Patent Application
20110161015
1. Technical Field
The present disclosure relates to detection modules, and particularly, to a detection module employing force sensors.
2. Description of the Related Art
Center-of-gravity measurement and motion detection are widely used in automation production lines, video games, and virtual-reality technologies, among other applications. Typically, a detection module using a Wheatstone bridge is used to measure an unknown electrical resistance by balancing two legs of a bridge circuit, one of which includes an unknown component. Generally, the unknown electrical resistance is detected by a resistance strain gauge adhered to a load carrying member on which a force is applied. However, the Wheatstone bridge outputs analog signals which must be amplified via an amplifier circuit and converted to digital signals via an A/D conversion circuit, before transmission to a processing unit or an actuator. In addition, the center-of-gravity measurement or motion detection modules utilizing the resistive strain gauges suffer from relatively low precision and slow response.
Therefore, there is room for improvement within the art.
The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout several views.
The disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.
Referring to
In this embodiment, the detection module 200 is provided with four MEMS force sensors 21, each of which can be a piezoelectric sensor or a capacitance sensor. The four MEMS force sensors 21 are mounted on corresponding support members 11 which carry the weight of the measured object 10. The four MEMS force sensors 21 are arranged in a predetermined matrix, with distance between any two MEMS force sensors 21 predetermined. Each MEMS force sensor 21 is adapted to detect force applied on a corresponding measured point and output digital corresponding signals.
The processing unit 22 communicates with the MEMS force sensors 21 via data transmission channels and receives and processes the digital signals from the MEMS force sensors 21. When the measured object 10 is at rest, the sum of the force and moment applied thereon is equal to zero, the processing unit 22 calculates the center of gravity of the measured object 10 based upon the predetermined distance between any two of the four MEMS force sensors 21 and data values corresponding to the digital signals from the MEMS force sensors 21.
The wireless transmission unit 23 is electrically connected to the processing unit 22 and coupled to the control unit 25 via wireless communication interface. The control unit 25 includes a user interface 251 to show the data value for the force detected by the MEMS force sensors 21 on a screen, and/or generate instructions to the wireless transmission unit 23. In one embodiment, the wireless transmission unit 23 is a Bluetooth transmission unit. In other embodiments, the wireless transmission unit 23 can be omitted, and the control unit 25 directly coupled to the processing unit 22 to receive and process the signals from the processing unit 22.
The power supply unit 24 provides power to the processing unit 22 and wireless transmission unit 23. A DC-to-DC (direct current to direct current) conversion unit 26 connecting the power supply unit 24 and the processing unit 22 converts power from the power supply unit 24 to power suitable for the processing unit 22.
It should be understood that the number of the MEMS force sensors 21 utilized in the detection module 200 can be changed according to specific applications. The MEMS force sensors 21 can be selected to measure the forces applied on the measured points along one axis, two axes, or three axes. The processing unit 22 can be a micro control unit (MCU) or an application specific integrated circuit (ASIC).
Because the MEMS force sensors 21 can be mounted dependently without special mounting requirements and output digital signals, the detection module 200 can be easily mounted and achieve a higher precision.
Referring to
The detecting unit 31 includes a plurality of MEMS force sensors 311, each of which is adapted to measure the force the moving object applies on corresponding measured point of the measured object 41, and convert the data value of the force to digital signals, and output the digital signals to the processing unit 32.
The processing unit 32 is electrically connected to the detecting unit 31, to receive the digital signals from the detecting unit 31, and process the received digital signal to detect the motion of the moving object via the calculating of the motion analysis module 321.
The motion detection module 300 can be utilized in a dance arcade machine, and the measured object 41 is a detection board provided with four measured points each of which has a predetermined position. In one embodiment, the detecting unit 31 includes four MEMS force sensors 311 corresponding to the four measured points to detect contact on the measured point exerted by the moving object. User contact on the measured object 41 generates force on the measured points, detected by the MEMS force sensors 311, with corresponding force signals output to the processing unit 32 in real time and continuously.
The motion analysis module 321 of the processing unit 32 is programmable to evaluate contact with the measured object 41 based on force signals from the MEMS force sensors 311. For example, the analysis module 321 can determine whether a change in contact changes the data value for the detected forces. Because the MEMS force sensors 311 have high precision and fast response, the motion analysis module 321 is capable of receiving the force signals in real time and calculating motion in time, facilitating the processing unit 32 to generate instructions based on the result.
The wireless transmission unit 33 is coupled to the processing unit 32 to communicate with the processing unit 32. The power supply unit 34 supplies power for the processing unit 32 and the wireless transmission unit 33. The control unit 35 communicates with the wireless transmission unit 23 to receive the signals from the wireless transmission unit 33. In one embodiment, the control unit 35 includes a virtual-reality module 351 to display the user on a screen based on the digital signals from the wireless transmission unit 33.
It should be understood that the MEMS force sensors 311 can be selected to measure the forces applied on the measured points along one axis, two axes, or three axes. The processing unit 32 can be a MCU or an ASIC. In other embodiments, the wireless transmission unit 33 can be omitted, and the control unit 35 directly coupled to the processing unit 32.
In general, the word “module,” as used herein, refers to logic embodied in hardware or firmware, or to a collection of software instructions, written in a programming language, such as, for example, Java, C, or assembly. One or more software instructions in the modules may be embedded in firmware, such as an EPROM. It will be appreciated that modules may comprise connected logic units, such as gates and flip-flops, and may comprise programmable units, such as programmable gate arrays or processors. The modules described herein may be implemented as either software and/or hardware modules and may be stored in any type of computer-readable medium or other computer storage device.
It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the embodiments or sacrificing all of its material advantages, the examples hereinbefore descried merely being preferred or exemplary embodiments.
| Number | Date | Country | Kind |
|---|---|---|---|
| 98145414 | Dec 2009 | TW | national |
