| 摘要 |
This apparatus measures the XYZ coordinates of a point on a part to determine its position in space. The apparatus comprises a movable measuring assembly and a remote processing station. The assembly includes serially arranged rigid arm members pivoted by rotary joints to a wheeled base and to a probe for engaging the part. A rotary encoder is mounted at each joint for measuring the rotation angle of one arm member relative to the other; each encoder sends an analog sinusoidal signal to an associated micro-controller which comprises an analogic to digital converter and a processing unit to generate a digital signal indicative of an instantaneous rotation angle. All the controllers are connected in a network and the resultant of the simultaneous readings of all of the encoders is sent by a radio frequency transmitter mounted on the base to the remove processing station equipped with a radio receiver and a computer which processes the transmitted data into measurement coordinates. To increase the measuring precision, each micro-controlller is capable of taking several instantaneous readings of the sinusoidal pulse emitted by the encoder and to calculate an average of said readings. The base has an automatic levelling device; each arm has a temperature sensor for effecting temperature compensation. Data recording is automatically stopped if the machine is subjected to excessive vibration or shocks. |
