Optical telemetry system and method for electro-mechanical switches

A system or method of verifying a new contact position of a multi-pole electro-mechanical switch having a plurality of contact positions is disclosed. The switch is caused to move to a new contact position. Power is provided to at least one light transmitter to cause the at least one light transmitter to transmit light toward a light reflective portion. A particular light detector among a plurality of light detectors that has received light from the light reflective portion is identified. The new contact position is verified based on the identification.

Not applicable.

BACKGROUND

The subject technology relates generally to electromechanical switches, and more specifically to system and method of optical telemetry for electromechanical switches.

Many telecommunications systems employ electromechanical switches to pass radio frequency (RF) signals. One application for these types of electromechanical switches is in spacecraft communications wherein an uplink RF signal may be transmitted as a downlink RF signal. These types of telecommunications systems frequently make use of a multi-pole electro-mechanical switch (e.g., a rotary switch) in which a signal provided to a motor, positioned within or without the switch, causes the switch to change its position or state.

In many of these RF switch applications, the electromechanical RF switches are remotely located, such as in an isolated telecommunications switching center or in a spacecraft. Because of the remoteness and inaccessibility of the RF switches, it is important to provide a telemetry system to monitor the status or position of each of the RF switches. In some cases, a sensor portion of the telemetry system is integrated in the same package as the RF switch being monitored to form an integrated electromechanical switch.

In conventional electromechanical switches, the sensor portion includes a number of electromechanical sensor switches where one of the sensor switches is actuated at a given position of the multi-pole electromechanical switch. For example, the sensor portion can include a combination of a magnet and magnetically actuated reed switches (the number of reed switches being equal to the number of poles of the electromechanical switch) in which as the position of the electromechanical switch is changed from a first position to a second position, the magnet moves from a first location above a first reed switch associated with the first position to a second location above a second reed switch associated with the second position. The movement of the magnet causes release (e.g., opening) of the first reed switch and actuation (e.g., closing) of the second reed switch. By monitoring the states of all the reed switches and determining which one of the switches is actuated (e.g., by monitoring their outputs), the telemetry system can determine or verify the position of the multi-pole electromechanical switch.

However, such electromechanical switch telemetry based on electromechanical sensor switches such as reed switches can fail to provide accurate indication of the RF switch position due to a failure of one of the sensor switches. The failure of the sensor switch is often attributable to electromechanical nature of the switch including foreign object debris in the plating of the contact surfaces of the switch.

SUMMARY

According to various aspects of the present disclosure, an optical telemetry system for monitoring the position of an electromechanical switch is provided. In such an optical telemetry system, optical sensors can be provided inside the electromechanical switch.

In one aspect of the disclosure, an electromechanical switch is disclosed. The electro-mechanical switch comprises a switching member having a common contact and a plurality of switch contacts. The common contact is configured to be connected to one of the plurality of switch contacts in a given switch position. The electromechanical switch further comprises a motor coupled to the switching member and configured to rotate by a predetermined angle in response to a rotation signal. The electromechanical switch further comprises a target disk coupled to the motor and configured to be rotated by the predetermined angle. Part of the surface of the target disk has a light reflective portion. The electromechanical switch further comprises at least one light transmitter disposed relative to the target disk and configured to transmit light toward the surface of the target disk having the light reflective portion. The electromechanical switch further comprises a plurality of light detectors disposed relative to the at least one light transmitter. Each of the plurality of light detectors is associated with a corresponding one of the plurality of switch contacts. At least one of the plurality of light detectors is configured to receive light reflected from the light reflective portion of the target disk for a given switch position.

In one aspect of the disclosure, a method of verifying a new contact position of a multi-pole electro-mechanical switch having a plurality of contact positions is disclosed. The method comprises causing the switch to move to a new contact position. The method further comprises providing power to at least one light transmitter to cause the at least one light transmitter to transmit light toward a light reflector. The method further comprises identifying a particular light detector among a plurality of light detectors that has received light reflected from the light reflector. The method further comprises verifying the new contact position based on the identification.

In one aspect of the disclosure, a telemetry system is disclosed. The telemetry system comprises an electromechanical switch. The electromechanical switch comprises a switching member having a plurality of contact positions. The electromechanical switch further comprises a motor coupled to the switching member. The electromechanical switch further comprises a target disk coupled to the motor and having a light reflective portion. The electromechanical switch further comprises at least one light transmitter disposed relative to the target disk and configured to transmit light toward the target disk. The electromechanical switch further comprises a plurality of light detectors disposed relative to the light detector. At least one of the plurality of light detectors is configured to receive light reflected from the light reflective portion for a given switch position. The telemetry system further comprises a control system electrically coupled to the electromechanical switch. The control system is configured to send a rotation signal to the motor to cause the switching member to move to a new contact position. The control system is further configured to provide power to the at least one light transmitter to cause the at least one light transmitter to transmit light toward a light reflector. The control system is further configured to identify a particular light detector among the plurality of light detectors that has received light reflected from the light reflector. The control system is further configured to verify the new contact position based on the identification.

DETAILED DESCRIPTION

FIG. 1is a diagram illustrating an exemplary multi-pole electromechanical switch100according to a certain aspect of the present disclosure.FIG. 2is a diagram illustrating various positions of the electromechanical switch100. In the illustrated example ofFIGS. 1 and 2, the electromechanical switch100is assumed to be a single-pole 4-throw (SP4T) switch having one common contact and 4 switch contacts. However, it will be appreciated by a person skilled in the art that various aspects of the present disclosure are applicable to other switch configurations such as single-pole multi-throw switches (e.g., SPDT or SP8T) and multi-pole multi-throw switches (e.g., DPDT or DP4T).

The electro-mechanical switch100includes RF connectors172,174A-D, a switching member160comprising a plurality of contacts, an actuator150, a motor140having an upper rotor144and a lower rotor142, a target disk130having a reflective portion132and non-reflective portions134(only 1 out of 3 shown for simplicity), and a printed circuit board (PCB)110on which optical sensors120A,120B (only 2 out of 4 shown for simplicity) are provided. The electromechanical switch100is connected to a control system601(FIG. 6) via a control cable190.

The connectors172,174A-D are internally connected to various contacts inside the switching member160. For example, asFIG. 2illustrates, the switching member160includes a common contact162, and 4 switch contacts164A-D that are internally connected to the connectors172,174A-D inside the switching member160. The motor140is configured to receive a rotation signal192from the control system601(FIG. 6) via the control cable190and rotate the actuator150and the target disk130via the upper rotor144and the lower rotor142, respectively. The actuator150is configured to rotate in response to the rotation of the motor140and cause the common contact162to break an existing connection with one of the switch contacts164A-D and establish a new connection with another of the switch contacts via mechanical or electromagnetic linkage. The motor140can be any type of an electrically controllable motor including, but are not limited to, a stepper motor and a server motor having a rotational position feedback. By providing an appropriate rotation signal (e.g., step pulses in case of a stepper motor), the motor140can be made to rotate by a predetermined angle. For example, in case of a SP4T switch, each stepper pulse rotates the upper and lower rotor142,144by 90°. In that case, in order to move from Position1(FIG. 2) to Position3(FIG. 2), the rotation pulse includes two stepper pulses, each effectuating a 90° rotation.

FIG. 3is a bottom-up (e.g., +z direction) view of the target disk130shown inFIG. 1. The target disk130includes a reflective portion or reflector132, a first non-reflective portion134, a second non-reflective portion136, and a third non-reflective portion138. The reflective portion or reflector132reflects a substantial (e.g., >50%) of incident light and may be formed from a patterned deposition of a metal film such as Al or Au film onto an opaque disk. In some embodiments, the non-reflective portions134,136, and138that comprise materials that substantially absorb or scatter incident light may be separately deposited onto the opaque disk. In other embodiments, the opaque disk itself serves as the non-reflective portions without additional depositions.

The target disk130is likewise coupled to the motor140and configured to rotate in response to the rotation of the motor140. The resulting rotation of the target disk130cause the reflective and non-reflective portions132-138to rotate with respect to the PCB110having optical sensors120A,120B,120C, and120D as shown inFIG. 4. In the illustrated example, each of the optical sensors120A-D comprises a pair of a light transmitter122A-D and a light detector124A-D. The light transmitter122A-D may be any light source such as a diode laser or an LED. The light detector124A-D may be any device that is capable of detecting light such as a photodiode, a phototransistor, or a photoresistor. In certain embodiments, each of the light transmitters (e.g.,122A) is integrated in the same package as each of the corresponding light detector (e.g.,124A), and the integrated package is installed (e.g., soldered) on the PCB110. In other embodiments, the light transmitters122A-D and the light detectors are individual components separately installed on the PCB110. The PCB110and the target disk130are positioned in close proximity to prevent a light spillover to adjacent sensors, e.g., to reduce or eliminate a portion of light transmitted from a light transmitter (e.g.,122A) and reflected from a reflective portion (e.g.,132) from reaching a light detector (e.g.,124B) that is not associated with the light transmitter. To further prevent such a light spillover, the optical sensor (e.g.,120A) may have a side wall129A as shown inFIG. 1to limit the angular distribution of the transmitted light.

In certain embodiments, the PCB110includes detector circuits112having inputs connected to and configured to receive a signal (e.g., a pulse) from one of the light detectors124A-D indicative of reception of light reflected from the reflective portion132and to provide a latched output upon receiving such a signal. Outputs of the detector circuits112may be polled by the control system601(FIG. 6) at a later time. In some embodiments, the latchable detector circuits112are formed in a single integrated package. In other embodiments, the detector circuits112are part of the light detectors. In yet other embodiments, the detector circuits112are part of the control system601(FIG. 6).

Operation of the electromechanical switch100is now described with reference to a flowchart inFIG. 5illustrating an exemplary process500of operation of a telemetry system including an electromechanical switch such as the electromechanical switch100and also withFIG. 6which is a block diagram of an exemplary control system601that controls the operation of the electromechanical switch100. For the purpose of illustration only, it is now assumed that initially (prior to the operation510), the electromechanical switch100is in Position2(FIG. 2) in which the common contact162is connected to the switch contact164B, and the reflective potion132is positioned directly over the optical sensor120B. It is also assumed that that the control system601desires the electromechanical switch100to move to Position1in which the common contact162is connected to the switch contact164A, and the reflective portion132is positioned directly over the optical sensor120A as shown inFIG. 1.

The process500begins at start state and proceeds to an operation510, in which a rotation signal192is sent from the control system601to the motor140. As described above, the motor140may be a stepper motor, and the rotation signal192may comprise one or more stepper pulses configured to rotate the upper and lower rotors144,142and hence the actuator150and the target disk130coupled to the upper and lower rotors144,142by a predetermined rotation angle. In this case, the control system601can rotate the motor140either +270° by sending a rotation signal comprising three stepper pulses or −90° by sending an alternative rotation signal comprising one reverse stepper pulse. In either case, the electromechanical switch100moves to Position1as shown inFIG. 1.

The process500proceeds to an operation520, in which detector circuits112associated with the light detectors124A-D (FIG. 4) are unlatched. As described above with respect toFIG. 4, the detector circuits112include inputs connected to and configured to receive a signal (e.g., a pulse) from one of the light detectors124A-D indicative of reception of light reflected from the reflective portion132and to provide a latched output upon receiving such a signal. The unlatching at the state520clears any latched outputs from previous switching event so that a new latched output can be provided upon receiving a signal from one of the light detectors124A-D.

The process500proceeds to an operation530, in which power is provided to light transmitters/sources122A-D. For example, the light transmitters (e.g., LEDs) can receive electrical currents from the control system601via the control cable190. Alternatively, the PCB110may include a switch that is configured to receive a switch control signal from the control system601via the control cable190and to provide power to the LEDs via the switch. Upon receiving the power, the light transmitters122A-D transmit light toward the target disk130as shown inFIG. 1. Also as shown inFIG. 1, a light beam123A transmitted by the light transmitter122A is reflected by the reflective portion132of the target130to form a reflected light beam125A, while a light beam123B transmitted by the light transmitter122B is absorbed or scattered by the non-reflective portion134of the target disk130.

The process500proceeds to an operation540, in which light reflected from the reflective portion132(e.g., the reflected light beam125A) is received by the light detector124A; and then to an operation550, in which the detector circuit associated with the light detector124A that has received the reflected light is latched. After the latching, the power provided to the light transmitters122A-D may be turned off to conserve power and reduced heating. The process500proceeds to an operation570, in which the control system601polls the outputs of the detector circuits112(FIG. 4) to determine which of the light detectors124A-D has received light reflected from the reflective portion132of the target disk130. This polling operation may happen several times before another activation takes place. The process500then proceeds to an operation580, in which the new switch position (Position1in this case) is determined or verified based on the polled information.

It shall be appreciated by those skilled in the art in view of the present disclosure that the hardware and process arrangements discussed above are provided for the purpose of illustration only, and other arrangements may be employed without departing from the scope of the present disclosure. For example, in certain embodiments, there may not be detector circuits interposed between the light detectors124A-D and the control system601. Instead, the control system601may be configured to monitor the outputs of the light detectors122A-D directly after providing power to the light transmitters122A-D. For example, the outputs of the light detectors124A-D, instead of being connected to any detector circuits, may be connected to interrupt inputs of a processor in a processing system602of the control system601(FIG. 6). An application program running in the processing system may detect a signal received at one of the interrupt inputs. In such an embodiment, the steps550and560ofFIG. 5may not be present.

As another example of alternative arrangements, instead of providing separate light transmitters122A-D as shown inFIG. 4, there may be only one light transmitter positioned at the center of the PCB110that is configured to transmit, a light beam having a wide beam pattern toward the target disk130. Only a portion of the wide light beam reflected from the reflective portion132is received by one of the light detectors124A-D. As yet another example of alternative arrangements, the target disk130may have one non-reflective portion and a plurality of reflective portions, and the non-reflective potion may be positioned above the optical sensor associated with the new contact position. In such an embodiment, the new switch position is determined or verified by identifying a light detector that did not receive reflected light.

As discussed briefly above,FIG. 6is a block diagram of an exemplary control system601that controls the operation of the electromechanical switch100. The control system601, which may be, for example, a desktop computer, a laptop computer or another type of computing device, includes a processing system602. The processing system602is capable of communication with a receiver606and a transmitter609through a bus604or other structures or devices. It should be understood that communication means other than busses can be utilized with the disclosed configurations. The processing system602can generate audio, video, multimedia, and/or other types of data to be provided to the transmitter609for communication. In addition, audio, video, multimedia, and/or other types of data can be received at the receiver606, and processed by the processing system602.

The processing system602may include a general-purpose processor or a specific-purpose processor for executing instructions and may further include a machine-readable medium619, such as a volatile or non-volatile memory, for storing data and/or instructions for software programs. The instructions, which may be stored in a machine-readable medium610and/or619, may be executed by the processing system602to control and manage access to the various networks, as well as provide other communication and processing functions. The instructions may also include instructions executed by the processing system602for various user interface devices, such as a display612and a keypad614. The processing system602may include an input port622and an output port624. Each of the input port622and the output port624may include one or more ports. The input port622and the output port624may be the same port (e.g., a bi-directional port) or may be different ports.

The processing system602may be implemented using software, hardware, or a combination of both. By way of example, the processing system602may be implemented with one or more processors. A processor may be a general-purpose microprocessor, a microcontroller, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a Programmable Logic Device (PLD), a controller, a state machine, gated logic, discrete hardware components, or any other suitable device that can perform calculations or other manipulations of information.

A machine-readable medium can be one or more machine-readable media. Software shall be construed broadly to mean instructions, data, or any combination thereof, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Instructions may include code (e.g., in source code format, binary code format, executable code format, or any other suitable format of code).

Machine-readable media (e.g.,619) may include storage integrated into a processing system, such as might be the case with an ASIC. Machine-readable media (e.g.,610) may also include storage external to a processing system, such as a Random Access Memory (RAM), a flash memory, a Read Only Memory (ROM), a Programmable Read-Only Memory (PROM), an Erasable PROM (EPROM), registers, a hard disk, a removable disk, a CD-ROM, a DVD, or any other suitable storage device. In addition, machine-readable media may include a transmission line or a carrier wave that encodes a data signal. Those skilled in the art will recognize how best to implement the described functionality for the processing system602. According to one aspect of the disclosure, a machine-readable medium is a computer-readable medium encoded or stored with instructions and is a computing element, which defines structural and functional interrelationships between the instructions and the rest of the system, which permit the instructions' functionality to be realized. Instructions can be, for example, a computer program including code.

An interface616may be any type of interface and may reside between any of the components shown inFIG. 6. An interface616may also be, for example, an interface to the outside world (e.g., an Internet network interface). A functionality implemented in a processing system602may be implemented in a portion of a receiver606, a portion of a transmitter609, a portion of a machine-readable medium610, a portion of a display612, a portion of a keypad614, or a portion of an interface616, and vice versa. A transceiver block607may represent, for example, a wired or wireless computer interface between the system601and the measurement device690.

Various aspects of the subject technology can be implemented in the system601with respect to various components of the electromechanical switch100. For example, the processing system602can determine a degree of rotation to arrive at a new switch position and generate or cause a motor controller630to generate a rotation signal192configured to rotate the motor140inside the electromechanical switch100by the determined degree of rotation. The processing system602can also provide or cause a LED controller640to provide power194to the light transmitters122A-D inside the electromechanical switch100. The processing system602can also poll the outputs of detector circuits inside or outside the electromechanical switch100to determine which of the light detectors124A-D has received reflected light and also from that information determine or verify the new position of the electromechanical switch100. A verification record indicating whether the new position for the electromechanical switch100has been achieved after each rotation and verification process such as the process500can be kept in the machine-readable medium619,610. A series of switch positions to be applied to the electro-mechanical switch100may also be stored in the machine-readable medium619,610.

A phrase such as an “aspect” does not imply that such aspect is essential to the subject technology or that such aspect applies to all configurations of the subject technology. A disclosure relating to an aspect may apply to all configurations, or one or more configurations. A phrase such as an aspect may refer to one or more aspects and vice versa. A phrase such as an “embodiment” does not imply that such embodiment is essential to the subject technology or that such embodiment applies to all configurations of the subject technology. A disclosure relating to an embodiment may apply to all embodiments, or one or more embodiments. A phrase such an embodiment may refer to one or more embodiments and vice versa.