices with which they interface. FIG. 9 is an enlarged front view of the control panel shown in FIG. 1. 10th
The figure is a sectional view of the Z-axis servo device shown in FIG. 1. FIG. 11 is a top view of FIGS. 1 and 10. FIG. 12 is a feed rate adjustment circuit diagram. FIGS. 13a and 13b are diagrams showing the adjustment by the feed speed adjustment potentiometer when the control device is in the AUTO mode and the JOG mode, respectively. 13... Three-axis milling machine, 16, 17, 18... Servo device, 19... Limit switch subassembly, 2
0...Table, 21...Spindle, 31...Microprocessor, 36...RAM (random access memory), 37...PROM (programmable read-only memory), 39...MUX (multiplexer), 43, 53, 55, 57, 65 ,71,7
7, 82... PIA (peripheral interface adapter), 42, 45, 66... Transceiver, 67,
68... Potentiometer (for adjusting feed speed), 2
51...frame, 258...carriage, 261...
V-type roller, 264... Spindle, 277... Driven shaft, 284... Claw member, 288, 289... Limit switch, 293... Encoder.

Claims (1)

[Scope of Claims] 1. A programmable microcomputer control device for controlling relative motion between a tool and a workpiece, comprising: (a) a digital signal representing the relative position between the tool and the workpiece; (b) a changeable memory capable of holding a control program and control parameters; and (c) an instruction means coupled to the output of the instruction means and the memory, the control a microprocessor unit that operates to generate a control signal dependent on the output of the support means and the control parameters according to a program; (d) directing the control signal from the microprocessor unit to the required motion generating means; (e) an interface means for transmitting a control program and control parameters from an external medium to the changeable memory and recording the contents of the control parameters in the memory on the external medium; (f) the interface means (g) data input means for loading control parameters into said memory via externally accessible data inputs independent of said control program; and a display means for displaying, the control parameter question being:
A programmable microcomputer-controlled device comprising display means including sequentially displayed questions for data blocks and separately displayed questions for information used in the data blocks being questioned. 2. The device according to claim 1, wherein the interface means includes means for reading from and writing to a magnetic storage information input. 3. A programmable microcomputer-controlled device according to claim 2, wherein said reading and writing means comprises a tape cassette transporter.