Method for correcting a trajectory in a personal movement assistance device equipped with sensors

A method for correcting a movement trajectory in a movement assistance device for at least one person, the movement assistance device being driven by at least one motor, and directed by a steering control module, according to a first rotational speed, and a first translational speed, which are determined according to one or more directives received by means of an input interface, the speed values constituting the coordinates of a command point in a movement coordinate system, the movement assistance device being equipped with at least one sensor device, and a control unit, the sensor device being configured such that it performs a measurement in a defined direction relative to the movement axis of the movement assistance device, the method comprising the steps of measuring a distance between the at least one sensor or a predetermined point of the movement assistance device and an obstacle present in the direction, and the method further includes the steps of:

• separating, in particular according to the distance measured, the coordinate system, representing pairs of the values of translational speeds and rotational speeds into half-planes, using at least one separating straight line, one of the half-planes of the coordinate system corresponding to a permissible travel space, the other of the two half-planes corresponding to a travel exclusion zone of the movement assistance device,
• determining a second rotational speed and a second translational speed by projecting the command point into the permissible space,
• controlling the one or more motors and the steering control module, respectively as a function of the second translational speed, and the second rotational speed previously determined,
• the at least one separating straight line being defined by the equation:
• Jvν+Jωω≤λ(s−s*)
• wherein:
• ν is an instantaneous translational speed of the device,
• ω is an instantaneous rotational speed of the device,
• λ is a constant,
• s is the distance measured, and
• s* is a minimum distance measured to the obstacle, and
• Jv and Jω are scalar components respectively derived from the speeds cv and cω of the corresponding sensor in the coordinate system.