Abstract: The invention relates to a system for assisted ascent or descent, comprising: —a staircase comprising at least one instrumented mobile step, equipped with at least one sensor for measuring the centre of pressure of a user and at least one lifting actuator designed to raise or lower the step according to a degree of vertical freedom; —a calculation unit connected to the sensor for measuring the centre of pressure and to the lifting actuator, the calculation unit being configured to calculate at least the position, the speed of movement and the acceleration of the user from the centre of pressure measured by the sensor and, depending on the values calculated, control the lifting actuator.