Naked Science Forum
Non Life Sciences => Technology => Topic started by: cstrange on 25/10/2019 07:01:50
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Researching for a science project and really can’t break through this idea. There are multiple methods of tracking speed of an object fro point a to b, but can’t figure out how to miss these variables.
Imagine a baseball pitching machine at home plate (or just a phone on a tripod). Then imagine a person at 1st base with a sensor (or something) on their glove. Once the base station says GO (via an audio cue, or actual baseball being launched, or another signal from a device), the player will move either right or left (pending cue) and attempt to reach point that ball would travel. So let’s say that machine lines up to send a ball 10 ft either right or left. Once signal/Go is given by base station, how far can player move right or left before ball (or imaginary ball) would cross the plane in which they are running?
Base Station
/ I \
/ I \
/ I \
/ I \
/ I \
/ <————- Person ————> \
You can measure speed easily, by radar, infrared, or a simple device where player triggers time at start and finish. I have to triangulate the start, static speed of object, variable speed of person, etc.
Any help on what type of technology I could/would use would be appreciated. I could build an app to process the data, but an at a loss of how to easily collect this data.
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I can't follow thru what you are describing. It will depend on what you are trying to measure. Measuring the speed of a ball, will be different than measuring speed of a man.
There are many high tech options for accurate results at low cost. Everything from pen lasers to piezo impact sensors. And wifi networks.
A PIC or Arduino can do marvelous things today.
And one can always go the low tech way, with string and stop watches. Or even a microphone for a sensor.
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I can't follow thru what you are describing. It will depend on what you are trying to measure. Measuring the speed of a ball, will be different than measuring speed of a man.
Thank you. As mentioned above, Once signal/Go is given by base station, how far / fast can player move right or left before ball (or imaginary ball) would cross the plane in which they are running?
I am trying to measure the quickness of a player (and not just the player...but his hand) to get to a specific point as soon as ball is hit (or signal is given).
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You can start with a calculation. Initial response time to consciously process an audible signal is about 0.1 seconds (interestingly, it's quicker than a visual response). Acceleration depends on the power/mass ratio of the player or the part that you are interested in (arm and bat) and can be assumed continuous over 10 ft from a standing start. However (see below) you may be surprised by the result.
There are plenty of video tracking systems around. One of the simplest is the tennis line monitor but it doesn't measure speed or trajectory. https://www.hawkeyeinnovations.com/products/ball-tracking is a much more sophisticated device that extrapolates the free trajectory of a ball that has been intercepted, to predict where it would have gone if the batsman hadn't been in the way - developed for cricket, where this matters.
What is interesting is the finding that a cricketer cannot actually move quickly enough to hit the ball! It turns out that the contest between a Test-level bowler and batsman is one of experience and anticipation, not evaluating the actual flight of the ball. It is quite likely that a batsman will fare badly against a randomised bowling machine because he has no clues from the bowler's eyes, grip, or run-up, as to where the ball is likely to pitch and turn, but it was clear from the analysis of many hours of video footage of Ian Botham that he had committed to play each particular stroke before the ball left the bowler's hand. Unlike baseball, even a slow bowler can beat a good batsman because however long the ball takes to travel, its bounce is not entirely predictable, so only the last milliseconds matter, and again it is the bowler's "tells" that determine the expert batsman's approach. Similar considerations apply to a soccer goalkeeper facing a penalty kick: assuming the kicker is reasonably expert, the ball will go where his eyes were last directed just before he looked down to make contact. By the time the ball starts moving, it's too late to decide which way to jump to intercept it.
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"Once signal/Go is given by base station, how far / fast can player move right or left before ball (or imaginary ball) would cross the plane in which they are running? "
"I am trying to measure the quickness of a player (and not just the player...but his hand) to get to a specific point as soon as ball is hit (or signal is given)."
I have no idea of what that means. Motion has several characteristics. Motion has displacement. There are two types of displacements(length). Motion has speed and/or velocity. Motion has direction. And motion has time. And motion takes acceleration.
Which characteristic of motion would you like to measure? And what do you want to reference that measurement to?
What event starts the measurement and what event stops the measurement?