Sensor module comprising acceleration sensor and relative displacement sensor, damper and electronically controllable suspension system comprising the same, and method of controlling vehicle movement using the same

A damper comprising:

• a cylinder which is formed with a hollow portion therein;
• a piston rod which is inserted through an upper portion of the cylinder;
• a piston valve which is connected with an end of the piston rod so as to reciprocate in the cylinder, the piston valve including a fluid passing hole;
• a rod guide which air-tightly closes an upper end of the cylinder and has a though-hole in which the piston rod is inserted, wherein a groove pattern, in which a concave portion and a convex portion are formed alternately and which is formed in a direction substantially perpendicular to a movement direction of the piston rod, is formed on a portion of the piston rod;
• and
• a sensor module which is provided with an acceleration sensor for detecting an acceleration at least in a z-axial direction and a displacement sensor for detecting a displacement of the piston rod and which is coupled with the rod guide, the displacement sensor is having a non-contact type comprises,
• a magnet for generating magnetic field;
• a giant magneto resistance (GMR) sensor which is disposed between the magnet and the piston rod so as to detect a change of the magnetic field generated by the groove pattern when the piston rod is moved and thus to output an electric signal;
• and
• a signal processing part which processes an output signal from the GMR sensor and then outputs a square wave.

A method of controlling a vehicle movement of a vehicle using an electronically controllable suspension system having an acceleration sensor and a displacement sensor, comprising:

• a first step of measuring an acceleration data with the acceleration sensor and measuring a displacement data with the displacement sensor;
• a second step of obtaining a secondary acceleration data by differentiating the displacement data and obtaining a secondary displacement data by integrating the acceleration data;
• a third step of comparing the acceleration data with the secondary acceleration data and comparing the displacement data with the secondary displacement data to detect possible out of order of one of the acceleration sensor and the displacement sensor;
• a fourth step of analyzing the vehicle movement using a detected result of the acceleration sensor and the displacement sensor;
• and
• a fifth step of controlling the vehicle movement by feeding back an analyzed result and adjusting damping force of a damper.

A sensor module which is coupled to a damper so as to detect a relative displacement of a piston rod having a groove pattern and an acceleration of an object in which the damper is installed, comprising:

• a magnet for generating magnetic field;
• a giant magneto resistance (GMR) sensor which is disposed between the magnet and the piston rod so as to detect a change of magnetic field generated by the groove pattern when the piston rod is moved and thus to output an electric signal;
• a signal processing part which processes an output signal from the GMR sensor and then outputs a square wave;
• an acceleration sensor for detecting an acceleration at least in a z-axial direction;
• a housing in which the magnet, the GMR sensor, the signal processing part and the acceleration sensor are received;
• and
• a cable which is extended to an outside of the housing so as to transfer an output signal of the signal process part and the output signal of the acceleration sensor to a control module of a vehicle.