ULTRA-LIGHT AND ULTRA-ACCURATE PORTABLE COORDINATE MEASUREMENT MACHINE

1 . A portable coordinate measurement machine (CMM) comprising:

a manually-positionable articulated arm having first and second ends, the articulated arm including a plurality of arm segments and a plurality of rotary joints, the first end including a connector configured to connect to a measurement probe and the second end including a base;

wherein at least one of the rotary joints from the plurality of rotary joints includes:

first and second bearings;

a shaft that engages an inner diameter of the first bearing and an inner diameter of the second bearing, the shaft configured to rotate about an axis of rotation of the first bearing and the second bearing;

a housing having at least one port that engages at least one of an outer diameter of the first bearing and an outer diameter of the second bearing; and

at least one transducer configured to output an angle signal corresponding to an angle of rotation of the shaft relative to the housing about the axis of rotation, and

an electrical circuit including a serial communication circuit configured without a dedicated capture wire or a dedicated trigger wire to receive the angle signal and other signals from other transducers in the CMM.

2 . The CMM of claim 1 , wherein the electrical circuit is configured to output an agglomeration of the angle signal and the other signals to provide information corresponding to a position of the measurement probe relative to the base.

3 . The CMM of claim 1 , wherein the serial communication circuit includes a pair of bidirectional wires.

4 . The CMM of claim 1 , wherein the serial communication circuit includes two pairs of unidirectional wires.

5 . The CMM of claim 1 , wherein the serial communication circuit transmits capture commands at predetermined intervals to respective processors of the rotary joints.

6 . The CMM of claim 1 , wherein the serial communication circuit transmits capture commands at predetermined intervals to respective processors of the rotary joints and, in response, the processors each generates an internal capture with a fixed calibrated latency among the processors.

7 . The CMM of claim 1 , further comprising:

a first processor associated with a first joint from the plurality of rotary joints and a second processor associated with a second joint from the plurality of rotary joints, wherein each of the first processor and the second processor receives a capture command via the serial communication circuit even though the serial communication circuit is configured without a dedicated capture wire.

8 . The CMM of claim 1 , further comprising:

a first processor associated with a first joint from the plurality of rotary joints and a second processor associated with a second joint from the plurality of rotary joints,

wherein the first processor receives a first capture command via the serial communication circuit even though the serial communication circuit is configured without a dedicated capture wire and, thereafter, the second processor receives a second capture command via the serial communication circuit even though the serial communication circuit is configured without a dedicated capture wire, and

in response to receiving the first capture command, the first processor generates an internal capture with a latency and, in response to receiving the second capture command, the second processor generates an internal capture with the same latency.

9 . The CMM of claim 1 , wherein the serial communication circuit transmits a common capture command to respective processors of the rotary joints.

10 . The CMM of claim 1 , further comprising:

a first processor associated with a first joint from the plurality of rotary joints and a second processor associated with a second joint from the plurality of rotary joints,

wherein the first processor receives a capture command via the serial communication circuit even though the serial communication circuit is configured without a dedicated capture wire and, thereafter, the second processor receives the capture command via the serial communication circuit even though the serial communication circuit is configured without a dedicated capture wire, and

in response to receiving the capture command, the first processor generates an internal capture with a first latency and the second processor generates an internal capture with a second latency different from the first latency.

11 . A portable coordinate measurement machine (CMM) comprising:

a manually-positionable articulated arm having first and second ends, the articulated arm including a plurality of arm segments and a plurality of rotary joints, wherein at least one of the rotary joints from the plurality of rotary joints includes:

first and second bearings;

a shaft configured to rotate about an axis of rotation of the first bearing and the second bearing; and

at least one transducer configured to output an angle signal corresponding to an angle of rotation of the shaft about the axis of rotation, and

a serial communication circuit configured to communicate the angle signal, the serial communication circuit configured without at least one of a dedicated capture wire and a dedicated trigger wire.

12 . The CMM of claim 11 , comprising a transducer configured to output an agglomeration of the angle signal and other signals generated by the CMM to provide coordinate measurement information.

13 . The CMM of claim 11 , wherein the serial communication circuit includes a pair of bidirectional wires in a half-duplex configuration.

14 . The CMM of claim 11 , wherein the serial communication circuit includes two pairs of unidirectional wires in a full-duplex configuration.

15 . The CMM of claim 11 , wherein the serial communication circuit transmits a first capture command directed to a first processor of a first joint of the plurality of rotary joints and, after a predetermined time interval, transmits a second capture command, different from the first capture command, directed to a second processor of a second joint of the plurality of rotary joints.

16 . The CMM of claim 11 , wherein the serial communication circuit transmits a first capture command directed to a first processor of a first joint of the plurality of rotary joints and, after a predetermined time interval, transmits a second capture command, different from the first capture command, directed to a second processor of a second joint of the plurality of rotary joints, and

in response to the first capture command, the first processor generates an internal capture with a latency L from the time of receiving the first capture command, and

in response to the second capture command, the second processor generates an internal capture with the latency L but from the time of receiving the second capture command.

17 . The CMM of claim 11 , further comprising:

a first processor associated with a first joint from the plurality of rotary joints and a second processor associated with a second joint from the plurality of rotary joints, wherein each of the first processor and the second processor receives a capture command via the serial communication circuit even though the serial communication circuit is configured without a dedicated capture wire.

18 . The CMM of claim 11 , further comprising:

a first processor associated with a first joint from the plurality of rotary joints and a second processor associated with a second joint from the plurality of rotary joints,

wherein the first processor receives a first capture command via the serial communication circuit even though the serial communication circuit is configured without a dedicated capture wire and, thereafter, the second processor receives a second capture command via the serial communication circuit even though the serial communication circuit is configured without a dedicated capture wire, and

in response to receiving the first capture command, the first processor generates an internal capture with a latency and, in response to receiving the second capture command, the second processor generates an internal capture with the same latency.

19 . The CMM of claim 11 , wherein the serial communication circuit transmits a common capture command to respective processors of the rotary joints.

20 . The CMM of claim 11 , further comprising:

a first processor associated with a first joint from the plurality of rotary joints and a second processor associated with a second joint from the plurality of rotary joints,

wherein the first processor receives a capture command via the serial communication circuit even though the serial communication circuit is configured without a dedicated capture wire and, thereafter, the second processor receives the capture command via the serial communication circuit even though the serial communication circuit is configured without a dedicated capture wire, and

in response to receiving the capture command, the first processor generates an internal capture with a first latency and the second processor generates an internal capture with a second latency different from the first latency.