A Performance Analysis System for the Sport of Bowling

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$Course Syllabus - Penn State Harrisburg Math/Computer Sciences ...$

$A Simulator for the MARIE Architecture - Penn State Harrisburg Math ...$

almost 27 times between the foul line and the head pin. The ball would also have to be thrown at over 25 miles an hour for the rotational rate to reach 1000 rpms. Those values are extreme, but they allow an upper limit of 1000 rpms (16.7 Hz) to be set as the maximum angular velocity. The vast majority of bowling establishments utilize fluorescent lighting. Preliminary testing with the TSL251 revealed that the sensor is responsive enough to detect the 120 Hz optical ripple of the overhead fluorescent lights. This ACinduced ripple becomes part of the ambient light level, and could cause a problem, since the pseudo-sinusoidal target waveform must be extracted from the ambient light. However, the AC ripple is confined to a narrow band at 120 Hz, while the desired fundamental waveform is of a much lower frequency. Sampling the waveform at a frequency less than twice the 120 Hz ripple could result in "aliasing" the 120 Hz content down into the frequencies of interest (< 20 Hz). And sampling at a frequency other than a harmonic multiple of 120 Hz could introduce harmonic variations into the raw waveform that the module must then deal with, since it certainly won't have the processing capabilities to digitally filter the data. Sampling at a harmonic multiple of 120 Hz, such as 240 Hz, and storing the average of two consecutive samples (yielding a net 120 Hz data rate), averages out the AC ripple. The frequency of the AC ripple exceeds the target waveform by at least a factor of 7 (in the extreme case), but is actually closer to a factor of 15-20. Hence, the 120 Hz ripple should not interfere with data collection as long as an appropriate sample frequency is chosen, allowing for a resolution of at least 18°-24° of rotation. • Ball Speed: The vast majority of bowlers, even at the 200+ average level, generate an average ball speed of less than 20 mph (~30 fps). At 30 fps, it takes at least 2 seconds for the ball to travel from the foul line to the head pin (60 feet). For a ball speed of 30 fps and a net sampling frequency of 120 Hz, the ball travels 3" per sample period, good enough for 0.4% resolution over 60 feet. The vast majority of bowlers generate ball speeds greater than 10 mph (15 fps), especially those that average greater than 180. At 15 fps, it takes the ball 4 seconds to completely traverse the lane, or 480 samples at 120 Hz. • Data Memory: The hardware for the prototype SMARTDOT module was originally specified in January of 1993. At that time, the highest serial memory density readily available that was cheap enough to be practical was a 4096 bit (512 x 8) chip. This size memory is only big enough to capture a single roll of the ball. Affordable serial EEPROM memory density has increased dramatically since the SMARTDOT module prototype was designed, and the "Sample Memory" section details the implications of using a higher memory density. For the prototype module, ambient light sample data is produced faster than it can be consumed by single byte writes to the EEPROM. However, the EEPROM can handle 8 samples at a time, with a 10 msec max write time. A sample is produced every 8.333 msecs (120 Hz), and a circular sample buffer is used to accumulate 8 consecutive samples for writing to the EEPROM. The EEPROM performs the actual write in the background, after the data has been input to its write buffer. The 87C752 can continue collecting data in the circular buffer without having to wait for the EEPROM to finish storing the data. 20
2.6.3 Baud Rate The module communicates with the outside world through a serial IR interface using standard baud rates. A software UART had to be implemented for the SMARTDOT module, since the 87C752 does not have an on-board hardware UART. The 3.6864 MHz crystal supports both the 240 Hz sampling rate, and running the software UART at all of the standard baud rates up to 38400 baud. The rise/fall time of the TSL251 limits the module's reception rate to 600 baud, which is not a problem, since the module receives little information compared to what it must transmit. On the transmit (upload) side, the entire contents of memory (512 bytes) must be uploaded rapidly so as not to inconvenience the user. At the 38400 baud rate, the entire contents of memory can be uploaded in less than a second. 2.7 EMBEDDED SOFTWARE DESIGN AND OPERATION This section presents a detailed description of the SMARTDOT module's embedded software operation. The module's software architecture is shown in Figure 2-4, which diagrams the interrelation of the major software tasks, and their interaction with the interrupt service routines (ISR's). The following software description and the architecture diagram both make reference to flowcharts for the embedded tasks and interrupt service routines, which are included in Appendix A. The actual assembly code is thoroughly documented, and has been included in Appendix B. 2.7.1 Software Design Considerations Due to the cost and physical size constraints of the application, the SMARTDOT module relies on a relatively simple hardware design. The complexity of the module is contained within its embedded software and the efficient use of the microprocessor's on-board resources and peripherals. The 87C752 microcontroller has severe constraints on both its on-board program EPROM (2048 bytes) and RAM (64 bytes). The RAM space also includes the general-purpose registers, the bit addressable space, and any required stack space. Although 'C' compilers are available for the 87C752, they are notoriously spaceinefficient, and 'C' makes heavy use of the stack. Due to the limited sizes of the code and data spaces, the embedded software was implemented in Intel 51 assembly language, with careful attention paid to the maximum depth of procedure calls, and with minimal parameter passing via the stack. The required stack space has been held to 16 bytes, allowing for a call depth of four (two-byte return addresses and two additional bytes (usually ACC and PSW) PUSHed onto the stack for each call). The application is both event and interrupt driven, with pre-emptive, round robin multitasking used on a limited basis to implement task time-outs, sampling, and discrimination between "valid" waveforms, attempts to communicate, and spurious activations. Microprocessor interrupts are used for acquiring regular light waveform samples, for impact detection, for implementation of the software UART, and for keeping accurate track of time. Event driven (polled) tasks include detection of release and detection of the COMM Wand. Semaphores are used for task synchronization. 21
Page 1 and 2: The Pennsylvania State University T
Page 3 and 4: TABLE OF CONTENTS Section I: Introd
Page 5 and 6: LIST OF FIGURES Figure 2-1 SMARTDOT
Page 7 and 8: SECTION I: INTRODUCTION, BACKGROUND
Page 9 and 10: eceiver that stores, processes, and
Page 11 and 12: 1.3.2 Product Development Phase The
Page 13 and 14: SECTION II: COLLECTING THE DATA - T
Page 15 and 16: 2.2 Design Constraints The feasibil
Page 17 and 18: 2.3 SENSING REQUIREMENTS The module
Page 19 and 20: Pin Deck Light Foul Line Figure 2-2
Page 21 and 22: 2.4.1 Ambient Light Sensor The ambi
Page 23 and 24: 9 28 8 RST V CC V CC 5 6 hyst 7 3 +
Page 25: 2.6 HARDWARE/SOFTWARE INTERACTION D
Page 29 and 30: Configuration settings and the samp
Page 31 and 32: 2.7.5 The Ball is Rolling If the wa
Page 33 and 34: covered by the wand). When the modu
Page 35 and 36: 2.8.1 Detecting Release Detecting t
Page 37 and 38: Light Level 100 90 80 70 60 50 40 3
Page 39 and 40: By filtering the data, and then cou
Page 41 and 42: The 'F300x can write to any portion
Page 43 and 44: One possibility is to use a transfo
Page 45 and 46: 2.10 SUMMARY This portion of the re
Page 47 and 48: The ball's angular velocity increas
Page 49 and 50: Light Level 100 90 80 70 60 50 40 3
Page 51 and 52: the fundamental frequency has been
Page 53 and 54: Since the fundamental frequency and
Page 55 and 56: Figure 3-7: MASTER "Analysis" Scree
Page 57 and 58: known, the linear momentum (and thu
Page 59 and 60: In order to find the value for v 1
Page 61 and 62: 3.5 ASSUMPTIONS AND ERROR ANALYSIS
Page 63 and 64: 3.5.3 External Forces and Friction
Page 65 and 66: 3.6.1 Implementation and Performanc
Page 67 and 68: Figure 3-11a: Effects of Phase Shif
Page 69 and 70: 3.6.3 The "Perfect" Game to Analyze
Page 71 and 72: Since the change in angular velocit
Page 73 and 74: BIBLIOGRAPHY [1] United State Paten
Page 75 and 76: APPENDIX A - SMARTDOT MODULE EMBEDD
Page 77 and 78:
Appendix A: SMARTDOT Module Embedde
Page 79 and 80:
Page 81 and 82:
Page 83 and 84:
Page 85 and 86:
APPENDIX B - SMARTDOT MODULE SOURCE
Page 87 and 88:
Appendix C: SMARTDOT Module Command
Page 89 and 90:
Figure C-3 Appendix C: SMARTDOT Mod
Page 91 and 92:
APPENDIX E - 300 GAME MASTER SCREEN
Page 93 and 94:
Appendix E: 300 Game Analysis Frame
Page 95 and 96:
Page 97:
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A Performance Analysis System for the Sport of Bowling

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