WhirlTrak

Helitune’s focus on engineering support services includes adaptation of Tracking Systems for Rotor Towers to individual customer specifications, to help OEMs and operators make their Rotor Tower measurements more sophisticated and reliable. Helitune has recently been working with various OEMs to engineer and deliver installation of a bespoke Rotor Tower Blade Tracking System.

Background

During production, qualification,
maintenance or repair of main rotor blades,
Rotor Test Stands are regularly utilised
within a static rotorhead environment in
order to simulate the forces to which
these blades will be subjected, before
installing onto a helicopter. Different
measurements provide information on the
status of the blades in terms of their
interaction, e.g. thrust, drag (lead/lag),
tip tracking, vibration characteristics, etc.

The WhirlTrak system comprises a
permanently-installed tracking camera
(Helitune’s own proven RT-TipTrak design),
along with an associated track
measurement system, supported by a wind
measurement system and (optional) CCTV
camera.

Helitune Engineers were able to integrate
the system with the tower control system,
in accordance with the OEM’s specific
requirements, so that it benefits from
computerised test reports to replace the
previous paper-based reporting system,
making analysis of the results much easier
and more efficient.
 
 
Operation

A whiteboard ‘target’ is provided to ensure
effective operation across a wide range of
light conditions.

Additional flood light can be provided for
operation during darkness, allowing
continuous 24-hour tracking operation.
 
 
Analysis of Results and User Interface
Details

The user interface is programmed so that
no other software is required for rotor
track data acquisition, providing a fully
integrated solution for the configuration
of the RT-TipTrak tracking camera, display
of real-time results, display of flat track
and collective track plots, calculation of
blade adjustments, storage of track result
data and generation of the output data
report. All track measurement results are
stored onto an MS SQL database for data
archiving and subsequent retrieval.

The user interface allows for the review of
previous rotor tower track results. Data
collection activities are organised into
sequences of ‘Tests’ and ‘Runs’. This
allows multiple measurement runs to be
completed on a blade set as part of the
same test, facilitating simple retrieval and
review of all measured data from a specific
blade set. Tracking runs are
pre-configured according to the required
blade measurement procedure – multiple
blade measurement procedures can be
configured for each blade. System
operators are able to easily select the
required blade measurement procedure at
the beginning of a test, allowing the
system to automatically pre-configure
itself into the required operating state.

Data reports are generated automatically
and all data can be exported into an MS
Excel compatible storage format – allowing
complete flexibility in formatting and
presentation of output results, certificates
and reports.

The Rotor Tower Controller software
automatically configures the blade tracker
hardware according to the pre-selected
blade type. Live track results are displayed
using both real-time current and averaged
markers. Stored results for each data
measurement point are plotted to the
historic display graph in the centre of the
live track display.

Historic results can be viewed using the
Rotor Tower Software or exported
automatically to MS Excel for report
template generation.

                     Hardware
 

               WhiteBoard Target
 

                    RT-TipTrak
               and Video Camera
 
 
Outline Specification:

  • Provision of continuous real-time track
    measurement display
  • Measured rotor track accuracy of better
    than ±1.27mm (±0.050 inch)*
  • Measured rotor track resolution of better
    than ±1.27mm (±0.050 inch)*
  • Averaged rotor track resolution of better
    than ±0.254mm (±0.010 inch)*
  • Rotor RPM measurement range of
    60RPM to 1200RPM
  • Optional digital I/O interface to Rotor
    Tower Control System for tower state
    recognition (collective pitch interface)
  • Digital serial O/P broadcast interface for
    transmission of track results to third
    party systems
  • Automatic configuration of RT-TipTrak
    tracking device based upon blade type
    to be tested
  • Track results storage based upon user
    track condition selection
  • Blade adjustment calculation based
    upon measured track results
  • Track data archiving and results report
    generation
  • Operating temperature range of -20°C to
    +60°C for all Rotor Tower mounted
    hardware
  • Solid state solution with no moving parts
  • Wide field of view measurement tracker,
    allowing a fixed installation to track
    multiple blade types
  • The tracking camera is a variant of the
    existing Helitune RT-TipTrak product,
    which has proven performance in a
    permanently installed DO-160E aircraft
    environment

* Note: Stated accuracy achievable
depends upon physical installation
characteristics of the individual
rotor tower.