PORTABLE DEVICE AND METHOD FOR MEASUREMENT AND CALCULATION OF DYNAMIC PARAMETERS OF PEDESTRIAN LOCOMOTION
First Claim
1. Method for the measurement and calculation of dynamical parameters of pedestrian locomotion comprising:
- filtering measurements of angular velocity of a single-axis gyroscope by means of a low-pass filter, in order to continuously determine the drift of this sensor;
integrating the difference, between the gyroscope signal and said drift, obtaining the angle, θ
, of orientation with respect to the horizontal and vertical axis, of the referential defined by the axes of at least two single-axis accelerometers, or analogously at least one double-axis accelerometer;
converting the accelerometers measurements to a new referential by a rotation, said rotation obtained from said angle, θ
, of orientation, where, in the new referential, one of the axis is horizontal and the other vertical;
integrating the accelerometer measurements over time to obtain the horizontal and vertical velocities;
integrating the measurements of horizontal and vertical velocities in order to obtain the horizontal and vertical components of position;
estimating the offset, Δ
θ
, of the angle θ
, and the vertical offset, Δ
A_v, of the vertical acceleration A_v, or the horizontal offset, Δ
A_h, of the horizontal acceleration A_h, and the errors, Δ
V_h and Δ
V_v, respectively, in horizontal and vertical velocities, V_h and V_v;
with said offsets and errors being used as state variables of an extended discrete Kalman filter;
updating the state of said Kalman filter every time two or more force sensors indicate the lower limb is in contact with the ground, exerting a pressure p above a threshold high enough to consider that said limb'"'"'s velocity is zero, in the form of state observation of null velocities V_h and V_v;
recording the series of activations of the force sensors to determine the locomotion cycles;
recording force sensor data and the instants when they occur within the locomotion cycle for the detection of eventual abnormalities.
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Accused Products
Abstract
The disclosed subject matter relates to a portable and autonomous device and corresponding method for the measurement, recording and calculation of dynamic parameters of the pedestrian locomotion of its bearer. The method hereby disclosed allows determining the distance effectively travelled, the velocity of displacement and the pressures exerted on the contact surface of the lower limb with the ground, during the pedestrian locomotion, according to its different phases. Through sensors strategically placed, accelerations, angular velocities and pressures are measured and recorded on the control unit. The device disclosed includes a processing unit that implements the method disclosed and a communication unit to transfer to an external unit the calculated parameters. The disclosed invention can be used in applications that involve monitoring parameters of the locomotion activity or daily ambulation of its bearer, in the areas of health and sports or in any physical and occupational activities.
18 Citations
16 Claims
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1. Method for the measurement and calculation of dynamical parameters of pedestrian locomotion comprising:
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filtering measurements of angular velocity of a single-axis gyroscope by means of a low-pass filter, in order to continuously determine the drift of this sensor; integrating the difference, between the gyroscope signal and said drift, obtaining the angle, θ
, of orientation with respect to the horizontal and vertical axis, of the referential defined by the axes of at least two single-axis accelerometers, or analogously at least one double-axis accelerometer;converting the accelerometers measurements to a new referential by a rotation, said rotation obtained from said angle, θ
, of orientation, where, in the new referential, one of the axis is horizontal and the other vertical;integrating the accelerometer measurements over time to obtain the horizontal and vertical velocities; integrating the measurements of horizontal and vertical velocities in order to obtain the horizontal and vertical components of position; estimating the offset, Δ
θ
, of the angle θ
, and the vertical offset, Δ
A_v, of the vertical acceleration A_v, or the horizontal offset, Δ
A_h, of the horizontal acceleration A_h, and the errors, Δ
V_h and Δ
V_v, respectively, in horizontal and vertical velocities, V_h and V_v;
with said offsets and errors being used as state variables of an extended discrete Kalman filter;updating the state of said Kalman filter every time two or more force sensors indicate the lower limb is in contact with the ground, exerting a pressure p above a threshold high enough to consider that said limb'"'"'s velocity is zero, in the form of state observation of null velocities V_h and V_v; recording the series of activations of the force sensors to determine the locomotion cycles; recording force sensor data and the instants when they occur within the locomotion cycle for the detection of eventual abnormalities. - View Dependent Claims (2, 3, 4, 5, 6)
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7. Device for the measurement and calculation of dynamical parameters of pedestrian locomotion, comprising the following elements:
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two single-axis accelerometers, or analogously one double-axis accelerometer; one single-axis gyroscope; at least two force sensors, suitable for determining when there is full contact of the lower limb with the ground one recursive self-calibrating estimator of corrections to the horizontal and vertical velocities of the device, said estimator being self-calibrating when there is full contact of the lower limb with the ground and when, therefore, velocities are null. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14, 15, 16)
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Specification