Higher Speed, Smoother Motion.
Date: 25 February 2008

Anthony Best Dynamics turned to leading independent precision motion specialists Heason Technology for rotary actuators as its customer base sought greater speed and smoother motion.
Anthony Best Dynamics supplies advanced
testing systems to the global motor industry for research and
development and for production quality control. They design and
manufacture specialised systems for kinematics and compliance
testing, vehicle dynamics testing on the track and steering system
testing.
The moving body Suspension Parameter Measurement Machine (SPMM) is
a proven machine for use in Kinematics and Compliance
testing.
ABD's kinematics and compliance measurement machines measure the
quasi-static suspension characteristics that are important to ride
and handling. The machines measure the kinematic characteristics
due to suspension and steering system geometries, and compliances
due to suspension springs, anti-roll bars, elastomeric bushes and
component deformations.
The SPMM uses precision electric actuators that avoid all the
problems traditionally associated with hydraulic test
equipment.
The first SPMM manufactured by AB Dynamics was installed in 1997
and is still testing vehicles on a daily basis without requiring
any major maintenance.
A large number of parameters may be evaluated, the principal ones
being suspension rates and hysteresis, bump-steer, roll-steer, roll
stiffness distribution, longitudinal and lateral compliance steer,
and steering system characteristics. Knowledge of these parameter
values and characteristics is an essential aid to the thorough
understanding of a vehicles performance in terms of ride, steering
and handling. It comprises a rigid centre table upon which the
vehicle is mounted.
The centre table can be moved with six degrees of freedom for
kinematics measurements. Individual wheel stations have three
degrees of freedom (X, Y, and Delta) and integral six axis load
platform.
Wheel positions are measured using an accurate and easy to use
optical encoder system. The optional MIMS (Moment of Inertia
Measurement System) enables the SPMM to quickly measure vehicle
centre of gravity, and inertias.
The challenge put forward to Heason's design team was to develop a
compact, zero backlash, precision gear actuator which would allow
ABD to offer higher rotation speeds whilst providing exceptionally
smooth motion. Coupled with this, Heason's design brief was to
package the new actuator to fit within an existing casting of the
machine.
Working closely with engineering expertise from Spinea SA (who
Heason exclusively represent in the UK), Heason's mechanical design
team developed a compact, zero backlash gear actuator based around
a custom Spinea TwinSpin bearing reducer with an Emoteq integrated
frameless, brushless servo motor and high resolution feedback
device.
The new package did not only achieve the higher rotation speed,
but also surpassed the previous 'zero backlash' gear system in
terms of smoothness, all in a more compact package.
Actuator performance - 495Nm Continuous Torque, 1237Nm Repeatable
Torque, 1,000 Nm/Arcmin Tilting Stiffness, 110 Nm/Arcmin Torsional
Stiffness, < 1.0 Arcmin Maximum Lost Motion, 19,200 N Rated
Radial Force, 27,900 N Maximum Axial Force. Encoder Resolution
1,250,000 Counts/Rev. Actuator size - Maximum Diameter 190mm by
Maximum Length 164mm.
Heason Technology is a leading independent supplier of Precision
Motion Control Equipment specialising in 'Motion System
Integration' and is a major player in many diverse
markets. Heason has considerable experience in precision
motion control.
Not only does Heason sell some of the leading global brands of
precision motion control components, but using these products and
components and its considerable expertise, Heason engineer custom
and bespoke solutions for individual customer requirements, such as
Anthony Best Dynamics.





