Background

The key to the force plate system is the measurement of the movement of the center of gravity (COG) in the golf swing along with video recording of golfer’s full swing. Research
has shown that there are good COG patterns and bad COG patterns. By learning to identify the good from the bad, an instructor can help a student learn the golf swing in a more effective and efficient manner. Other systems out there in the market are either just COG measurement system or just video only system. Force plate combines both data and video capturing in a synchronized way, it detects and gives  notification when weight center is within certain zones or when certain body part in video is within certain predefined regions.

Specifications

Hardware

The following components were incorporated into the system design:

  • An aluminum plate or glasstop plate with 4-8 load cells
  • Force plate USB DAQ from HYTEK Automation, Inc.
  • Logitech USB webcam or DV camcorder
  • 12V power supply
Software

The force plate system works with commercial cameras such as USB webcam or DV camcorder. Below highlights some of software features that are implemented in Force plate system.

Data and Video Synchronization

Capturing

Measure force plate’s load cells’ data for every video frame that passing by and record data and video files in a synchronized way.

Playback

This system is able to step through each video frame and read out the saved matching load cells’ force data. This makes the synchronized playback an easy task.

Thumbnail Creating

This force plate system is able to get each video frames’s image data and create a thumbnail’s view of image sequences.

Video Object Detecting

This force plate system is able to pre-learn a body object’s color spectrum, this will be used later to track body object. It is able to pre-define some regions and zone in square shape. If the tracked object is falling within these zones, system will beep or make a pre-recorded sound. The object tracking parameters and warning sound files are configurable and saved in setup file.

Multiple Camera Capturing and Video Blending

It is very useful to utilizing multiple cameras to capture different angle of body movement during the full swing. The video blending functions allow capturing and playback of multiple video streams at the same time. The location of each video stream and transparency are adjustable. This makes video side by side compare or video overlay streams an easy task.

Force Data Capturing And Analyzing

By using force plate USB DAQ from HYTEK Automation, Inc., load cells’ data are measured. Center of gravity (COG) is calculated and displayed in real time in a “yellow snake” shape in graph. The percentage of forward, backward, left and right forces are also calculated and displayed in numbers and bar graph.

Summary

This force plate system makes golfer’s life easier to understand the weight transfer in data and video form. The same system can also be used for baseball training or physical therapy.