-^ '>w/ /^-^o '^:w^/ ^o'"''^^- ' ^^^^^' ^ ,4^ "^^ -.^P** ^"^ "^^ \ /''..:::^>-e 'bV" :- -n^d^ or .*l9«v I »* - M » •'jk ^1 BUREAU OF MINES INFORMATION CIRCULAR/1988 j>-i A Testbed for Autonomous Mining IVIachine Experiments By William H. Schiffbauer UNITED STATES DEPARTMENT OF THE INTERIOR Information Circular 9198 A Testbed for Autonomous Mining IVIachine Experiments By William H. Schiffbauer UNITED STATES DEPARTMENT OF THE INTERIOR Donald Paul Model, Secretary BUREAU OF MINES T S Ary, Director Library of Congress Cataloging in Publication Data; Schiffbauer, William H. A testbed for autonomous mining machine experiments. (Bureau of Mines information circular; 9198) Includes bibliographical references. Supt. of Docs.: 128.27: 9198. 1. Mining machinery-Computer simulation. I. Title. II. Series: Information circular (United States. Bureau of Mines); 9198. -TN295.U4 [TN345] 622 s [622'. 028] 88-600360 CONTENTS Page Abs t ract 1 Introduction 2 Design objectives 3 Operating system software description 3 Programming language description 4 Hardware description <> 4 Application software 8 Modes of operation 8 System diagnostics mode 8 System exerciser mode 8 Closed loop mode 8 Browser mode 9 Scripting mode 9 System Integrity software 9 System confidence tests 9 Monitor 9 TAMME Initialization 9 Watchdog timer 9 Local user operation 10 Summary -. 20 ILLUSTRATIONS 1. Joy 16 CM mining machine 2 2. Operating system and hardware devices 3 3. TAMME hardware 4 4. Bubble memory cartridge 6 5. Menu flowchart 11 6. Closed loop test algorithm 14 7. TAMME and bltbus network 20 TABLES 1. Sensor connections to TAMME 7 2. Dlgltlal I-O channel assignments 8 UNIT OF MEASURE ABBREVIATIONS USED IN THIS REPORT A ampere psl pound per square inch op degree Fahrenheit. psia pound per square inch, absolute ft foot s second gpm gallon per minute St short ton in inch V volt ym micrometer w watt Mb megabyte MHz megahertz A TESTBED FOR AUTONOMOUS MINING MACHINE EXPERIMENTS By William H. Schiffbauer^ ABSTRACT The Bureau of Mines is conducting research that is aimed at making the mining industry more efficient in terms of both productivity and the health and safety of the worker. As part of this research the Bureau of Mines has integrated a testbed composed of computer and related periph- eral hardware to form an intelligent base for performing autonomous min- ing machine experiments. Although this particular application was con- figured for use on a Joy 16 CM mining machine, its generic structure facilitates its attachment to a variety of mining machine types. The multitasking multiuser computer can be set up for other applications by changing a bubble memory cartridge. The Joy 16 CM implementation in- cludes 96 digital input-output (I-O) ports, 32 analog inputs, 8 analog outputs, 2 serial data channels, and 1 printer port. Operation of the machine can be performed either through a local terminal or remotely through a modem hookup. This report describes a testbed for autonomous mining machine experiments (TAMME) — its hardware, software, and complete system integration — so that it can be used as a foundation for other applications. ^Electronics technician, Pittsburgh Research Center, Bureau of Mines, Pittsburgh, PA. INTRODUCTION Major problems threaten today's coal mining industry. Most of these problems can be traced to basic economics; i.e., providing a product that is both competi- tive and profitable. Through research, the Bureau of Mines is developing methods and devices that show promise in assist- ing private industry in making a competi- tive and profitable product, and also helping the workers to achieve these goals in a safe working environment. The TAMME system developed by the Bu- reau shows great promise toward making mining machinery more productive and safe for the workers by enhancing it with the latest computer technology. The TAMME is a collection of computer and peripheral devices, integrated into one chassis, and programmed to operate a Joy 16 CM mining machine (fig. 1). A modular I-O struc- ture permits attachment of TAMME to present and future monitoring or control devices. The hardware selected employs transformer and optical coupling, provid- ing extreme isolation from the noisy electrical environment presented by a mining machine. Additionally, a special power supply is used. The power supply, with transformer isolation and special circuit design, prevents any power fluc- tuations from entering the TAMME chassis. Throughout the hardware and software are a variety of diagnostic features that give the operator a status report of system health. Included in the design is a removable storage device called a bubble memory cartridge, that provides storage of operating system and applica- tion programs. The flexibility provided by TAMME allows it to be reconfigured for almost any monitoring and control application. The Bureau has created a tool that is useful for both research and production. It was constructed from a variety of off- the-shelf hardware and software so that its structure can be duplicated with a minimum of customization. Although this application of TAMME was specific to a Joy 16 CM mining machine, it can be easily applied to other mining machine types through modification of the software. FIGURE l.-Joy 16 CM mining machine. DESIGN OBJECTIVES The creation of TAMME was initiated to provide a base or testbed on a mining machine to allow Bureau researchers to experiment with making mining machinery autonomous, with the purpose of increas- ing production and making raining safer. The testbed was constructed with the latest technology and standardized inter- faces so that the product could evolve with the types of experiments being per- formed. The first step of the process was to establish control of the primary appendages of the machine without worry- ing about the actual position of the appendages. Then, with the help of the appropriate sensors, all of the append- ages and crucial systems on the machine were to be monitored, including the elec- trical and hyraulic systems. Next, closed loop control of the primary ap- pendages of the machine was to be estab- lished using the output of the sensors as a verification of position. The next objective was to produce a scripting mode of operation, to demonstrate a series of mining cycles completely controlled by the computer. This objective would be the starting point of the next phase of this ongoing research. Additionally, a major goal was to docu- ment TAMME so that industry personnel could duplicate and use it on their own machines for research or production. OPERATING SYSTEM SOFTWARE DESCRIPTION An Intel Corp. 2 iRMX86 operating system was used to form the software foundation for controlling the TAMME system. The iRMX86 was used because it is a real- time, multitasking, multiuser, custom- configurable operating system designed to support high-performance, time-critical applications. Because both iRMX86 and the host central processing unit (iSBC 286/12) are provided and supported by the same manufacturer, their choice as a team ^Reference to specific products does not imply endorsement by the Bureau of Mines. minimized the hardware-software failure bottleneck usually associated with system development. The customized iRMX86 operating system used on TAMME is activated on powerup. Once activated it creates a collection of simultaneously executing software appli- cations, called jobs, that provide soft- ware interfaces to the various pieces of the TAMME system. The jobs most visible to the system user are the human inter- face job and the extended I-O job. Other jobs are created but their purposes are beyond the scope of this paper. The human interface job gives the users and applications simple access to file and system management capabilities. Using support from other iRMX86 jobs, the human interface provides two simultaneous users for the TAMME system, a local user and a remote user. The extended 1-0 job is a group of software modules that provide users with system calls for direct management of hardware including the bubble memory, random access memory (RAM), interrupts, and 1-0 devices. Figure 2 shows the operating system environment and the hardware peripheral devices. Bubble memory Serial port Terminal Serial port Modem Parallel port Printer Analog 1-0 Digital 1-0 FIGURE 2.-0peratmg system and hardware devices. PROGRAMMING LANQUAGE DESCRIPTION All of the application programs created for TAMME were done in the PLM 86 programming language. PLM 86 is an Intel microcomputer-specific, block-structured, high-level language, that provides full access to the microcomputer architecture. Use of PLM 86 simplified the process of breaking up the software into individual modules dedicated to specific system tasks, which speeds up software produc- tion and minimizes bugs. HARDWARE DESCRIPTION A large collection of hardware formed the TAMME system. Hardware selection was carefully done to provide a base that was modular and standardized so that it could be reconfigured to an evolving series of experiments with a minimum of complica- tions. A portion of the TAMME system was designed using a previous Bureau develop- ment as a guide. -^ The present package of hardware is shown in figure 3. A de- scription of each of the components used to construct TAMME follows. ■^Schif fbauer, W. H. An Intelligent Remotely Operated Controller for Mining Machines. Paper in Proceedings of the Third Conference on the Use of Computers in the Coal Industry, ed. by Y. J. Wang, R. L. Grayson, and R. L. Sanford. A. A. Balkema, 1986, pp. 223-233. FIGURE 3.-TAMME hardware. Multibus I Backplane, Electronic Solutions, Nine-Slot Chassis Multibus I is an industry standard'^ microcomputer bus structure, that sup- ports distributed processing configura- tions using multiple processors, I-O boards, and peripheral boards. Multibus I was selected because of its extreme adaptability, and the large num- ber of commercially available devices that conform to this standard. Central Processing Unit (CPU) board , Intel iSBC 286/12 The iSBC 286/12 single-board computer is a high-performance 16-bit microcom- puter. It includes an 8-MHz 80286 micro- processor, together with a high-perfor- mance 80287 numeric data coprocessor and 1 Mb of zero-wait state memory. Addi- tionally, it has multiple serial and parallel expansion ports, and other expansion capabilities through two multi- module bus connections and the multibus card edge interface. The iSBC 286/12 card was the choice for TAMME system because at the time of selection, it was the newest state- of-the-art microcomputer board that could provide a real-time control system. Bubble Memory, TARGA Electronics, Solidrive The Solidrive consists of a removable 0.5 Mb bubble cartridge and a drive chas- sis. The drive chassis is mechanically and electrically configured to replace a standard 5-1/4-in half-height floppy disk drive. The bubble cartridge is used just as a floppy disk is used. The data stored in the bubble cartridge are permanently retained in the nonvola- tile, solid-state, magnetic bubble mem- ory. Once stored, data will be retained indefinitely without external power until ^Institute of Electrical and Electronic Engineer, IEEE Standard 796, System Back- plane Bus. they are intentionally overwritten or erased. The contents of the bubble car- tridge may be altered as often as is required since bubble memory is not sub- ject to read-write-erase wear out. The bubble memory cartridge was chosen over a floppy disk or Winchester disk, because bubble memory is immune to the effects of mechanical vibration because it has no moving parts. Figure 4 shows the Solidrive and the bubble memory cartridge. Sensor Conditioning Modules, Analog Devices, 3B series Each of the sensors attached to the mining machine are connected to TAMME through a conditioning module (see table 1). The 3B series of conditioning modules were chosen because they use transformer coupling, which provides max- imum mining machine electrical system isolation, and also because there are modules available for a large variety of sensor types. Analog-to-Digital Converter Card, Analog Devices, RTI 711 The RTI 711 is a complete single-board analog input card that interfaces with multibus-compatible computer hardware. It provides 32 channels of 12-bit resolu- tion, single-ended inputs, and has high common mode noise rejection. The RTI 711 was selected because it was compatible with the remainder of the system, required only a single supply voltage, and its power consumption was quite low. Digital-to-Analog Converter Card, Intel iSBX328 The iSBX 328 is a 16-channel 12-bit resolution device. This digital-to-analog converter was selected over other devices because of the number of channels provided in a com- pact package. FIGURE 4.-Bubble memory cartridge. Digital Input-Output, Opto 22 Opto 22 devices are a series of remov- able input or output modules that are optically isolated and can be used for both ac and dc signals with resistive and inductive loads. They provide com- plete electrical isolation between the computer to the control system, a main reason for their choice for the TAMME system. The TAMME system is presently config- ured to provide up to 96 inputs-outputs. The assignment of channels for the Joy 16 CM machine is shown in table 2, Uninterruptible Power Supply (UPS), Til Electronics The 170-W UPS provides transformer isolation from the mine power system. It eliminates virtually all transients and power fluctuations through its unique circuit design. Additionally, this UPS generates multiple dc voltages to TAMME instead of supplying ac voltages as would other power supplies. This feature eliminates an extra step in the power conversion process, makes the UPS more efficient, and consumes less power, thereby generating less heat in the com- puter housing. Chassis Mounting Considerations The Joy 16 CM mining machine is not a very good base for mounting delicate computer hardware. The extreme vibra- tion provided by it would certainly destory an unprotected system. It has TABLE 1, - Sensor connections to TAMME Module Type Function Conveyor elevation Conveyor swing Left cutting motor current Right cutting motor current Gathering head elevation Hydraulic reservoir level , Hydraulic reservoir pressure ». Hydraulic solenoids current Input line voltage Main hydraulic return flow Left tram motor current Right tram motor current Gathering head conveyor motor current. Pump motor current Pilot filter pressure Main pump flow Pilot pump flow Pilot pump pressure Main pump pressure. Pilot pump temperature Main pump temperature Shear elevation Left tram distance Right tram distance Stabilizer elevation Stabilizer pressure not used. Units 1.. 2.. 3.. 4.. 5., 6., 7.. 8.. 9.. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26, 3B31-03 3B31-00 3B31-03 3B31-03 3B31-00 3B32-01 3B 16-01 3B31-03 3B32-02 3B31-03 3B31-03 3B31-03 3B31-03 3B31-03 3B 16-01 3B31-01 3B31-01 3B31-01 3B31-01 3B31-01 3B31-01 3B31-00 3B31-03 3B31-03 3B31-03 3B31-03 0°-20°. 0°-95°. 0-400 A. 0-400 A. 0°-25''. 0-16 in. 0-25 psia. 0-5 A. 0-750 V. 0-85 gpm. 0-100 A. 0-100 A. 0-100 A. 0-200 A. 0-50 psia. 0-30 gpm. 0-20 gpm. 0-2,000 psi. 0-4,000 psi. 50°-250° F. 50°-250° F. 0°-50°. 0°-220.5 ft. 0°-220.5 ft. 0°-40°. 0-5,000 psi. Modules 27 through 32 are been determined,^ via underground field measurements, that military standard MIL-STD-810B for tracked vehicles best represents the vibration environment for electronic components mounted on under- ground coal mining equipment. With the vibration environment in mind, a computer ^Bartholomae, R. C, B. S. Murray, and R. Madden. Vibration Qualification of Electronic Instrumentation for Under- ground Coal Mining Machinery. BuMines IC 8883, 1982, 10 pp. chassis was constructed and then tested on a shaker table. The results identified the vibrational frequencies of the chassis. Knowing the mining machine and the computer chassis vibrational characteristics, a special set of soft vibration mounts with mechanical stops for shock suppression (Stock Drive Pro- ducts, model 10z38-0507) were procured for mounting the computer chassis on the mining machine. Their use minimized the computer chassis vibration. TABLE 2. - Digital I-O channel assignments Module Input (0DC5Q) 1.1 1.2 1.3 1.4 2.1 2.2 2.3 2.4 3.1 3.2 3.3 3.4 4.1 4.2 4.3 4.4 5.1 5.2 5.3 Function Module Input (0DC5Q) — Con. 5.4 , 6.1 6.2 , 6.3 6.4 , 7.1 7.2 , 7.3 7.4 8.1 8.2 8.3 8.4 Output (IDC5Q): 9.1 9.2 9.3..... 9.4 Function Conveyor elevation up. Conveyor elevation down. Conveyor swing right. Conveyor swing left. Control safety latch. Gathering head down. Gathering head up. Drum extension in. Right tram slow. Left tram slow. Right tram reverse. Left tram reverse. Right tram forward. Left tram forward. Tram fast. Drum extension out. Stabilizer jack up. Stabilizer jack down. Gathering head extension in. Gathering head extension out. Not used. Conveyor reverse. Shear up. Shear down. Cutting control. Pump run control. Power control relay. Conveyor forward. Not used. Do. Do. Do. Pressure switch 10- ym filter (16 psi). Pressure switch 3-ym filter (16 psi). Pressure switch 10- \im filter (35 psi). Pressure switch 3- ym filter (35 psi). NOTE. — The remainder of the 96 1-0 ports are presently unused. APPLICATION SOFTWARE MODES OF OPERATION The applications created for TAMME are identified as modes of operation includ- ing the system diagnostics mode, the sys- tem exerciser mode, closed loop test mode, the browser mode, and the scripting mode. Each of these modes of operation and associated piece of software permit the system operator to perform some series of tests or functions. A brief description for each of the modes of operation follows. System Diagnostics Mode This mode was used only in the develop- ment process and is no longer active in the system. It provided the initial checkout of hardware, and insured that all devices were connected properly. It was left in the system for future use. System Exerciser Mode Each of the functions on the Joy 16 CM machine normally controlled by the machine operator can be operated using this open loop mode of test. Each of the appendages can be turned on for a length of time as selected by the user. No position feedback on the con- trolled appendage it used. This mode was created to obtain appendage control characteristics. Closed Loop Mode Several of the Joy 16 CM machine ap- pendages have sensors to validate their position. Use of this mode lets the researcher operate the appendage under closed loop control. Characteristics such as overshoot due to gear backlash, hydraulic system response times, and other machine control variables can be analyzed using this mode of operation. Browser Mode Provides the operator with a quick look at the present analog voltage outputs of all of the sensors attached to the TAMME conditioning modules. Although mainly used for situation diagnostics, it can be used for more complex machine analysis. Scripting Mode An operator can use this software to create a complete mining cycle script by using a menu to select and then chain together several machine functions. Once a complete script is formed, it can be executed by entry of a single keystroke on the operator terminal. Each of the entries in the script will execute sequentially and will continue to the end unless terminated by, the user. SYSTEM INTEGRITY SOFTWARE System Confidence Tests The system confidence tests (SCT) soft- ware is resident in the firmware of the CPU board. The SCT is activated on powerup. It tests the CPU board, its memory, its interrupts, and most of the peripheral hardware. The results of the SCT are displayed on the local terminal. If no errors are detected, the operator continues with the normal powerup sequence. However, if errors are de- tected, the tests identify a possible fault and the computer executes the moni- tor program. Monitor The monitor is a primary software application, resident in the firmware of the CPU board. It contains a collection of simple programs that provide file loading and diagnostic capabilities^ TAMME Initialization Initialization begins with plugging a bubble memory cartridge, containing the applications and the operating system, into TAMME. A terminal set at 9600 baud must be attached to TAMME 's local user port. Power is applied first to the min- ing machine and then to the TAMME chas- sis. Shortly, thereafter, the diagnostic software SCT begins testing of the CPU and attached hardware. If all systems check okay, the operator can load the operating system by typing b. This action puts the system into the human interface level of the operating system (fig. 2). Selection of the applications software is made at the human interface level. The application software package created for the Joy 16 CM machine is called TAMME. Typing TAMME into the keyboard starts the application. The first part of TAMME creates a special software task called the watchdog timer, which is a software implemented safety device. Next, two user I-O jobs are created that provide menu-driven inter- faces to a local terminal user and a remote terminal user. The system is now ready to perform any of the experiments as selected from the menus. Watchdog Timer This software task exists within the software application called TAMME, which is stored in the bubble memory cartridge. It is activated with the TAMME task and runs simultaneously with it. Its algo- rithm provides a CPU activity signal to external hardware. As long as the watch- dog timer is executing, a particular bit on a digital output port is being tog- geled. If the CPU experiences some failure, the watchdog timer task will stop and its output signal quits toggl- ing. External hardware, attached to the watchdog timer port, expects to see a toggling signal. When the toggling quits, power to computer control 10 circuitry is removed, thereby disabling the Joy 16 CM mining machine. This application was primarily instituted as a safety device because of the potential danger that an out-of-control, 50-st min- ing machine presents. LOCAL USER OPERATION The local user is the primary operator of the system. All of its features are provided through a menu-driven interface. The operator simply selects a function, provides parameters, and initiates a process. This section is a descriptive tutorial on the capabilities of the TAMME system. The information is presented this way because its the best method to detail the individual processes. Figure 5 is a menu flowchart detailing the menu operation. MENU 1 ***************************************** System Exerciser Mode 1. system diagnostics 2. system exerciser 3. closed loop tests 4. browser mode 5. scripting mode 6. exit enter (1-6) -> ********* *********^* *************** ****** System Exerciser Mode The system exerciser permits the opera- tor to test all controllable appendages on the machine without involving the use of any feedback sensor or other position determining devices. The machine append- ages are called primitives and are grouped into the types of control they provide. They include the latching prim- itives and momentary primitives. The latching primitives are appendages on the machine that are designed to be turned on or off for the duration of some part of a mining cycle. The momentary primitives are appendages that are used in short spurts during mining cycles. Testing of a primitive is done by first selecting a primitive type, and then entering an execution parameter. The selected appendage will then move in respect to the execution parameter. When the operator selects the system exerciser mode of operation, menu 2 is displayed. Here, the type of primitive function is selected. MENU 2 ***************************************** System Exerciser 1. latching primitives 2. momentary primitives enter (1-2) -> ***************************************** Latching Primitives The latching primitives are a group of four machine-controllable functions that are designed to be latched on or off for the duration of a mining cycle. The latching primitive menu (menu 3) comes up first with the present status and then with a selection of control. As the operator selects an item he or she is prompted with menu 4. Exiting menu 4 causes the Joy 16 CM to perform the selected operation. MENU 3 ***************************************** Latching Primitives Present Status conveyor forward off pump run control off control power relay off cutting motor control off Latching Primitives Menu 1. conveyor forward 2. pump run control 3. control power relay 4. cutting motor control 5. turn off all latching primitives 6. exit enter (1-6) -> ***************************************** 11 System exerciser — Closed loop mode — -Latching primitives -Momentary primitives -Control table- -Simulated machine table- -Hysteresis table- -Execution mode- -Target -Requested ramp rate -Maximum target -Control ramp rate -Lag time -Ex_out -Ex_in -Dep_out -Dep_in -Machine data-full speed -Machine data-requested ramp rate -Simulated machine-full speed -Simulated machine-requested ramp rate Browser mode- Scripting mode 1 -Read a script I [-Write a script I I -Act out a script FIGURE 5.— Menu flowchart. MENU 4 ***************************************** conveyor forward 1 to turn on 2 to turn off enter (1-2) -> ***************************************** Momentary Primitives The system exerciser menu (menu 2), item 2, provides control of the momentary primitives on the Joy 16 CM machine. The momentary primitives are appendages or other control devices that are designed to work intermittently during a mining cycle. Menu 5 provides the complete selection of available primitives. As a primitive is selected, the operator is asked to enter the amount of time that the primitive is to be executed. Entries from 0.01 to 99.99 s are permitted. Upon successful execution of a momentary prim- itive, an okay message is shown. Any error messages shown will Indicate reasons for failures to complete a timed target value. 12 MENU 5 ***************************************************************************** Momentary Primitives Menu 1-conveyor elevation up 4-conveyor swing left 7-gathering head up 10-left tram slow 13-right tram forward 16-drum extension out 19-gathering head ext in 22-shear up 24-tram lo speed forward 27-tram hi speed reverse 30-tram reverse turn rt 33-pivot left 2-conveyor elevation down 5-control safety latch 8-drum extension in 11-right tram reverse 14-left tram forward 17-stab jack up 20-gathering head ext out 23-shear down 25-tram high speed forward 28-tram forward turn right 31-tram reverse turn left 34-return to main menu 3-conveyor swing right 6-gathering head down 9-right tram slow 12-left tram reverse 15-fast tram 18-stab jack down 2 1-conveyor reverse 26-tram lo speed reverse 29-tram forward turn It 32-pivot right enter (1-34) -> ************************************************************************************* Closed Loop Test When element 3 of the main menu (menu 1) is selected, the operator is presented a menu (The closed loop control menu — menu 6) through which a machine appendage can be tested for accurate positioning when using sensor feedback for valida- tion. In the tests, embedded software algorithms compensate for machine control variables such as gear backlash and hydraulic response times. The primary control algorithm is called the servo. In servo, a requested target value is pursued by activating the appropriate machine appendage and monitoring the out- put from the sensor attached to the appendage. As the machine appendage closes in on the requested target, then the algorithm deactivates the appendage control, which indicates the requested target was reached. Operation of this mode begins by requesting the operator to fill in the tables provided by items 1, 2, and 3 of menu 6. Then the operator goes to the execution mode to select a primitive to test. The various tables and menu items are described in the following sections. MENU 6 ***************************************** Closed Loop Control Menu 1. control table 2. simulation table 3. hysteresis table 4. execution mode 5. exit enter (1-5) -> ***************************************** Control Table The first table the operator must fill in is the control table (see menu 7). This table identifies each of the machine primitives and shows operator changeable parameters including a target, a re- quested ramp rate, and a maximum target. These operator changeable items are described in the following sections. 13 MENU 7 A ************************************************************************* Closed Loop Control Table Function 1 -conveyor 2-conveyor swing 3-shear 4-stab jack 5-gathering head Function 6 -tram slow 7-tram fast 8-tram reverse slow 9-tram reverse fast Function 10-pivot left 11-pivot right 12-tram reverse left 13-tram reverse right 14-tram forward left 15-tram forward right select an operation 1-update 2-exit enter (1-2) -> ************************************************************************************* Target(deg) Req ramp rate(deg/sec) Max target(deg) 1.23 4.7 20 2.45 5 95 24.66 3.1 45 6.90 12.1 25 10 1.8 24 Target(feet) Max target(feet) 11.3 200 33 150 121 140 122 140 Target(deg) 360 45 360 22 180 34 180 50 270 23 270 12 Target The target value is a position in degrees or feet that the operator wants the primitive on the machine to achieve. The target value is actually the scaled output from a sensor or collection of sensors associated with a particular primitive. Presently, only primitives 1 through 5 use sensors to determine position. Requested Ramp Rate This parameter is associated only with the first five primitives. Its value is given by operator input, in degrees per second. The requested ramp rate is only used when the operator requires a primitive to operate at less than full speed, and then the speed is determined by the values supplied in this table item. The selection of using a requested ramp rate or full speed is provided through menu 10 (type of execution menu). Maximum Target The value entered into this table item, is used by the software to set the maxi- mum allowable limit for a target, as determined by the scaled sensor output. This number is the maximum output that a sensor can provide under normal operating conditions. If this number is ever exceeded, the computer would indicate a possible hardware failure in the system. As a closed loop test is executed, values 14 from menu 7 task. are supplied to a software Closed Loop Test, Execution Mode, Algo- rithm Description The algorithms created for the execu- tion mode are identified in figure 6. The operator begins execution by select- ing a primitive; from then on, the pro- cess is automatic. There are five tasks that provide the closed loop algorithm. Each task is an Independent piece of software that runs concurrently with each of the other tasks. The purpose for each task is described in the following sections. Execute Execute is created as soon as the oper- ator selects a primitive function. The first step it performs is to collect data for the selected primitive from the appropriate data tables. Next, execute creates a second task called spawner. Then it goes into a sleep state where it waits for one of two possible occur- rences; one, the operator interrupts the process; or two, the computer halts the process when the primitive achieves a target within the hysteresis band. Spawner The spawner task's purpose is to create the entire closed loop cycle. First the FIGURE 6.— Closed loop test algorithm. analog data task, then the servo task, and, finally, the ramper task is created. Spawner provides each of the tasks with primitive specific initialization data. After these tasks are created, Spawner dies. Analog Data This task continuously provides primi- tive specific, conditioned sensor data, as requested. Servo The servo algorithm begins by waiting for a message for a target value from the ramper to which a particular primitive is supposed to achieve. As soon as a target value is received, the present position of the primitive is determined, and is compared to the target value. If the primitive position is within the hystere- sis boundaries of the target, then no action is taken. However, if the primi- tive position is outside the hysteresis boundaries of the target, then action is taken to move the primitive to the appropriate position. Ramper Ramper is a software task that outputs to the servo, varying numbers at a con- stant rate that represent target values. The numbers increase or decrease towards some final number that represents the final target. When the final target number is achieved, it is continuously output at a constant rate until the closed loop process is halted. Simulated Machine Operation Item 2 (simulation table) from the closed loop control menu (menu 6) pro- vides a simulated machine, mode of opera- tion, and is used only as a computer debugging tool, and is not used to con- trol the mining machine. In fact, when this mode is used, the computer should not be connected to the mining machine. The numbers entered into the simulation table are used to cause a digital- to-analog (D-A) converter to simulate the 15 output of a particular sensor attached to a particular moving appendage on the min- ing machine. The creation of this mode was done primarily to permit the system developers to test software algorithms without having to use a 50-st mining machine to debug the software. Use of this mode requires that the outputs of the appropriate channels of a D-A card be attached to the appropriate channels of the analog-to-digital (A-D) converter card. The table provided to the user is shown in menu 8. Descriptions of the operator changeable parameters for items in menu 8 follow. Ctrl Ramp Rate The numbers entered for each of the machine primitives are the actual rate at which the analog signal will change for a particular channel of the D-A card. Lag time The operator-entered number represents a machine constant for gear backlash and hydraulic system delays. Hysteresis Table (See Menu 9) This table (displayed when item 3 of menu 6 is selected) presents operator changeable parameters that take into account the inaccuracies associated with controlling machine appendages on the Joy 16 CM mining machine. The parameters Ex_ out, Ex_in, Dep_out and Dep_in are posi- tions in space about a target to which the appendage is to move. Use of these parameters, in the closed loop mode of operation, eliminate instabilities inher- ent in machine control environments. A MENU 8 ****************************************************************************** Simulated Machine Operation Function 1 -conveyor up 2-conveyor down 3 -conveyor swing up 4-conveyor swing down 5-shear up 6-shear down 7 -stab jack up 8 -stab jack down 9-gathering head up 10-gathering head down Function 11-tram slow 12-tram fast 13-tram reverse slow 14-tram reverse fast 15-pivot left 16-pivot right 17-tram reverse left 18-tram reverse right 19-tram forward left 20-tram forward right Select an operation 1-update 2-exit enter (1-2) -> ************************************************************************************* Ctrl Ramp Rate(deg/sec) 1.2 Lag time(sec) 1 2.5 1.5 5.0 1.6 3.4 2.1 3.4 0.3 2.1 1.5 3.4 0.6 2.9 1.2 5.9 0.9 2.9 0.8 Ctrl Ramp Rate(f eet/sec) 1.4 Lag time(sec) 3.2 3.2 1.9 4.3 1.2 6.8 0.7 19.1 0.8 19.1 0.5 9.8 2.4 2.4 0.6 15.1 0.9 20 2.3 16 more detailed description of these param- eters will be subsequently published.^ When a closed loop cycle begins, values are taken from this table and are used to determine if the primitive is within a target window. MENU 9 ***************************************** Hysteresis Levels Table (all parameters are in degrees) Primitive Ex_out Ex_in Dep_out Dep_in 1-conveyor 1.6 1.3 1.45 1.2 2-conveyor swing 4.5 3.9 4.5 4.6 3-shear 2.7 0.4 2.9 0.4 4-stab jack 4.0 2.3 4.0 1.6 5-gathering head 2.9 2.2 2.9 2.2 Select an operation 1-update 2-exit enter (1-2) -> ***************************************** Execution Mode This is a working part of menu 6. From here, machine cycles are executed based on parameters entered in the tables listed in the closed loop control menu. Entry into this mode begins as shown in menu 10. From this menu, there a four selectable types of execution. A de- scription for each is provided in the following text. MENU 10 ***************************************** Type of Execution 1-machine data, full speed 2-machine data, requested ramp rate 3-simulated machine data, full speed 4-simulated machine data, requested ramp rate 5-exit this mode enter (1-5) -> ***************************************** "For further information, contact John Sammarco, Pittsburgh Research Center, Bureau of Mines, Pittsburgh, PA. Machine Data-Full Speed This mode of operation causes a selected machine primitive to move from its present position, as determined by sensor input, to a particular target as set in the closed loop control table (menu 7) and as measured by sensor input. The machine primitive will move at the maximum speed possible, limited only by the physical characteristics of the machine. Machine Data-Requested Ramp Rate This mode of operation causes a selected machine primitive to move from its present position, as determined by sensor input, to a particular target as set in the closed loop control table (menu 7) and as measured by sensor input. The machine primitive will move at a software controlled ramp rate as deter- mined by the Req_Ramp_Rate as input by the operator. Simulated Machine Data-Full Speed This mode of operation causes a selected computer output port to turn on and stay on until the software has con- cluded that a target was reached as determined by a simulated sensor input. The speed of execution is a measurement of the maximum response that can be expected from this set of hardware and software. Simulated Machine Data-Requested Ramp Rate This mode of operation causes a selected computer output port to cycle on and off at a software controlled ramp rate, until the software has concluded that a target was reached, as determined by a simulated sensor input. This cycle provides a base for testing closed loop control software algorithms. After the mode of execution is selected, the operator selects the primi- tive he or she wishes to execute from menu 11. 17 MENU 11 ***************************************** Closed Loop Control Selector 1 -conveyor 2-conveyor swing 3-shear 4-stab jack 5-gathering head 6 -exit select a primitive to execute (1-6) -> ***************************************** Browser Mode This mode is item 4 as selected from the main menu (menu 1). It gives the local operator a complete, instantaneous output from every sensor presently con- nected to the A-D converter card. The local terminal output is shown in menu 12. MENU 12 ***************************************** Browser Mode Output chan = 00.00 chan 1 = 00.00 chan 2 = 00.00 chan 3 = 00.00 chan 4 = 00.00 chan 5 = 00.00 chan 6 = 00.00 chan 7 = 00.00 chan 8 = 00.00 chan 9 = 00.00 chan 10 = 00.00 chan 11 ^ 00.00 chan 12 = 00.00 chan 13 = 00.00 chan 14 = 00.00 chan 15 = 00.00 chan 16 = 00.00 chan 17 = 00.00 chan 18 = 00.00 chan 19 = 00.00 chan 20 = 00.00 chan 21 = 00.00 chan 22 = 00.00 chan 23 = 00.00 chan 24 = 00.00 chan 25 = 00.00 chan 26 = 00.00 chan 27 = 00.00 chan 28 = 00.00 chan 29 = 00.00 chan 30 = 00.00 chan 31 = 00.00 ***************************************** Scripting Mode The scripting mode is a software appli- cation that permits the user to chain together a series of machine movements that can be executed with a single key- stroke. As in all of the TAMME applica- tions, it is menu driven. The operator activates it from the main menu (menu 1) by selecting item 5. The first screen (menu 13), displays three applications, which are described in the following section. MENU 13 ft**************************************** Scripting Mode Menu 1-read a script 2-write a script 3-act out a script 4-quit enter (1-4) -> ***************************************** Read a Script This mode provides a directory of available scripts. Generally, the names of the scripts will be descriptive of the process to be performed. Menu 14 shows the contents of the setup script. Each element is numbered and the execution parameter is identified. The script, when executed, will begin with line num- ber 1 and end with the last line number shown. Modification of a script must be done using the write a script Mode. Write a Script Mode There are nine possible scripts that can be created. Each has a built-in default identifier, but these can be changed as required as shown in menu 15. Creation of a script is as simple as answering a series of questions at the prompts provided (a prompt is represented by ->). Menus 16 through 18 show the operators interactions in the process of making or changing a script. 18 MENU 14 ***************************************** Script Directory MENU 16 ***************************************** Script Directory - setup 1 - tramtoface 2 - findstart 3 - firstcut 4 - produce 5 - fillshuttle 6 - backout 7 - movenew 8 - shutdown 9 - exit Select a script to show (0-9) ->0 Script no. 1 Line # primitive 1 control power relay 2 pump run control 3 control power relay 4 tram lo speed forward 5 left tram slow 6 drum extension out 7 pivot right 8 turn off all latches ***************************************** MENU 15 ***************************************** Script Directory - setup 1 - tramtoface 2 - findstart 3 - firstcut 4 - produce 5 - fillshuttle 6 - backout 7 - movenew 8 - shutdown 9 - exit Select a script name to change (0-9) ->6 Enter the new name (maximum of 8 letters) ->backof f ***************************************** - setup 1 - tramtoface 2 - findstart 3 - firstcut 4 - produce 5 - fillshuttle 6 - backout 7 - movenew 8 - shutdown 9 - exit Select a script to change (0-9) ->1 Sc ript no. 1 execution Li ne # primitive execution parameter parameter on 1 control power relay on on 2 pump run control on on 3 control power relay on 12.45 4 tram lo speed forward 12.45 4.5 5 left tram slow 4.5 2.3 6 drum extension out 2.3 5.6 7 pivot right 5.6 on 8 turn off all latches on Script can be 20 lines long Enter 21 to exit Select a line in the script to change (l-21)->6 ***************************************** MENU 17 ***************************************** The script ends at the first disabled line. Enter 1 to enable this line Enter 2 to disable this line ->1 Do you want a new primitive. Enter (y-n) ->y ***************************************** 19 MENU 18 Select a primitive Momentary Primitives 1-conveyor elevation up 2-conveyor swing right 5-conveyor reverse 6 -shear up 8-stab jack up 10-gathering head up 12-gathering head ext in 14-drum ext in 16-right tram slow 18-fast tram 19-right tram forward 21-right tram reverse 23-tram lo speed forward 25-tram lo speed reverse 27-tram forward turn right 29-tram reverse turn right 31-pivot left Latching Primitives 33-conveyor forward 35-control power relay 37-turn off all latches select one ->22 2-conveyor elevation down 4-conveyor swing left 7-shear down 9-stab jack down 11-gathering head down 13-gathering head ext out 15-drum ext out 17-left tram slow 20-left tram reverse 22-left tram reverse 24-tram high speed forward 26-tram high speed reverse 28-tram forward turn left 30-tram reverse turn left 32-pivot left 34-pump run control 36-cutting motor control 38-exit For timed primitives enter seconds (0.01 to 99.99) For latching primitives enter (1) for on and (2) for off enter here ->1.45 Remote User Operation A remote user port is provided by TAMME through its operating system and hardware (fig. 1). This is a serial port than can be used in a number of ways. A dumb terminal can be attached and operate the system. A personal computer (PC) can be attached, and then operate the system using terminal emulation software. A modem can be attached, which will allow any number of remote computers to gain access to TAMME using standard modem communication software. Remote operation has been confirmed using the following machines: Symbolics 3600, Corona Data System PC, and Intel 310. Since this is a multitasking, multiuser system, both the local user and the remote user can simultaneously interact with the Joy 16 CM. One user can be operating the machine, and another can be doing diagnostics. Or in a carefully orchestrated experiment, both users can run the machine. The range of possibili- ties are large but careful planning is crucial. 20 So far, the interactions through the remote port have been accomplished through menu-driven interfaces. The menu items are a limited set of what is avail- able to the local user. There is, how- ever, a special function now being built SUMMARY into the menu, that allows the remote port to communicate in a computer- to-coraputer fashion, rather than in a human-to-coraputer fashion, such as using menus. It employs a simple protocol. The first step towards making a Joy 16 CM mining machine is now complete. The fundamental performance characteristics, under computer control, have been deter- mined. The next areas of activity will be to experiment with a variety of devices that will ultimately give the machine knowledge of its position in respect to the coal, the roof, and the general work area. Additionally, experi- ments will be performed in the areas of machine health, fault diagnosis, and interaction with mining machine support equipment. All of these experiments will begin as independent entities. As they evolve and produce practical hardware and software, they will be integrated within the TAMME system. To facilitate this evolution, TAMME is presently being enhanced by connection of a high-speed, multitasking, distributed, microcontrol- ler-based network. TAMME will act as the master in this network. The newly devel- oped application devices, hardware, and software will be attached to a node in the network, as shown in figure 7 (a node is one microprocessor, which has built-in communication and intelligent control algorithms). Data transferred between a node and TAMME will be very high level. This mode of operation will relieve TAMME of detail work and permit it to concen- trate on its main function being process orchestrator. The Bureau has developed a tool that provides access to mining machines, through which researchers can perform experiments, toward the goals of in- creased production and operator safety. Software algorithms provided by TAMME allow experimenters to completely define the control characteristics of a machine and then implement these characteristics in higher level software programs. With these higher level programs the TAMME system demonstrated control accuracy that is far superior to what a human operator can provide. Remote user operation of machine functions proves that other com- puters can be added to the system for additional system enhancement. Although TAMME was constructed to be a research tool, its flexible design makes it easily reconf igurable to a production tool. In fact, some of the software algorithms already created could be used for production without any changes. And BITBUS NETWORK FIGURE 7.-TAMME and bitbus network. even though the hardware was set up for a Joy 16 CM machine, its modular I-O con- figuration can be quickly adapted to most any machine by simply changing a plug-in module. The development and documentation of this system is provided in hopes of mak- ing it easy for others to pursue the goals of making coal mining more economi- cal and safer. INT.-BU.OF MINES,PGH.,PA. 28769 U.S. GOVERNMENT PRINTING OFFICE: 1988-0-547-389 oc LU >■ 2 a. UJ QC o Q. a. O _i < o UJ >. « ^ ^ *" .2 Q • ^ ■at a5 T3 (0 (0 .i • > § 8 1^ * 5 S (0 UJ z (0 3 » E .2 "-ID — «^ 1? CO CO UJ S « o> o — 53S •s£ 1 eg in 3 m RIV/I twis Plea mail c w t is OC 1 < Q. -1 < o FORP » do no iterial. myour 18 (0 V) ^o c« c ■r- X u. t SeS SI CD -J 2 o o o m d JO CO O i UJ Q. . 0) ID £0 O Cl Q. > "^ .40^ . ■AT o^Zj" ^ Iff * «!' ''^, oT ^-./ * %.^" --^ \v .. ^-^ »'"' A° V "^ ^-r^ .* ••^-. **.„,/ Aw/A. >.,.■ .Ho^ . %.^^ vpC,- *' ^* "'Sj^'- \»./ .-if^J.". v,<.« /JK\ v./ -'^ c, \r V'^^ .40^ ., iOv!,, •^o^ ^^ / ^^ . ^•^ V.<=,'^^ r- '-e^-o^ o*, tf^ *e,o' .^> ^-^ °^ %.^^ ''J'..\'^''<^^ ^^.^*-^-*fO' ^^^'*.^'\^^^ ^^.^*-^-*^o' V" • "' *^ •^^••"* ^f HECKMAN I BINDERY INC. | /^^ SEP 89 ^^ N. 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