Principle of operation

The cameras are triggered by any object that passes over the trigger sensor array.

Image processing will then detect if a flying or rolling golf ball was present in the captured frames

and determine the ball speed, path and launch angle and pass this on to the golf simulator system software

which in turn will calculate the ball's flight trajectory and launch the ball in the system.

The above image is a true live shot from the floor mounted vertical launch angle camera of a ball hit with a 7 iron.

The camera field of view is actually far greater than what is actually required

and captures the player (on the right), the projection screen (on the left) and the floor.

The blue border lines dictate the valid field of view

and the red line dictates the maximim ball height a ball will have to be considerd as a rolling ball or sculled shot.

Note the strong contrast between the background and the ball trace.

This is achieved by setting the camera gain high which amplifies the contrast.

The room is actually much lighter so you are not playing in the dark but the camera sees it as very dark due to the fast shutter speed.

The ball is illuminated by the overhead halogen lamps.

This is the basic floor layout for the 3 (or less) cameras.

The vertical launch camera can be mounted either on the left or right side of the enclosure adjacent to the trigger sensor array.

The overhead ball path camera should be mounted centered and just behind (away from screen, toward hitting mats) of the trigger sensor array.

Club track camera immediately above the tee in the sensor mat.

Putting can be made anywhere behind the 5ft/1.5m wide trigger sensor array.

All other shots should be made from the desired hitting mats.

Connecting the cameras to the PC and basic tests.

Cables and connectors:

The systems are supplied with a number of cables.

For the PX5 system these are:

2 USB camera cables with mini A to B connectors

5 10ft long USB extension cables.

1 15ft RCA camera trigger extension cable

1 15ft RCA trigger signal cable connected to the trigger array with dual outputs

1 4ft USB power cable connected to the trigger array

1 4ft USB cable connected to the sensor mat

Connect the cables as follows:

1. Connect a mini A to B USB cable to each camera

2. Connect one USB extension cable to the floor mounted Vcam camera USB cable to give a 14ft length

3. Connect two USB extension cables to the overhead Hcam camera USB cable to give a 24ft length

4. Connect one USB extension cable to the trigger array USB cable (not required if using a Line Scan camera)

5. Connect one USB extension cable to the sensor mat USB cable

6. Connect one of the trigger RCA signal output cables of the trigger array to the Vcam camera RCA connector (not required if using a Line Scan camera)

7. Connect the 15ft RCA extension cable to the other trigger signal cable of the trigger array and the other end to the Hcam camera RCA connector

Now connect all USB cable ends to the host PC.

When connecting the camera and sensor mat USB cables to the PC you might want to wait until the PC has installed the drivers and you get the "successfully installed" message from Windows

Note: When using muliple cameras, each camera must be connected to a seperate USB bus.

Mounting the cameras

The cameras should be mounted as shown in the above floor plan image for X,Y setups. The distance the floor camera is mounted away from the trigger end should be around 1.5 meters or 5ft.

However, you can mount closer if space is limited.

Once the cameras are mounted , connect the camera USB cables to available USB ports on your PC and the camera trigger cables to the trigger sensor array.

The cameras are supplied with sufficient length high quality USB and trigger cables. (30ft / 10 meter lengths)

Connecting and testing the camera trigger sensors. (not required if using a Line Scan camera. Go to Line Scan camera setup in this case)

The 4ft long sensor trigger array allows you to hit shots from anywhere behind the sensor array (ie from other simulated surfaces).

The unit has 3 cables connected to it. A USB cable and two trigger signal output RCA cables.

The USB cable is connected to any USB connector on your PC (it is only used to supply power to the trigger array).

The trigger output RCA cables are connected to the cameras.

When connected to the PC via the USB cable you will see 5 green lights (LEDs) which indicate that power is getting to all the 5 banks of sensors.

A 6th red LED at the far end indicates that a trigger signal has been generated.

When the overhead lamp is on this red light should normally be off and should only light up when an object passes over the sensors. You can test this by putting your foot over the sensors.

If the red light is constantly on then this indicates that the overhead lamp is not positioned correctly over the unit. Light from the overhead lamp should be reaching down to all the sensors.

Check that the beam is centered over the unit so that light reaches both ends of the trigger unit.

Testing that the trigger sensors are triggering the cameras

Faulting finding tip:

Camera's don't trigger with a ball but do when I pass a larger object over them like my club head, hand or foot.

The problem is caused by light from other lamps getting onto the trigger sensors.

The light from the trigger sensor array overhead lamp is the only light that should get onto those sensors.

If light from any other lamp gets onto the sensors then the shadow of the ball won't be dark enough to trigger the sensors.

Passing a larger object over the sensors will cause the sensors to trigger because a larger object (like your hand or foot) will block the light from all the lamps.

If this is the case but when hitting a ball over them doesn't result in a camera trigger then this is the cause of the problem.

Remedy:

1. Ensure that the sensors are embedded deep down in the flooring and only a slim cutout is exposing them.

2. Adjust the second ball tracking lamp so that it's light is not getting down onto the camera trigger sensors.

Lighting

Example setups for camera systems.

If you having problems cofiguring the various settings required for cameras and triggers try using the example setup/configuration files below.

Go here for camera trigger assembly instructions.

Go here to see enclosure layout diagram for camera systems.-

Testing the Cameras

Start the GSA Control Panel, select the appropriate camera options on in the Setup window i.e. Vertical Camera and/or Horizontal Camera - if you have these.

Use the presets PX2, PX5, CX3, CX5 etc shown at the top of the Setup Window and go to the Cameras window.

You should see that the camera(s) are detected and running.

Starting with camera 1, switch to Video Stream Mode.

If using multiple cameras, you should ensure that camera 1 is the floor mounted vertical launch camera.

If the view displayed for camera 1 is from the ball path or club track camera then you need to switch the cables to the USB ports.

Caution: Do not remove any camera USB cable while the camera is running. Before hand, shut down the GSA Golf Interface or ProX software.

Otherwise the camera engine may hang which may require re-booting the PC.

With the camera parameters and camera lens settings set to default, the view should be quite dark apart from the illuminated floor and any other objects out of the camera's valid FOV (field of view).

If this is not the case, then you must ensure that anything in the valid FOV is of a non reflective nature and dark.

ie the enclosure's background is dark and there are no other objects in the valid FOV causing reflections.

Camera Focus.

Ensure that the captured images are sharp and clear. Adjust the lens by screwing in or out if not.

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Adjusting the camera's view and setting the valid FOV borders.

Aim the camera so that both balls are as low as possible in the FOV. Place the balls at different distances if the ball nearest the camera is obscuring the further end ball.

An alternative - and actually more accurate - method of measuring ball path from the overhead camera is to set the Ball Launch Position.

If you place the Ball Launch position at the tee on the sensor mat (A) then the ball path will be measured from point A to point B.

If the Ball Launch Position is not set then the ball path will be neasured from point B to point C.

While this is OK for slower shots and putting, fast shots capture a much fainter ball trace and errors can occur. Notice that in the above screen shot that the

Raw ball path angle was only 1.56 degrees left when in actual fact it was 6.06 degrees left. We therefore recommend only using this method.

The above screen shot is of the new Ball Path camera panel showing the user adjustable ball launch position.

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Contrast too faint: image processing failed -------------------------------------Contrast sufficient: image processing correct

A common problem with the overhead camera is that the contrast between the synthetic grass flooring and the trace of a fast ball is insufficient and the trace isn't detected correctly.

A fast ball leaves a faint trace in the captured image and the synthetic grass flooring can reflect a lot of high level gray scale pixel reflections.

If you find difficulty adjusting the camera settings to compensate for this, a solution is to either cover the sensor trigger array with a non reflective 6 to 12 inch wide strip of carpet

or to mask off the area directly in front of the trigger sensors (4ft * 1ft) and spray paint with a mat black or dark green color.

Regarding the non-reflective carpet covering for the trigger casing:

It is essential that this material is non-reflective.

A recommended carpet is : Beaullieu of America - Type: Dayside Ebony, Product 6670-890 which is available at your local Home Depot store at around $4.00 a yard.

The carpeting should be cut to size in 2 strips and glued to the acrylic glass top of the trigger casing leaving a 1/4 inch space gap for the optical sensors.

The optical sensors are in line with the green LEDs.

This carpet is also very good for lining the inside of your enclosure. Especially for the wall opposite the vertical camera.

Thereafter adjust the valid FOV borders to only view this strip.

Camera window explained

These include:

1. Shutter speed (set according to lighting conditions) Default is 10,000 micro seconds.

2. Gain (set according to lighting conditions) default is 20db.

3. Min Gray Scale: When images are captured, software scanning routines will look for a golf ball in the image.

In order for the search to succeed there must be a good contrast between the background and the ball. Depending on lighting conditions this contrast may vary.

ie. the background may not be as dark and the ball not as bright. In any case, the ball must be distinctively brighter than anything else in the background.

You set this Minimum Gray Scale parameter to the minimum brightness (or gray level) of the ball. The value is from 0 (black) to 255 (white).

4. Ball min and max sizes: Depending on the distance the ball is from the camera, the image size of the ball will vary slightly.

The scanning routines use this value to help indentify a golf ball within the image.

5. Min Height, Max Height, Left end, Start border: These four parameters dictate the valid Field of View (FOV).

This is used to block out any parts of the image that may contain static objects in the camera's field of view (e.g. the floor) that may cause problems for the ball search scanning routines.

The scanning routines will only search within these borders of the image.

Max Height for a rolling ball: Set this red border line to the maximum height a rolling ball will have as seen through the camera's lens.

All balls found under this level will then be considered as a ball rolling on the ground.

6. Min Ball Speed: For the vertical launch monitor camera only, the ball must attain a minimum ball speed to pass within the cameras FOV in a straight trajectory line.

If the ball is hit with a slow speed (ie a chip) its trajectory will curve down within the cameras valid FOV and the calculated launch angle will not be correct.

7. Ball Launch Position: When set to the launch position - ie where you strike the ball - the launch angle will be calculated from this co-ordinate to the first co-ordinate in the ball trace.

8. Software Trigger: All cameras are triggered by an electrical signal sent to the camera when a ball or club head passes over one of the optical camera trigger sensors.

When testing and during setup you can simulate this hardware trigger by clicking this button.

9. Camera Assignments: The 4 radio buttons under each main Camera button allow you to assign the camera to a particular function.

The 4 functions are : Vcam - Vertical Launch Angle and ball speed, Hcam - Horizontal camera for ball path, Ccam - Club track camera and Bcam - ball spin and spin axisi tilt detection camera.

10. Video Trigger mode , Video Stream Mode: When a camera is in trigger mode, frames will only be captured (grabbed) with either a hardware or software trigger.

When in Video Stream mode, frames will be live captured and displayed at the standard frame rate in real time.

11. X,Y shift and X Y reversed buttons: These buttons allow you to move the image in the field of view (FOV) instead of having to physically move the camera.

If the camera has been mounted up side down or left to right you can correct this by reversing the camera axis image instead of re-mounting the camera.

12. Segment Screen: The camera image displayed is only half the actual size of the image. This is because the size of the image is greater than the window.

When in Segment screen mode you will see a segment of the full size image. This is either one of the four corners or the center.

13. Defaults button: Press this button with the shift key down to set all parameters to their default values.

14. Calibration: No longer required. As of last year, ultra low distortion lenses are being used that elliminate the need to calibrate the camers.

Ensure all settings are cleared by holding the ctrl key down and clicking the Enter button.

15. Scale: The system uses this value to calculate the distance the ball has travelled and - with the shutter speed - the ball speed.

The camera sees only pixels so a real distance-to-pixel scale factor must be used to calculate the real distance travelled.

16. Drivers: Trace angle Select this option so that when teeing off the launch angle is measured only from the trace and not from a pre-defined launch position.

The system then doesn't need to know the tee height.

Segment screen: The camera's resolution is double that of the camera view window.

If you want to see the image in full resolution then only a quarter segment of the image can be shown at a time. Top/Left, Botom/Left, Top/Right or Botton/right segments