In search of the elusive perfect golf swing.
Even the top, professional golfers find it virtually
impossible to find and keep the perfect swing, so
what chance the beginner and club player?
Both could soon benefit from a device currently being developed
by Project Electronics for one of its clients. Called G-Force, the
new device will clip onto the golf club near the head and an LCD
readout will indicate to how close the swing was to perfection.
Sounds simple but developing the algorithm to convert a golf
swing into a single number has proved to be far from easy.
Project Electronics needed to measure the acceleration
throughout the stroke and use this to locate the centre of rotation
of the golfer's body. This involved fixing accelerometers near
the head of the club and on the golfer's wrist to produce an
acceleration curve that would indicate the "quality" of the swing.
As even novice golfers are sensitive to the weight and balance
of the club, it was essential that the accelerometers were not so
large and heavy as to influence the swing of the club. At only
5.74 mm in diameter, 4.3 mm long and weighing 0.4 grams, the
Kistler 8778A500, one of the smallest and lightest accelerometers
commercially available, was ideal for the job.
Housed in a small plastic holder, the accelerometer could be
quickly attached to the club without tools and, more importantly,
without damaging the shaft.
To gather the required data, golfers at a local driving range were
asked to cooperate. A representative sample of novice and
expert, male and female golfers of different sizes were asked
to complete a brief questionnaire before being fitted with the two
accelerometers. The cable from the accelerometer on the club
was taped to the shaft and run up the arm of the subject along
with the cable from the wrist accelerometer, over the shoulder
and to a data logger. The subject was then asked to drive
several times using their normal swing, the whole process
taking only 20 minutes.
From the mass of data collected over a whole day, Project
Electronics is developing the algorithm to convert the acceleration
experienced by the club head into a number indicating the
quality of the swing. When the design is finalised, the G-Force
device will be totally self-contained with an accelerometer chip,
processing circuits and readout mounted on a small printed
circuit board in a plastic moulding that clips onto the club shaft.
Immediately after each stroke, on the course or the driving range,
the golfer will be able to see just how good his or her swing really
Project Electronics' Technical Director, Meryck Willeard, says,
"What initially seemed to be a relatively straightforward consultancy
project soon developed onto a complex investigation. It took the
combined resources of both Kistler Instruments and Project
Electronics to solve the problem of measuring acceleration at
club head and golfer's wrist without the measuring instruments
Kistler Instruments is one of the worlds leading manufacturers
of piezoelectric and piezoresistive precision sensors covering
acceleration, force, pressure and torque. Established in
Wintherthur (Switzerland) in 1957, Kistler is represented in over
50 countries and has subsidiaries in Germany, France, Italy, UK,
Japan, USA, China, Korea and Singapore.
Heavy investment in research and development, 15% of staff
worldwide are engaged in research and development, has
generated a number of innovations using piezoelectric,
piezoresistive and capacitive techniques to provide solutions
to numerous force, pressure and acceleration measuring problems.
These innovations include the world's first commercial quartz sensor,
two-wire constant current technology to integrate sensors with
microelectronic circuitry, high-temperature pressure sensors for
use up to 400 deg C and three-component force measuring sensors.
For more information, please contact :-
Kistler Instruments Ltd.
13 Murrell Green Business Park, London Road, Hook RG27 9GR
Tel: +44 (0)1256 741550
Fax: +44 (0)1256 741551