Where we are at
The REMOT project team was born to bring together the skills of individual members to realize a device able to provide movement operators with accurate data and true to reality. After a careful analysis of the technology used so far in the field and an accurate evaluation of the
methods of integration between IMU and GNSS that are currently commonly chosen for the study of human movement outdoors, we have worked to :
– Identify the technical characteristics necessary for it to be possible to have a great
accuracy not only to determine a position and its variations in terms of speed acceleration and therefore also of realized force and produced power, but because it is possible to determine the exact position of several points (segments that correspond to limbs, joints) of the same unit, which, if it moves as a whole, is because its segments move, then being able to obtain the information of movement of the segments of the “Human Point/Body” (so angular variations of joints, segmental accelerations, stride length, stride amplitude step frequency, speed, distance traveled, average and intermediate accelerations, average power);
-Identify the integration and communication issues between GNSS indicating the general position of the body in motion and the IMUs along the body, so that the inter-and intra-suite calibration provides real and reliable data for the decision-making process of the operators.
The structure of the device 1.0
The REMOT prototype represents a system consisting of two IMUs (Inertial Measurement Units) plus GNSS (Global Navigation Satellite System) all three integrated into the same unit to determine with the highest possible accuracy.
– position of the moving body unit
– position of joints upstream and downstream of motor muscles,
– step dynamics (amplitude, length, frequency, and their variations over time),
– three-dimensional movements of upstream and downstream joints of motor muscles,
– accelerations and hence magnitudes derived from the dimensions of the measured movements.
Tests
The tests now have the fundamental objective of testing the device during the step to determine the accuracy of calibration between the IMUs integrated. To make the resulting data are useful, we have identified positions for calibration :
-subject standing with the devices worn on the back, left foot, right foot, stop 1 ‘for calibration between devices
-subject in mid-stance position on the left foot, stop 1′ for the calibration between devices
-subject in mid-stance position on the right foot, stop 1′ for calibration between devices
-walk for 5′ on an athletic track
-walk for 10′ on an athletic track
-30′ walk on the athletics track
-60′ walk on the athletics track
-comparison with a manual test of mechanical cadence performed with the Incalza technique.
Why mid-stance as a calibration moment? Because during the dynamics of the stride at that
moment the acceleration approaches 0, becoming a reference for data analysis in identifying when a step ends before the stride ends before the next action begins.
Why track testing? For the exact distance of the track (400m) and because the manual mechanical cadence
is calculated precisely on the track and this makes the two approaches compare in the results.
How is the mechanical cadence manually calculated (Incalza method)? I time the subject along with the two straight stretches of the track, each 100m, and during this timing, I measure the time needed for the subject to perform 10 steps with the same foot which is 20 steps in total which give me the T20, from that :
-1200/T20 = ppm (steps per minute)
-(Speed in Km/h * 1000)/(ppm*60) = L (m) of the step
The ReMot project team can’t wait to show you all the details this new phase of ReMot in Lyon at the Isokinetic Conference.