Calibration method of positioning of onboard device for acquisition and remote transmission of data relating to motion and driving parameters of vehicles and motorcycles

Abstract

A calibration method of the positioning of an onboard device of a vehicle with axes (x, y, z), wherein the device comprises at least one accelerometric sensor (S) which detects the accelerations to which the vehicle is subjected along axes (x', y', z') of the accelerometric sensor, angularly arranged with respect to the axes (x, y, z) of the vehicle with rotation angles ([alpha]x, [alpha]y, [alpha]z). The accelerometric sensor (S) acquires the acceleration values generated by the force of gravity G acting on the vehicle when the vehicle is stopped in a substantially horizontal position, and the accelerations generated by a plurality of events suffered by the vehicle, along the axes (x', y', z'). The travel direction of the vehicle is determined on the basis of a prevailing direction of theaccelerations generated by a plurality of events suffered by the vehicle. According to the method, a transformation matrix (R) is determined, which puts in relation the accelerations measured along the axes (x', y', z') with corresponding accelerations along the axes (x, y, z), wherein a first rotation angle ([alpha]x) and a second rotation angle ([alpha]y) are derived on the basis of acceleration values of the force of gravity detected along the axes (x', y, z') when the vehicle is stopped, and a third rotation angle ([alpha]z) is derived on the basis of the determined travel direction of the vehicle.

Description

technical field [0001] The invention relates to the technical field of on-board equipment for detecting data related to the movement and driving parameters of traffic vehicles. In particular, the invention relates to a calibration method for positioning an on-board device according to the preamble of claim 1 . Background technique [0002] Calibration methods are known, wherein during the initial installation steps of an on-board device for acquiring and remotely transmitting data related to the movement and driving parameters of the vehicle, an accelerometric sensor included in or connected to the on-board device must be based on a Or multiple predefined orientations (orientation and orientation) or are assembled depending on orientations meeting certain conditions. [0003] An accelerometric sensor is capable of measuring acceleration along multiple axes, by being three, and can be connected to the on-board device internally or by means of a wire or short-range wireless c...

AI Technical Summary

Problems solved by technology

[0012] The known methods described above understandably ensure the correct orientation of the z-axis, but not the correct determination of its direction, and in particular the correct orientation of the x- and y-axes

[0013] This limitation thus does not allow to determine with certainty whether the event measured along the x- or y-axis actually corresponds to sudden braking, to sudden acceleration, or to a sharp bend, and it does not allow proper reconstruction of accidents in which a vehicle has been involved Dynamics

[0014] In addition, the correctness of the installation is only entrusted to the aspect of the direction specified by the installer, so the installation is not very reliable, and long working hours of the installer are required

[0015] In addition, such a solution requires the accelerometer sensor to be external to the on-board equipment, which would be difficult to install in its entirety given this constraint

Between the on-board unit and the accelerometer sensor there is therefore a mandatory presence of wiring, since there are two hardware components (on-board unit and accelerometer) to be fixed, which increases the installation costs of the device

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