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Publication Date: 2016-Jan-12
Document File: 4 page(s) / 2M

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The Prior Art Database

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 52% of the total text.

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System for feedback mechanism for motorized rotation using Displacement sensors

    The invention describes an approach to measure small displacement of a rotating handle on the application of external force on it. This displacement measurement is further given to the motor as a feedback to control motion. The Linear Incremental Magnetic Position Sensor can measure positive or negative displacement. This comprises of single-chip ICs with integrated Hall elements mounted on front plate for measuring linear displacement using multipolar magnetic strip mounted on back plate.

    Keywords related to the invention: Displacement measurement, Multipole sensor, Magnetic Strip, Hall element, Motion Control, Tube rotation, Diagnostic Radiography, Power steering.

    Typically in an x-ray system there are manual or motorized motions. In this system the manual rotation of the system is assisted by motor. The ceiling suspension alpha drive rotation is one of the important movements needed by the operator in diagnostic X-ray radiography systems. However, as per the functional requirements, this rotational motion about the alpha axis needs to be manually controlled by the operator with external motor assisting the movement. So, there is a need to sense the externally applied manual force in order to send this sensation as a feedback to the motor for automatically controlling its motion.

    In the existing the Drive system of Ceiling Suspension The servo loop is not very sensitive to the torque the user applies to the handle due to the gear reduction.

Present Solution

    Existing option is the use of S-beam load cell sensor. The principle of operation of the Strain Gauge load cell is based on the fact that the resistance of the electrical conductor changes when its length changes due to stress. Cu Ni alloy is commonly used in strain gauge construction as the resistance change of the foil is virtually proportional to the applied strain. The change in resistance of the strain gauge can be utilized to measure strain accurately when

    The major problem with using such a sensor is that its calibration is difficult. Moreover, as the load cell is made of silicon and there are chances of increase in the

Alpha Axis

connected to an appropriate measuring circuit.

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temperature to be more than 50 degree, silicon might melt and the load cell may not work. Also, the load cell sensor is expensive.

Problems or disadvantages overcome by the invention

1. As the load cell is made of silicon and there are chances of increase in the temperature to be more than 50 degree, silicon might malfunction at such temperatures and the load cell may not work.

2. Output signal to be converted from Analogue to digital, there-by leading to loss of accuracy.

The main element(s) of the invention

1. The invention claims a mechanism for controlling the motion of a rotating / translating body by magnifying applied force.

2. The invention claims doing the above using Linear / Rotati...