Measurement probe systems for co-ordinate positioning apparatus

Abstract

A measurement probe, such as a touch trigger measurement probe, is described that comprises a measurement portion for measuring an object and a data transfer portion for receiving data from and/or transmitting data to an associated unit. The measurement device also comprises an authentication module for verifying the authenticity of the associated unit. The authentication module may include a processor for running a one-way hash algorithm. Authenticity may be established using a challenge and response authentication process.

What is claimed is: 
     
         1 . A measurement probe system comprising a measurement probe mountable to co-ordinate positioning apparatus,
 the measurement probe having a measurement portion for measuring an object, comprising a deflectable stylus,   wherein the measurement probe system comprises;
 a data transfer portion for receiving data from and/or transmitting data to an associated unit, and 
 an authentication module for verifying the authenticity of the associated unit. 
   
     
     
         2 . A measurement probe system according to  claim 1 , wherein the authentication module comprises a processor that, in use, runs an encryption algorithm. 
     
     
         3 . A measurement probe system according to  claim 2 , wherein the encryption algorithm is a one-way hash algorithm. 
     
     
         4 . A measurement probe system according to  claim 1 , wherein the authentication module comprises a random data string generator. 
     
     
         5 . A measurement probe system according to  claim 1 , wherein the authentication module comprises a secure memory for storing a secret key. 
     
     
         6 . A measurement probe system according to  claim 5 , wherein the authentication module verifies the authenticity of the associated unit using a challenge and response process, wherein the challenge and response process confirms that the associated unit holds the same secret key as the secure memory of the authentication module without disclosing the secret key. 
     
     
         7 . A measurement probe system according to  claim 1 , wherein the data transfer portion comprises a transmitter and/or a receiver for providing a wireless communications link with an associated unit. 
     
     
         8 . A measurement probe system according to  claim 1 , wherein the data transfer portion comprises at least one electrical contact for providing a conductive electrical connection to an associated unit. 
     
     
         9 . A measurement probe system according to  claim 1  in which the measurement portion generates measurement data for transmission to an associated unit by the data transfer portion, wherein the data transfer portion only transmits the measurement data if the authentication module has verified the presence of an authentic associated unit. 
     
     
         10 . A measurement probe system according to  claim 1 , wherein an associated unit is arranged to transmit information relating to measurement probe system operation, wherein said information is only acted upon by the measurement probe system if the authentication module has verified that the associated unit is authentic. 
     
     
         11 . A measurement probe system according to  claim 1 , wherein the measurement portion of the measurement probe comprises a deflection measurement mechanism for measuring deflection of the deflectable stylus. 
     
     
         12 . A measurement probe system according to  claim 1 , further comprising at least one of a probe interface, a numeric controller and a computer. 
     
     
         13 . A measurement kit comprising a measurement probe system according to  claim 1  and an associated unit, wherein the associated unit stores information to be transmitted to the measurement probe system. 
     
     
         14 . A measurement kit comprising a measurement probe system according to  claim 1  and an associated unit, wherein the associated unit comprises an interface for receiving measurement data from the measurement probe system. 
     
     
         15 . A measurement probe for co-ordinate positioning apparatus, the measurement probe comprising;
 a measurement device for generating measurement data indicative of the position of at least one point on the surface of an object;   a communications device for communicating with a remote probe interface; and   an authentication device for determining if the remote probe interface is an authentic remote probe interface,   wherein the communications device passes the measurement data to the remote probe interface only when the authentication device has determined that the remote probe interface is an authentic remote probe interface.   
     
     
         16 . A measurement probe according to  claim 15  wherein the authentication device comprises a secure memory for storing a secret key, wherein the authentication device determines the authenticity of a remote probe interface using a challenge and response authentication process, the challenge and response authentication process confirming that a remote probe interface holds the same secret key as is held in the secure memory of the authentication module, wherein the challenge and response authentication process does not disclose the secret key. 
     
     
         17 . A measurement probe for co-ordinate positioning apparatus, the measurement probe comprising;
 a measurement device for measuring an object;   an interface for providing a data connection with an associated data storage unit,   a communications device for receiving data from an associated data storage unit connected to the interface,   an authentication device for determining if a data storage unit connected to the interface is an authentic data storage unit;   wherein data stored on a data storage unit connected to the interface is used by the measurement probe only when the authentication device has determined that the data storage unit connected to the interface is an authentic data storage unit.   
     
     
         18 . A measurement probe according to  claim 17  wherein the communications device receives data from an associated data storage unit that comprises at least one of a trigger count value, a probe operation time value, a probe operating instruction and a firmware update. 
     
     
         19 . A measurement probe according to  claim 17  wherein the authentication device comprises a secure memory for storing a secret key, wherein the authentication device determines the authenticity of a data storage unit using a challenge and response authentication process, the challenge and response authentication process confirming that a data storage unit holds the same secret key as is held in the secure memory of the authentication module, wherein the challenge and response authentication process does not disclose the secret key.