INCORPORATION BY REFERENCE

An Application Data Sheet is filed concurrently with this specification as part of the present application. Each application that the present application claims benefit of or priority to as identified in the concurrently filed Application Data Sheet is incorporated by reference herein in its entirety and for all purposes. This application is also related to the following: U.S. Pat. No. 8,254,013, issued Aug. 28, 2012; U.S. patent application Ser. No. 14/951,410 filed Nov. 24, 2015; U.S. patent application Ser. No. 13/326,168 filed Dec. 14, 2011; U.S. patent application Ser. No. 13/449,235 filed Apr. 17, 2012; U.S. patent application Ser. No. 13/449,248 filed Apr. 17, 2012; U.S. patent application Ser. No. 13/449,251 filed Apr. 17, 2012; U.S. patent application Ser. No. 13/462,725, filed May 2, 2012; U.S. patent application Ser. No. 13/772,969 filed Feb. 21, 2013; U.S. patent application Ser. No. 14/443,353, filed May 15, 2015. U.S. patent application Ser. No. 15/123,069 filed Sep. 1, 2016; International Patent Application No. PCT/US16/55709, filed Oct. 6, 2018; U.S. patent application Ser. No. 15/334,832, filed Oct. 26, 2016; U.S. patent application Ser. No. 15/334,835, filed Oct. 26, 2016; U.S. patent application Ser. No. 15/320,725 filed Dec. 20, 2016; International Patent Application No. PCT/US17/20805, filed Mar. 3, 2017; International Patent Application No. PCT/US17/28443, filed Apr. 19, 2017; International Patent Application No. PCT/US17/31106, filed on May 4, 2017; U.S. patent application Ser. No. 15/529,677 filed May 25, 2017; U.S. patent application Ser. No. 15/534,175 filed Jun. 8, 2017; International Patent Application No. PCT/US17/62634, filed on Nov. 20, 2017; International Patent Application No. PCT/US17/66486, filed Dec. 14, 2017; U.S. Pat. No. 9,885,935, issued Feb. 6, 2018; International Patent application No. PCT/US18/29460, filed May 25, 2018; and International Patent Application No. PCT/US18/29476, filed May 25, 2018. Each of these related applications is also incorporated herein by reference in its entirety and for all purposes.

FIELD

The embodiments disclosed herein relate generally to detecting security events in or near a building, the building including tintable “smart windows”, more particularly to smart windows that are used to detect and, in some instances, respond to, the security events.

BACKGROUND

Optically switchable windows, sometimes referred to as “smart windows,” exhibit a controllable and reversible change in an optical property when appropriately stimulated by, for example, a voltage change. The optical property is typically color, transmittance, absorbance, and/or reflectance. Electrochromic devices are sometimes used in optically switchable windows. One well-known electrochromic material, for example, is tungsten oxide (WO3). Tungsten oxide is a cathodic electrochromic material in which a coloration transition, transparent to blue, occurs by electrochemical reduction.

Electrically switchable windows, sometimes referred to as “smart windows”, whether electrochromic or otherwise, may be used in buildings to control transmission of solar energy. Switchable windows may be manually or automatically tinted and cleared to reduce energy consumption, by heating, air conditioning and/or lighting systems, while maintaining occupant comfort.

Windows are located on the skin of a building and are common targets for potential intruders, as they are often the weakest portion of a building's skin. When protecting against theft and other unwanted forms of intrusion, windows are generally a primary concern as they are easily broken. Improved techniques for detecting and responding to such security events are desirable, particularly techniques that exploit the networked aspects of the smart windows.

SUMMARY

According to some embodiments, a method of detecting a security-related event in an optically switchable window includes: (a) measuring a current or voltage of an optically switchable device of the optically switchable window without perturbing a process of driving a transition between optical states and/or maintaining an end optical state of the optically switchable window; (b) evaluating the current or voltage measured in (a) to determine whether the current or voltage measured in (a) indicates that the optically switchable window is broken or damaged; and (c) in response to detecting the response in (b), performing a security action.

In some examples, measuring the current or voltage of the optically switchable device may be performed while the optically switchable window is undergoing the transition from a first tint state to a second tint state.

In some examples, measuring the current or voltage of the optically switchable device may include measuring an open circuit voltage of the optically switchable device. In some examples, measuring the open circuit voltage of the optically switchable device may be performed while the optically switchable window is undergoing the transition from a first tint state to a second tint state.

In some examples, evaluating the current or voltage measured in (a) may include comparing the current or voltage measured in (a) against an expected current or voltage for the process of driving the transition between optical states and/or maintaining the end optical state of the optically switchable window. In some examples, the expected current or voltage may be a previously measured current or voltage for the process of driving the transition between optical states and/or maintaining the end optical state of the optically switchable window.

In some examples, measuring the current or voltage of the optically switchable device may be performed while the optically switchable window is in the end optical state.

In some examples, measuring the current or voltage of the optically switchable device may include measuring a leakage current of the optically switchable device and evaluating the current or voltage measured in (a) may include comparing the leakage current against an expected leakage current of the optically switchable device.

According to some embodiments, a security system includes one or more interfaces for receiving sensed values for an optically switchable device of an optically switchable window; and one or more processors and memory configured to perform a method of detecting a security-related event in the optically switchable window, the method including: (a) applying a perturbation to an optically switchable device of the optically switchable window; (b) detecting a response to the perturbation that indicates that the optically switchable window is broken or damaged; and (c) in response to detecting the response in (b), performing a security action.

In some examples, the applying the perturbation may include applying a perturbing voltage or a perturbing current to the optically switchable window during a tint transition of the optically switchable window; and the perturbing voltage or the perturbing current may not be part of a tint transition drive cycle for the optically switchable window.

In some examples, the perturbation may include a voltage ramp, a current ramp, or a constant voltage to the optically switchable device, and detecting the response to the perturbation may include at least one of: detecting a current produced by the optically switchable device in response to the perturbation; or measuring an open circuit voltage of the optically switchable device after application of the perturbation. In some examples, a slope of at least one of the voltage ramp and the current ramp may be a parameter set by one or more of a window controller, a network controller, and a master controller based on one or both of a size of the window and the external temperature.

In some examples, applying the perturbation in (a) may include repeatedly applying the perturbation while the optically switchable device is in an end tint state or applying a square wave or saw tooth wave to the optically switchable device.

In some examples, the perturbation may include an oscillating current or voltage; and detecting a response to the perturbation may include detecting a frequency response produced by the optically switchable device in response to the oscillating current or voltage. In some examples, detecting the response to the perturbation may include determining that frequency absorption of the optically switchable device deviates from an expected frequency absorption.

In some examples, performing the security action may include one or more of: displaying an alert on a local or a remote device; applying a square wave or saw tooth wave to the optically switchable device; adjusting lighting in a room proximate the optically switchable window; locking a door in a room proximate the optically switchable window; adjusting a tint state of a tintable window proximate the optically switchable window; lighting a display registered with the optically switchable window; and lighting the display with a flashing light pattern on the display.

In some examples, the optically switchable device may be an electrochromic device.

In some examples, detecting the response to the perturbation may include one or both of: evaluating the absolute value of a measured current; and evaluating a change, over a period of time, in a value of the measured current. In some examples, evaluating the absolute value of the measured current may include comparing the absolute value of the measured current with a specified value.

According to some embodiments, a method of detecting a security-related event includes (a) measuring one or more of a current, a voltage and a charge count (Q) of an optically switchable window; (b) determining whether the optically switchable window is broken or damaged using one or more of the current, the voltage and the charge count measured in (a); and (c) in response to determining that the optically switchable window is broken or damaged, performing a security action and/or an alert action.

In some examples, (a) may be performed while the optically switchable window is undergoing a transition from a first tint state to a second tint state.

In some examples, the measured voltage may be an open circuit voltage of the optically switchable window.

In some examples, measuring the one or more of current, voltage and Q may be performed without visibly perturbing an apparent optical state of the optically switchable window.

In some examples, measuring the one or more of current, voltage and Q may be performed over a period of one minute or less and/or at a first regular interval.

In some examples, measuring the one or more of current, voltage and Q may be performed without perturbing a process of driving a transition of the optically switchable window between optical states.

In some examples, the method may further include always applying a non-zero hold and/or drive voltage to the optically switchable window.

In some examples, determining whether the optically switchable window is broken or damaged may include measuring the current and, when the measured current is less than a specified value, measuring one or both of the voltage and Q. In some examples, determining whether the optically switchable window is broken or damaged may include determining that the optically switchable window is not broken or damaged when at least one of the measured voltage and Q exceeds a respective threshold value. In some examples, the respective threshold values may be selectable by one or more of a window controller, a network controller, and a master controller; at least one of the window controller, the network controller, and the master controller may select the threshold value as VOC Targetduring some operations and select the threshold value as 1/n*VOC Targetduring some other operations; and n is at least 2 during some other operations.

In some examples, the alert action may be selected from the group consisting of: ordering a replacement for the optically switchable window, notifying a window supplier to ship a replacement optically switchable window, notifying an optically switchable window repair technician to repair the window, notifying a manager of a building in which the optically switchable window is installed that there is an issue related to the window, notifying monitoring personnel to open a service case/record, and generating a return merchandise authorization (RMA) order; and the alert action may be performed automatically and/or without interaction of a human.

These and other features and embodiments will be described in more detail below with reference to the drawings.

