Measurement probe systems for co-ordinate positioning apparatus

• US 20090070585A1
• Filed: 07/08/2008
• Published: 03/12/2009
• Est. Priority Date: 07/26/2007
• Status: Active Grant

• Current Assignee: Renishaw PLC
• Original Assignee: Renishaw PLC
• Inventors: Buckingham, Jamie, Hellier, Peter K., Styles, John, Prestidge, Tim, Fuge, Jonathan P.
• Granted Patent: US 8,464,054 B2
• Time in Patent Office: Days
• US Class Current: 713/168
• CPC Class Codes: G01B 21/047 Accessories, e.g. for positioning, for tool-setting, for measuring probes
• CPC Class Codes: G01B 2210/58 Wireless transmission of information between a sensor or probe and a control or evaluation unit
• CPC Class Codes: G01B 5/012 Contact-making feeler heads therefor
• CPC Class Codes: G06F 21/44 Program or device authentication
• CPC Class Codes: H04L 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• CPC Class Codes: H04L 9/3236 using cryptographic hash functions
• CPC Class Codes: H04L 9/3271 using challenge-response
• CPC Class Codes: H04W 12/069 using certificates or pre-shared keys
• CPC Class Codes: H04W 12/108 Source integrity

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.

Claims

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, wherein the measurement probe system comprises a data transfer portion for receiving data from and/or transmitting data to an associated unit, wherein the measurement probe system comprises 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 deflectable stylus and 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. An interface for a measurement probe system according to claim 1 in which the measurement probe of the measurement probe system comprises a data transfer portion, wherein the interface comprises a complimentary data transfer portion for receiving measurement data from the measurement probe and an output portion for outputting the measurement data, characterised in that the interface also comprises an authentication module for verifying the authenticity of the measurement probe.

16. A method of operating a measurement probe system comprising a measurement probe, the method comprising the steps of:

(i) using the measurement probe system to measure an object, and (ii) receiving data from and/or transferring data to an associated unit, characterised by the step (iii) of verifying the authenticity of the associated unit.

17. 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.

18. 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 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.

19. 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.

20. A measurement probe according to claim 19 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.

21. A measurement probe according to claim 19 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.