Inertial device with pedometer function and portable electric appliance incorporating said inertial device

• US 8,042,390 B2
• Filed: 01/30/2007
• Issued: 10/25/2011
• Est. Priority Date: 01/30/2006
• Status: Active Grant

• Current Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Inventors: Tronconi, Michele, Pasolini, Fabio
• Primary Examiner(s): Kwok; Helen C.
• Application Number:
  US11/669,096
• Publication Number:
  US 20070198187A1
• Time in Patent Office: 1,729 Days
• Field of Search: 734/93, 73489-492, 702/160, 702/176, 702/178, 702/141, 702150-154, 702/158
• US Class Current: 73/489
• CPC Class Codes: G01C 22/006 Pedometers
• CPC Class Codes: G01P 15/125 by capacitive pick-up

Abstract

An inertial device that is integratable in a portable electronic device includes: an inertial sensor for generating at least one raw acceleration signal in response to accelerations caused by movements of walking and running of a user of the pedometer; and a processing unit, associated to the inertial sensor for counting a number of steps of the user of the pedometer on the basis of the raw acceleration signal. The inertial sensor and the processing unit are both encapsulated within a single package for integrated circuits, which can be coupled to a circuit board of an electronic device and is provided with at least one connection terminal for making the number of steps available to the outside world.

Claims

1. An inertial device comprising:

an inertial sensor, configured to generate at least one raw acceleration signal in response to accelerations caused by movements of walking and running of a user of the inertial device; and

a processing unit, associated to said inertial sensor to count a number of steps of the user on the basis of said raw acceleration signal, said processing unit having;

a conversion chain configured to extract a usable acceleration signal from said raw acceleration signal; and

a detection circuit associated with said conversion chain configured to detect steps of the user on the basis of said usable acceleration signal and further configured to update said number of steps, said detection circuit having;

a counter register, configured to store said number of steps;

a first comparator, configured to compare said usable acceleration signal with a threshold value, the first comparator coupled to said counter register and configured to increment said number of steps in response to said usable acceleration signal exceeding said threshold value; and

a selective-enabling circuit, configured to enable incrementing said number of steps when said usable acceleration signal is lower than said threshold value and further configured to disable the incrementing said number of steps for a pre-determined time interval after said usable acceleration signal has exceeded said threshold value;

wherein said inertial sensor and said processing unit are both encapsulated within a single integrated circuit package, which can be coupled to a circuit board of an electronic appliance and including at least one connection terminal to make available said number of steps to the electronic appliance.

2. The inertial device according to claim 1, wherein said inertial sensor is a capacitive microelectromechanical sensor having first, second, and third detection axes that are mutually independent, the sensor configured to supply first, second, and third raw acceleration signals, respectively, in response to accelerations caused by movements of walking of the user, respectively, according to said first, second, and third detection axes.

3. The inertial device according to claim 2, wherein said conversion chain comprises a reading interface connectable to said inertial sensor configured to convert said first, second, and third raw acceleration signals cyclically in time-division, respectively, into a first, second, and third analog acceleration signals.

4. The inertial device according to claim 3, wherein said conversion chain comprises an analog-to-digital converter configured to convert said first, second, and third analog acceleration signals, respectively, into first, second, and third numeric acceleration signals.

5. The inertial device according to claim 4, wherein said conversion chain comprises a selection circuit, configured to receive said first, second, and third numeric acceleration signals and further configured to generate said usable acceleration signal based on d.c. components and a.c. components of said first, second, and third numeric acceleration signals.

6. The inertial device according to claim 5, wherein said usable acceleration signal corresponds substantially to the one a.c. component selected from among said first, second, and third numeric acceleration signals having the largest d.c. component in absolute value.

7. The inertial device according to claim 4, configured so as to make said first, second, and third numeric acceleration signals available to the circuit board.

8. The inertial device according to claim 1, wherein said time interval is programmable.

9. The inertial device according to claim 1, wherein said selective-enabling circuit comprises an enabling logic gate, having an output connected to said counter register, and a masking circuit configured to block said enabling logic gate for said time interval, in response to a switching of said output of said enabling logic gate.

10. The inertial device according to claim 1, wherein said detection circuit comprises a threshold-updating circuit configured to generate said threshold value on the basis of said usable acceleration signal.

11. The inertial device according to claim 10, wherein said threshold-updating circuit comprises an envelope detector configured to supply an envelope value of said usable acceleration signal, and a threshold-calculation stage coupled to said envelope detector and configured to generate said threshold value on the basis of said envelope value.

12. The inertial device according to claim 1, wherein said conversion chain and said detection circuit are made up of respective dedicated electronic circuits.

13. A portable electronic appliance, comprising:

an inertial device that includes;

an inertial sensor structured to generate at least one raw acceleration signal in response to accelerations caused by movements of walking and running of a user of the inertial device; and

a processing unit, associated to said inertial sensor, structured to count a number of steps of the user on the basis of said raw acceleration signal, said processing unit having;

a conversion circuit structured to extract a usable acceleration signal from said raw acceleration signal; and

a detection circuit structured to detect the steps of the user based on said usable acceleration signal and update said number of steps, said detection circuit having;

a counter register structured to store said number of steps;

a first comparator structured to compare said usable acceleration signal with a threshold value, the first comparator coupled to said counter register and structured to increment said number of steps in response to said usable acceleration signal exceeding said threshold value; and

a selective-enabling circuit structured to enable incrementing said number of steps when said usable acceleration signal is lower than said threshold value and further structured to disable the incrementing said number of steps for a pre-determined time interval after said usable acceleration signal has exceeded said threshold value;

wherein said inertial sensor and said processing unit are both encapsulated within a single package for integrated circuits, which can be coupled to a circuit board of an electronic appliance, the single package including at least one connection terminal for making available said number of steps to the electronic appliance.

14. The electronic appliance according to claim 13, comprising a control unit separate from said processing unit of said inertial device and coupled to said inertial device through said connection terminal, the control unit structured to receive said number of steps.

15. The electronic appliance according to claim 13, comprising a further inertial sensor, separate from said inertial sensor of said inertial device.

16. A portable electronic appliance, comprising:

a control unit structured to control operations of the appliance; and

an inertial device coupled to the control unit, the inertial device encapsulated in an integrated circuit package, and the inertial device structured to output a number of steps of a user of the appliance, the inertial device including;

an inertial sensor structured to generate an acceleration signal in response to accelerations caused by movements of the user; and

a processing unit coupled to the inertial sensor and structured to count the number of steps of the user based on the acceleration signal, said processing unit having

a counter register structured to store the number of steps;

a first comparator structured to compare the acceleration signal with a threshold value, the first comparator coupled to the counter register and structured to increment the number of steps in response to the acceleration signal exceeding the threshold value; and

a selective-enabling circuit structured to enable incrementing the number of steps when the acceleration signal is lower than the threshold value and further structured to disable the incrementing the number of steps for a pre-determined time interval after the acceleration signal has exceeded the threshold value.

17. The electronic appliance according to claim 16, further comprising a second inertial sensor, separate from the inertial sensor of the inertial device.

18. The electronic appliance according to claim 16, wherein the inertial sensor and the processing unit are integrated together on a semiconductor chip.