Patent Description:
HVAC systems installed in buildings or other installations are expected to achieve high standards of safety and reliability. HVAC systems also contribute to a building's fire safety. Monitoring and testing of the system is important for maintaining reliability and safety standards. Laws often require regular checks to be carried out on the system's performance.

One aspect of monitoring and testing a HVAC system concerns the functionality of electronically controlled flow regulators, e.g. valves and dampers, that regulate flow of fluids (gases and/or liquids, such as air and/or water). The efficiency and safety of the system may depend on the regulators functioning correctly. Fire dampers are examples of electronically controlled regulators intended to close off air passages in the HVAC system in the event of a fire, to avoid fire and smoke spreading in a building via the HVAC system. Smoke control dampers are examples of electronically controlled regulators similarly intended to open to allow extraction of smoke and fumes through a ventilation duct. Testing can verify whether such dampers do function as required, close tightly and open properly. Other electronically controlled regulators are also important to everyday ventilation, heating and air conditioning.

When a malfunction occurs in a HVAC flow regulator, diagnosing the cause is complicated, especially when the regulator is assembled from multiple operating parts or units that interact, such as flow-controlling parts in the fluid path, electro-mechanical parts, and operating sensors. Since different component units of the regulator are often the responsibility of, or need the skills of, different specialists, corrective action can only be carried out once it is determined properly where the fault lies. The problem is further exacerbated if the electronically controlled flow regulators are placed in locations making physical access to the regulators difficult, which is not infrequent.

If checks are carried out relatively infrequently (for example, every <NUM> or <NUM> months), a malfunction may occur that is not detectable for a long time, potentially creating a hidden safety hazard. In addition to solving problems for regulators that have malfunctioned, a further technical challenge relates to identifying electronically controlled regulators that present risk of failing in the future. Diagnosing potential future faults, and associated causes for the potential faults, especially in regulators constructed from multiple component units, adds further technical complexity.

It would be desirable to address and/or mitigate one or more of the issues described above.

Aspects of the invention are identified in the claims.

A first aspect of the invention provides a method of controlling an HVAC system comprising:.

wherein the method comprises the steps of:.

wherein it is distinguished in step iv. between an actual or forthcoming malfunction of:.

characterized in that the step of determining an actual or forthcoming malfunction comprises diagnosing a forthcoming malfunction.

Such a method permits self-diagnosis of the malfunction (actual or forthcoming) by the controller. By distinguishing between a malfunction of the actuator or the flow regulator, the task of corrective action to repair or mitigate the malfunction is made much easier. Depending on whether the fault is caused by the flow regulator, or by the actuator, the appropriate specialist (e.g. a person and/or a machine and/or a robot) for the respective unit can repair, replace, or perform other maintenance on the appropriate unit, and/or record the fault in appropriate technical documentation.

This may be especially, but not exclusively, useful when the flow regulator and the actuator operate together as an integrated unit, but originate from different manufacturers, for example, in an OEM (Original Equipment Manufacturer) production process. The flow regulator and the actuator may then be the responsibility of, or need the skills of, different specialists after manufacture.

The ability to self-diagnose actual and forthcoming malfunctions can contribute significantly to the safety (e.g. fire safety) of a building in which the HVAC system is installed. The performance of the actuator and the flow regulator can be monitored as frequently as desired, e.g. in parallel with normal operation in some embodiments. Also, a forthcoming malfunction can be diagnosed and remediated in advance. A forthcoming malfunction may be a predicted malfunction, for example, corresponding to increased risk or likelihood that malfunction may occur even though the actuator and/or the flow regulator remain functioning at the time of diagnosis. Detection of a forthcoming malfunction is significant for enabling predictive maintenance adapted to the individual actuator and/or flow regulator, and which may supplement or be used instead of just a regular maintenance schedule.

A yet further advantage of self-diagnosis is that it may provide an operator with important information as to whether the HVAC system is correctly set-up and/or dimensioned. For example, the information may enable the operator to optimise the HVAC system towards better cost structure and/or desired reliability.

As used herein, the term flow regulator may be any device for adjusting an orifice to regulate fluid flow in a flow path, for example, a damper, a flap, or a valve. The flow regulator may be of type having two discrete states, for example, open and closed; or the flow regulator may of a type having three or more discrete states, for example, open, closed and one or more intermediate states; or the flow regulator may be of a type that defines a continuously variable orifice size, for example continuously variable between fully open and fully closed. The actuatable part of the flow regulator may, for example, be any movable element such as a damper blade, a valve ball, valve plug, valve flap, etc..

In some embodiments, a lever mechanism may operatively connect the output member of the actuator, and the flow regulator. Other types of mechanisms, or direct or indirect couplings between the actuator and the flow regulator may alternatively be used, as desired.

In some embodiments, the actual or forthcoming malfunction of the flow regulator is chosen from a group comprising, preferably consisting of, a worn-out bearing; a deficiently fixed bearing; a worn-out gasket; a distorted damper sleeve; a broken damper blade; blockage of the actuatable part of the flow regulator, for example, caused by a foreign object or caused by excessive contamination of, or excessive pollution of, the medium in the flow path.

Additionally or alternatively, in some embodiments, the actual or forthcoming malfunction of the actuator is chosen from a group comprising, preferably consisting of, a defective or worn out bearing for the output member; defective or worn out output gearing; defective actuator mounting; defective motor; defective motor bearing; defective connection to the flow regulator; non-attached connection to the flow regulator; defective return spring; defective supercapacitor for powering actuation to a predetermined position in the event of power loss; defective battery for powering actuation to a predetermined position in the event of power loss; defective electronic circuitry.

By way of example, a non-attached connection state with respect to the flow regulator may occur if the actuator and flow regulator are incorrectly assembled during manufacture or installation. Detecting such a malfunction may be important when the flow regulator and the actuator are integrated in an HVAC system, as described later. A non-attached connection state may be diagnosed by defining a predetermined travel range of movement for the flow regulator, and monitoring whether the flow-regulator in use realises the travel range and/or whether the actuator measures movement beyond the travel range. The travel range may be sensed by, for example, one or more position sensors, or end-stop sensors, or monitoring other parameters such as load or current when the flow regulator is actuated to reach an end-stop position. In one example, the flow regulator may be mechanically restricted (e.g. by end-stops) to a travel range of <NUM>° to <NUM>°. Should the actuator measure, from the output member, an angle outside the restricted range (e.g. less than <NUM>° or more than <NUM>°), this may indicate that output member of the actuator is not attached operatively to the flow regulator. It is also possible to determine the travel range of the flow regular indirectly, for example, by: (i) determining an angular distance the motor has travelled (e.g. be means of a position sensor or, sensorless deduction by the motor controller); and (ii) calculating the corresponding travel range of the flow regulator using a known gear ratio.

In addition to the sensors associated with the actuator, in some embodiments, the HVAC system further comprises one or more sensors chosen from the group comprising, preferably consisting of, temperature sensors; humidity sensors; flow sensors; air speed sensors; air/fluid quality/pollution sensors; viscosity sensors; concentration sensors; optical sensors (for example, CCD sensors or cameras). By way of example, optical sensors may monitor the operating state and/or condition of the flow regulator, and/or may monitor pollution and/or contamination of the medium in the flow path).

Such sensors can provide additional information to the controller relating to temporal parameters that may influence operation characteristics of the flow regulator and/or the actuator. For example, temperature and/or pressure and/or fluid contamination can influence the manner in which the regulator operates. Providing such information to the controller may facilitate the controller compensating for such parameter variations in determining an actual or forthcoming malfunction.

Additionally or alternatively, in some embodiments, in step iii. , the actual or forthcoming malfunction is determined while taking into account as a corrective compensation:.

Additionally or alternatively, in some embodiments, historical information may be recorded to judge a service age of the flow regulator and/or the actuator. For example, in some embodiments, a cycle number and/or a count of direction changes and/or an aggregate operating time and/or an aggregate travel of the flow regulator; and/or a cycle number and/or a count of direction changes and/or an aggregate operating time and/or an aggregate travel of the actuator is recorded.

A variety of techniques may be used to determine and discriminate actual and forthcoming malfunctions.

is used to determine an actual or forthcoming malfunction.

Use of a reference torque curve or current curve of the actuator per se without the flow regulator can provide useful baseline information to the controller about the characteristics of just the actuator without any influence of the flow regulator. This may facilitate identifying and discriminating malfunctions (actual and/or forthcoming) associated with the actuator.

Similarly, use of a reference curve associated with the flow regulator per se without the actuator can provide useful baseline information to the controller about the characteristics of the just the flow regulator without any influence of the actuator. This may facilitate identifying and discrimination malfunctions (actual and/or forthcoming) associated with the flow regulator.

Similarly, a reference torque curve or current curve of the actuator when operatively connected with the flow regulator provides baseline information of how both units perform together, which is the operating condition that will normally be evaluated by the method.

Additionally or alternatively, in some embodiments, in step ii.

References above to the actuator being released refer to actuators of a type configured, in response to power loss, to move the output member to a predetermined operative position. The predetermined position may, for example, correspond to an open position of the flow regulator, a closed position of the flow regulator, or some intermediate position. Upon power loss, the actuator is said to be being released, and the output member is driven to the predetermined position. For example, the actuator may comprise a spring (e.g. a return spring) to drive movement, or the actuator may comprise a reserve power source, for example, a supercapacitor or a battery, to provide reserve power to perform the actuation.

References above to a derivative refer to performing a mathematical derivative function indicative of rate of change (e.g. a differentiation). References above to an integral refer to performing a mathematical integration function indicative of accumulation or aggregation. References herein to maximum values of parameters or calculations may generally refer to maximum magnitudes in the case where directionality of movement of the actuator and/or flow regulator may introduce negative values as a result of a directional frame of reference.

By way of example, the speed of movement of the actuator and/or the flow regulator during actuation may provide insight into whether the actuator is overloaded. The actuator may operate at a predetermined or expected speed or within a certain speed window, for example, motor rotation of about <NUM> RPM. If the actuator deviates from the expected speed by more than a set amount, this may indicate a malfunction, for example, overloading of the actuator for some reason. Speed detection can provide additional or alternative performance information compared to torque/current information. Speed may, for example, be detected or associated with voltage across a motor, or speed may be measured by detecting actuator position changes with respect to time, for example, by counting a rate of generated pulses from a rotation sensor, or by a mathematical derivative of position-related signals.

Also by way of example, detection of the position of the output member at an extremity of a range of movement of the flow regulator, may be used in the detection of a non-attached connection state between the actuator and the flow regulator, as described above. It may also be useful for the detection of abnormal blockage or other obstruction of the actual range of movement of the flow regulator, in use. The position at which the flow regulator stops when the open or closed position is expected, may be used to detect whether the travel range is impeded compared to an expected travel range, for example, should the flow channel be blocked by a foreign object.

Additionally or alternatively, in some embodiments, in step iv. , hysteresis of the actuator and/or lever mechanism (if present) is used to distinguish between a malfunction of the actuator and the flow regulator. Hysteresis can provide a useful tool for discrimination, because hysteresis is a feature principally of parts other than the flow regulator (namely, for example, the actuator and/or lever mechanism (if present)). The actuator and/or lever mechanism may even be designed to have exaggerated hysteresis, if desired, to provide a greater window for detecting fault parameters associated parts other than the flow regulator.

The controller may optionally be a device that is local to and/or associated uniquely with the respective actuator. For example, the controller may be provided with the actuator, and/or integrated with the actuator, and/or contained within the same housing as the actuator. Such a local controller may optionally be in operative data communication with a system- or group- controller with control for multiple flow regulators.

Alternatively, the first-mentioned controller may be a controller that is operatively connected to and/or in operative communication with respective actuators for multiple flow regulators, for controlling multiple flow regulators according to the method described herein.

A closely related second aspect of the invention provides a method of setting-up an HVAC system, optionally for operation according to any of the method steps of the first aspect, the method wherein the HVAC comprises:.

wherein it is distinguished in step v. between an actual or forthcoming malfunction of:.

Optionally, the method further comprises step.

In any of the above aspects, the method may expressly include distinguishing between a forthcoming malfunction and an actual malfunction in the determining and/or indicating steps.

In some embodiments, the step of determining an actual or forthcoming malfunction my comprise diagnosing an actual malfunction. Additionally or alternatively, the step of determining an actual or forthcoming malfunction may comprise diagnosing both actual and forthcoming malfunctions (e.g. diagnosing amongst both actual and forthcoming malfunctions).

In some embodiments, the step of determining an actual or forthcoming malfunction comprises:.

Additionally or alternatively, the step of indicating the actual or forthcoming malfunction can comprise distinguishing between an actual malfunction and a forthcoming malfunction.

A closely related third aspect of the disclosure not forming part of the claimed invention may relate to providing an HVAC flow regulator actuator as a unit that is useful for manufacturers to incorporate into or with an HVAC fluid flow regulator, and optionally provides functionality for any of the methods described above.

Accordingly, a third aspect of the disclosure provides a method comprising:.

With this method, the controller may register information necessary for the controller subsequently to use for determining an actual or forthcoming malfunction. Optionally, the information may facilitate distinguishing between a malfunction (actual or forthcoming) of: the actuator unit; and the flow regulator.

The method may further comprise operating the controller to register and/or record information about operating characteristics of the actuator and the flow regulator before and/or after installation into a HVAC system, based at least on signals from at least one of the one or more sensors. Such a further step, if used, may replace and/or update the information about the operating characteristics of the actuator and the flow regulator, to reflect changes once in situ in the HVAC system.

Preferably, the method may further comprise:.

wherein the step of determining comprises distinguishing between an actual or forthcoming malfunction of: the actuator; and the flow regulator.

Non-limiting embodiments of the disclosure are now described, by way of example only, with reference to the accompanying drawings. The same reference numerals are used to denote corresponding features, whether or not described in detail.

Referring to <FIG>, at least one electronically controlled flow control device <NUM> is shown as part of an HVAC system <NUM>, for controlling fluid flow within a fluid path of the HVAC system. To avoid cluttering the diagram, <FIG> does not show the fluid path or other details of the HVAC system <NUM>, only the features relevant to understanding the present disclosure. Preferably, plural devices <NUM> are provided. The fluid may be liquid and/or gas. Example liquids may include water and/or glycerol. Example gases include air.

In some of the embodiments, the device <NUM> may be, or is illustrated in the form of, a fire damper. As explained above, a fire damper is a safety device installed in an HVAC ventilation passage. In the event of a fire, the fire damper closes to seal off the passage, and avoid fire and smoke spreading via the HVAC system. However, references herein to fire dampers are merely by way of example, and are to be understood as also extending to other types of fluid control device <NUM>, for example but not limited to, smoke control dampers.

Each device <NUM> may generally comprise a flow regulator <NUM>. The flow regulator <NUM> may be any device for adjusting an orifice through which fluid flows, for example, a damper, a flap, a valve, etc. The flow regulator <NUM> comprises an actuatable element <NUM> in the fluid path, for example, in the form of one more damper blades, a valve ball, valve plug, valve flap, etc..

Each device <NUM> may further comprise an electro-mechanical actuator <NUM> associated with the flow regulator <NUM> for actuating physical movement of the regulator <NUM>. The actuator <NUM> may comprise an electric motor <NUM> or other primary driver driving a movable output member <NUM> (shown merely schematically in <FIG>). Optionally, a transmission <NUM>, e.g. a geared transmission, couples a rotor of the motor <NUM> to the output member <NUM>. In one example, the output member <NUM> comprises a rotary member that is movable about an axis through a range of about <NUM>°.

The output member <NUM> is coupled directly or indirectly to the actuatable element <NUM> of the flow regulator <NUM>. In some embodiments, a lever mechanism <NUM> operatively links the output member <NUM> to the actuatable element <NUM>, but other types of mechanism, or direct or indirect couplings may alternatively be used as desired.

The actuator <NUM> may optionally further comprise a self-positioning device <NUM> for setting or returning the output member <NUM>, and hence the flow regulator <NUM>, to a predetermined reference position when power is removed from the device <NUM>. For example, the reference position may be a fully closed position, or a fully open position. In some embodiments, the device <NUM> may comprise a mechanical energy storage device, such as a spring, that urges the output member <NUM> to the reference position. In other embodiments, the device <NUM> may comprise an electrical energy storage device, such as a battery or a super-capacitor, for providing reserve power to the actuator <NUM> to move automatically to the predetermined reference position.

The actuator <NUM> further comprises a controller <NUM> for driving the motor <NUM> to effect instructed movements of the regulator. The controller <NUM> also receives signals from one or more sensors <NUM> associated with the actuator <NUM>, optionally associated with the motor <NUM>. Sensing parameters at the motor <NUM> may be technically easier to implement. The sensors <NUM> may include one or more chosen from the group consisting of load sensors, force sensors, torque sensors, current sensors (I), voltage sensors (V), power sensors, speed sensors, position sensors (Pos) and temperature sensors (°T).

The sensors <NUM> may be physical sensors for directly sensing a parameter, and/or virtual sensors for deriving a value of a sensed parameter from other measurements. For example, a position sensor may derive a calculated position from an aggregate of position increments sensed by an increment sensor. A position of the output member <NUM> may also be calculated from an equivalent position of the motor rotor shaft by taking into account hysteresis or backlash in the transmission <NUM>. For example, hysteresis may account for about <NUM>° of position rotation. An operating range of <NUM>-<NUM>° determined at the rotor shaft may correspond to actual movement of the output member <NUM> in a range of <NUM>-<NUM>°. The initial <NUM>° of rotor motion is lost in hysteresis. The remaining range of <NUM>-<NUM>° determined at the rotor shaft thus corresponds to the <NUM>-<NUM>° movement of the movable output member <NUM>.

Depending on the motor <NUM>, and for example a vector controlled motor, it may also be possible to derive position and/or torque measurements from signals induced by spatial magnetic conductivity fluctuations in the motor <NUM>. Such a technique is described, for example, in <CIT>.

The controller <NUM> may also receive signals from one or more external sensors <NUM>. The external sensor(s) <NUM> may, for example, be associated with the flow regulator <NUM>, or with a different part of the HVAC system, or with the building or other installation in which the HVAC system is implemented. The external sensor(s) <NUM> may, for example, sense fluid flow, fluid speed, fluid pressure in the fluid path, and/or temperature, and/or a degree of contamination or pollution of the fluid in the fluid path, and/or an actual operating position of the actuatable element <NUM>.

The sensors <NUM> (and <NUM>) may be of one or more different types including, for example, optical sensors, sonic sensors, and magnetic sensors.

The flow control device <NUM> is responsive to commands from a system controller <NUM> with which the or each control device <NUM> is in operative communication via a communication channel, which may be wired and/or optical and/or wireless.

Also illustrated in <FIG> is a remote data processing system <NUM>, which may be in operative communication with the actuator controller <NUM> and/or the HVAC system controller <NUM>, optionally via portable apparatus <NUM> (described later) or via one or more communication channels independent of portable apparatus <NUM>. The communication may, for example, be via an internet address and/or internet communication protocol, or other network or direct communication. The remote data processing system <NUM> may be a so-called cloud system or service. The connection may be permanent or it may be occasional, for example, on-demand. The connection may be wired, and/or optical and/or wireless.

A feature of this embodiment is the ability to automatically diagnose a malfunction of the device <NUM>, whether an actual or forthcoming malfunction of the device <NUM>, based on the signals sensed by the sensors <NUM> (and optionally <NUM>). The diagnosis may also include distinguishing whether the malfunction (actual or forthcoming) is in the actuator <NUM> or the flow regulator <NUM>. This can facilitate the task of corrective action to repair or mitigate the malfunction. Depending on whether the fault is caused by the flow regulator, or by the actuator, the appropriate specialist for the respective unit can repair, replace, or perform other maintenance on the appropriate unit. Diagnosis of a forthcoming malfunction can permit timely inspection and maintenance to prevent the malfunction actually occurring.

The diagnosis may be performed by the actuator controller <NUM>, and/or by the HVAC system controller <NUM> and/or by the remote processor <NUM>.

Diagnosis is performed based on a data model <NUM> representing the device <NUM> and/or device performance. The data model <NUM> may best be understood by referring firstly to a performance curve (<FIG>) representing variation of a characteristic during a cycle to open and close the flow regulator <NUM>. The performance curve may be a load curve, such as a force curve or a torque curve. In the illustration, the performance curve is a torque curve <NUM>, although it is to be understood that references herein to torque are to be understood as applying equally to load and/or force characteristics. Torque may be measured or calculated, or it may be assumed to be proportional to the current flowing through the motor <NUM>. However, other performance curves (e.g. speed, voltage, power, etc) may be used additionally or alternatively, as desired. Also, although the performance curve is representative of operation in a fire damper, the same principles may be used for other types of flow regulator. <FIG> highlights certain characteristics derivable from the performance curve of <FIG>. At least one, preferably some, more preferably a majority, and optionally all, of these characteristics may be useful for the data model <NUM>.

Referring to <FIG>, a technique of the present disclosure is to divide the performance (e.g. torque) curve <NUM> into certain operating windows or zones. Each window represents a phase of operation in which associated parameters can track how the actuator <NUM> and the flow regulator <NUM> are behaving, and can reveal actual or forthcoming faults.

A first window (or "hysteresis" window) <NUM> is when the motor <NUM> starts turning, from a <NUM>° rotational positon. Mechanical backlash or hysteresis in the transmission <NUM> may result in the motor rotor turning up to about <NUM>° without significant movement of the output member <NUM>. Referring to <FIG>, during this window, the torque is relatively low, and may be referred to as the "minimum torque" that is generated by the motor <NUM> during the cycle. The torque curve is influenced primarily by the condition of the actuator <NUM>, ie. by the motor <NUM> and the transmission <NUM>. This window may be represented by one or more of: angular position information of the first window (e.g. one or more of: start position, end position, angular width); and/or torque information defining the torque during the window (e.g. max torque and/or mean torque).

Referring to <FIG> and <FIG>, during a second window ("seal opening" window) <NUM>, the output member <NUM> begins to move and cause the flow regulator <NUM> to begin to open. A seal of the flow regulator <NUM>, creates additional friction during this opening movement, and the torque rises to a local peak <NUM> before dropping back down to a modest level once the seal has opened. One example of such a seal is a lip-seal that has to be forced to flip-over on itself when moving away from the closed condition, resulting in a pronounced peak <NUM>. During this second window, the rotor may turn from about the <NUM>° position to about the <NUM>° positon. The local peak <NUM> results from the action of the seal, and provides an indication of seal condition. For example, <FIG> illustrates an effect of the seal weakening or failing to operate, which may reduce the height of the local peak <NUM>, and shift the angular position of the peak <NUM>. The second window may be represented by one or more of: angular position information of the second window (e.g. one or more of: start position, end position, angular width); and/or information about the nature of the peak (e.g. peak height, angular position of the local maximum within the second window, a mathematical integration of the peak curve, which provides an indication of the area under the peak).

During a third window ("progressive" window) <NUM>, the torque variation remains generally uniform as the motor <NUM> drives the flow regulator progressively towards fully open. In this example, where the actuator includes a spring ("return spring") <NUM> to return the flow regulator to a closed position when power is cut-off, the torque increases linearly modestly as the motor works to compress/extend the return spring <NUM>. The motor rotor turns from about the <NUM>° position to an about <NUM>° position. The third window <NUM> corresponds to the main movement range of the actuator <NUM> and the flow regulator <NUM>. The torque generally rises progressively modestly throughout the window, and any scattering of the torque (e.g. standard deviation), which may be a sign of bearing condition, is most evident in this window. The third window may be represented by one or more of: angular position information of the third window (e.g. one or more of start position, end position, angular width); and/or scattering information (e.g. standard deviation about mean); and/or curve shape information (e.g. max torque value and/or corresponding angular position). Scattering may be evaluated by sampling, for example, about <NUM> data points within the window, and calculating a standard deviation. The standard deviation may be a single value for the window <NUM> as a whole, or for a representative segment 58a of the window <NUM>, or the window <NUM> may be sub-divided into multiple segments, and a standard deviation calculated for each segment. As can be seen in <FIG>, the minimum torque is expected at the start of the window, and the max torque is expected at the end of the window. <FIG> illustrate how a faulty flow regulator <NUM> may influence the torque in the second window. <FIG> illustrates a worn valve bearing unable to properly support the forces applied by the actuator <NUM>. The seal peak <NUM> may be displaced, and the torque curve in the third window is non-linear. <FIG> illustrates a worn valve requiring increased torque <NUM> towards the end of travel in the third window, also resulting in a non-linear torque characteristic.

Referring to <FIG>, the actual torque at the end of the third window may also be registered, whether or not this is the absolute maximum. A difference between the initial torque at the start of the first window <NUM>, and the final torque at the end of the third window <NUM>, is also indicative of the amount of energy stored in the return spring <NUM>, and hence of the condition of the spring <NUM>. This value may be referred to as a "rise feather".

Thereafter, during a fourth window ("open stop" window) <NUM>, the flow regulator <NUM> reaches the fully open position, and comes to a hard stop. The torque increases abruptly almost with a step change impulse characteristic as the motor <NUM> stalls. This phase of operation may correspond to the rotor turning from about the <NUM>° position to about <NUM>°. The abruptness of the stop may also indicate the condition of the flow regulator <NUM> and the coupling <NUM> to the actuator. In case of the actuatable element <NUM> being obstructed before full opening, or in case of the coupling <NUM> becoming worn or weak, movement tends to slow more progressively before coming to a complete stop. For example, the coupling <NUM> may deform slightly under the stop load. The torque curve will then have a less abrupt slope, especially at the start of the fourth window <NUM>, as illustrated for example in <FIG> at <NUM>. The fourth window may be represented by one or more of: angular position information of the fourth window (e.g. one or more of start position, end position, angular width); and/or slope information of the torque curve (e.g. a mathematical derivative and/or differential value indicative of gradient).

The difference in angular position from the start of the first window <NUM> to the end of the fourth window <NUM>, also provides a total travel indication of the actuator <NUM> moving from closed to open.

The total time duration from the start of the first window <NUM> to the end of the fourth window <NUM>, provides additional significant information about how quickly the control device <NUM> operates.

The torque curve is also illustrated to include a fifth window ("return" window) <NUM> corresponding to the spring <NUM> returning the driven member <NUM> and the flow actuator <NUM> to the fully closed position when the power is cut-off from the motor <NUM>. During the fifth window <NUM>, the torque curve becomes negative as the spring drives movement of the motor <NUM>, inducing a generated current and voltage in the motor. The time duration to complete the self-return provides an indication of the condition of the spring <NUM> and/or a degree of friction in the actuator <NUM> and the flow regulator <NUM>. The voltage or current induced in the motor <NUM> during the return can also provide an indication of the degree of uniformity of the return speed. The fifth window may be represented by one or more of: time information representing the self-return time; voltage and/or current information representing the return path characteristics.

<FIG> also indicates a maximum permissible torque threshold <NUM> set for the control device <NUM>. The threshold <NUM> represents a safety limit that ought not to be exceeded in normal use of the control device <NUM>, notwithstanding the momentary impulse upon the flow regulator <NUM> reaching maximum open, which triggers the controller <NUM> to stop the actuator <NUM> at that point. For example, <FIG> illustrates a faulty actuator <NUM> that, due to increased friction or bearing wear over time, requires greater torque generation to drive the flow regulator, ultimately (at <NUM>) exceeding the maximum threshold <NUM> after, for example, around one hundred thousand operating cycles.

<FIG> also shows variation in the torque curve <NUM> depending on when the torque curve <NUM> is taken. A preferred feature of the present disclosure is that performance information is registered at different production and installation stages of the control device <NUM>. The data model <NUM> may be based on, and/or comprise, performance information registered at these different stages.

For example, a first torque curve 50a is shown for the actuator <NUM> measured before it is mated with, or assembled to, the flow regulator <NUM>. This can provide information associated with the actuator <NUM> per se independent of the influence of the flow regulator <NUM>. It can be seen in <FIG> that the first curve 50a is absent the local peak <NUM>, and information registered from the first curve 50a provides a view into pure actuator behaviour even outside the hysteresis window <NUM>.

A second torque curve 50b is shown for the actuator after manufacture and assembly with the flow regulator <NUM>. It can be seen in <FIG> that the second curve 50b includes a relatively pronounced local peak <NUM>, in contrast to the first curve 50a. Information registered from the second curve 50b provides a view into the performance of the actuator <NUM> and flow regulator <NUM> together, when new.

A third torque curve 50c is shown for the device <NUM> after it is installed in an HVAC system, and after a certain number of operating cycles to allow the parts to run-in. It can be seen in <FIG> that this third curve 50c is generally lower than the second curve 50b when new. Running-in of the parts reduces friction in the actuator <NUM> and flow regulator <NUM>. Also lubrication grease within the transmission <NUM> may be relatively viscous or gummy when new. Running-in reduces the viscosity of the grease, also contributing to reduced friction. <FIG> also illustrates at <NUM> the reduction in torque with increasing operating cycle count, as the actuator <NUM> runs-in.

Referring to <FIG> and <FIG>, the information discussed above derived from the performance curve(s) is/are referred to as KPI (key performance indicator) <NUM>. <FIG> is a schematic map showing processing steps or modules for processing KPI for analysis. <FIG> is a table indicating how different KPI parameters can be interpreted to distinguish between malfunctions of the actuator <NUM> (left column) and flow regulator <NUM> (right column).

Referring to <FIG>, the KPI <NUM> is obtained at three different stages <NUM> of manufacture and installation discussed above, namely (i) for the actuator <NUM> alone prior to assembly to the flow regulator <NUM>; (ii) for the actuator <NUM> and flow regulator <NUM> together after assembly; and (iii) for the control device <NUM> once installed in an HVAC system, and optionally after a period of running-in. Additionally or alternatively, KPI may be obtained for the control device during, or immediately after, or shortly after installation in an HVAC system, so that any changes or effects of the installation on the control device <NUM> may be taken into account (e.g. even before running in) compared to the control device <NUM> as new. Optionally, characteristics may be measured for the control device <NUM> immediately before installation. This can enable effects such as distortion of the fluid flow path by the duct to be accounted for.

The KPI <NUM> forms at least part of the data model <NUM>. In order to diagnose current performance, either during a dedicated test run or during normal operation of the HVAC system, current values of KPI parameters are calculated from the signals supplied by the sensors <NUM> (and optionally <NUM>) during a partial or complete open-close cycle commanded by the controller <NUM>. Also, KPI from one or more previous runs are used in the form of historical data, optionally a weighted average, to enable tracking of changes and/or trends in the KPI. The previous KPI and/or weighted average may be stored as part of an evolving data model, or as separate information.

Referring to <FIG>, the KPI <NUM> in the data model may comprise one or more (optionally at least some and/or at least a majority, and/or all) of:.

Optionally, the KPI may further include seventh torque information (not shown) associated with a calculated gradient of the slope at the start of the fourth window <NUM> (e.g. associated with indications of how the flow regulator <NUM> stops at its open position).

Referring to <FIG>, at <NUM>, the current KPI is compared with certain thresholds in the data model to see whether certain safety limits are being exceeded, namely:.

At <NUM> (<FIG>), the current KPI are further analysed to determine trends in the KPI compared to historical KPI, and optionally compared to predicted KPI (discussed later). For example, the analysis may concern one or more or all of:.

The above analysis and diagnosis may be implemented by suitable automated techniques, for example, by one or more of machine learning, a neural network, a fuzzy logic network, an artificial intelligence system. Parameters may be evaluated in combination to refine a distinction between whether a malfunction (actual or forthcoming) is present in the actuator <NUM> or in the flow regulator <NUM>.

<FIG> illustrates values and trends of the KPI parameters <NUM> that, in isolation and/or in combination, characterise performance of the flow control device <NUM>, and that can reveal or diagnose actual and forthcoming malfunctions. In <FIG>, the left column identifies values/trends associated with malfunction of the actuator <NUM>, and the right column identifies values/trends associated with malfunction of the flow regulator <NUM>. Upward arrows indicate values increasing. Horizontal arrows indicate that changes in value are not expected and/or are not relevant. Multi-direction arrows indicate that any change in value may be relevant. Although a single set of trend values is illustrated, multiple trends associated with a variety of malfunctions in the actuator and/or the flow regulator may optionally be provided or learned by machine learning. Different trends may optionally refer to differing sets or sub-sets of the KPI parameters <NUM>.

<FIG> illustrate how KPI parameters <NUM> may be interpreted in actual testing to diagnose malfunctions.

In a first example, the manner in which parameter values vary with usage (represented by cycle count) is depicted in <FIG> and <FIG>. The cycle count is indicated on the abscissa. Each parameter line is denoted by the same reference numeral used in <FIG>. In particular, <FIG> shows the variation in the maximum torque information <NUM> from the third window <NUM>; variation in standard deviation <NUM> represented by broken lines neighbouring line <NUM>; variation in return time <NUM> from the fifth window <NUM>; and variation in the hysteresis torque <NUM> from the first window <NUM>. <FIG> shows the variation in the range information <NUM>; variation in the spring torque (rise feather) <NUM>; and variation in the integral <NUM> of the seal peak <NUM>.

Referring to <FIG>, a first indication of a fault is apparent from the abnormal excursion <NUM> of the return time <NUM> at a cycle count of about <NUM>. Additional excursions of the return time <NUM> and of the maximum torque <NUM> are also detectable at three occurrences <NUM>. In general, the maximum torque <NUM>, the return time <NUM>, the hysteresis torque <NUM> (indicated by arrow <NUM>), the spring torque <NUM> and the integral of the seal peak <NUM> (both indicated by arrows <NUM>) all show a trend of increasing. Referring to <FIG>, these increases correspond generally to the trends indicated in the left column of the parameter table, indicative of a malfunction of the actuator <NUM>. The forthcoming malfunction is apparent from the first indication at about <NUM> cycles, although the actuator <NUM> may actually manifest malfunctions after about <NUM> cycles.

In fact the parameters represented in <FIG> and <FIG> represent actual test values from a flow control device <NUM> with a faulty actuator having a worn bearing. Also notable in <FIG> is that the standard deviation <NUM> was generally stable (indicated by arrow <NUM>), but this does not compromise the other trends. Also notable in <FIG> is an abnormal excursion (<NUM>) of the travel range <NUM> occurring at about <NUM> cycles, which also would be an anomaly for triggering a warning.

In a second example, the manner in which parameter values vary with usage (represented by cycle count) is depicted in <FIG>. The cycle count is indicated on the abscissa. Each parameter line is denoted by the same reference numeral used in <FIG>. In particular, <FIG> shows the variation in return time <NUM> from the fifth window <NUM>; variation in the magnitude <NUM> of the seal peak <NUM> from the second window <NUM>; variation in the maximum torque information <NUM> from the third window <NUM>; variation in standard deviation <NUM> represented by broken lines neighbouring line <NUM>; and variation in the hysteresis torque <NUM> from the first window <NUM>. <FIG> shows the variation in the integral <NUM> of the seal peak <NUM>; variation in the range information <NUM>; and variation in the spring torque (rise feather) <NUM>.

Referring to <FIG>, an indication of a fault is apparent from the abnormal excursion <NUM> of the seal torque <NUM> and the abnormal excursion <NUM> of the position range <NUM> at a cycle count of about <NUM>. The calculated integral <NUM> also shows a decrease from about <NUM> cycles. Other parameters (e.g. max torque <NUM>, standard deviation <NUM>, and spring torque <NUM>) generally remain flat. Referring to <FIG>, such a combination corresponds generally to the trends indicated in the right column of the parameter table, indicative of a malfunction of the flow regulator <NUM>. The forthcoming malfunction is apparent even earlier, from about <NUM> cycles, is very apparent at <NUM> cycles, and continues until the flow regulator stops working at about <NUM> cycles.

In fact, the parameters represented in <FIG> represent actual test values from a flow control device <NUM> with a faulty flow regulator <NUM> that was tested until breakage. Notable in <FIG> (as indicated by arrow <NUM>) is that the maximum torque and the standard deviation <NUM> were generally stable. Also notable in <FIG> is that the return time <NUM> also remained generally stable until the flow actuator broke and could not travel the full return distance.

Referring to <FIG>, an enhancement of the above techniques may take into account temporal influences on the KPI parameters <NUM>. For example, temporal influences may include one or more of:.

Referring to <FIG> and <FIG>, a further enhancement of the analysis techniques may to employ an adaptive technique. The adaptive technique may comprise one or both of:.

Such an enhanced analysis technique can be responsive to, or driven by, data from other flow control devices <NUM>. The predictive data model module <NUM> enables a data module to be generated representing how the flow control device <NUM> is expected to perform, based on information from outside the flow control device <NUM> itself. Similarly, the diagnosis module <NUM> enables fault diagnosis based on fault information derived from other flow control devices <NUM>.

Referring to <FIG>, the predictive analysis may be performed in the processing system <NUM> that is able to receive signals from multiple flow control devices <NUM>, optionally in the same HVAC system <NUM>, and/or optionally in plural different HVAC systems. The controller <NUM> may be operable to perform a more simple analysis on-board the flow control device <NUM>. The characteristics for the on-board analysis may be updated and/or adapted according to information available to the processing system <NUM>, for example, using one of the communication channels or the portable apparatus <NUM>.

Also, <FIG> shows the flow control device <NUM> comprising an interface module <NUM> communicating with or forming part of the controller <NUM>. The interface module <NUM> comprises a control interface <NUM> for interfacing with the HVAC system controller <NUM>, and/or a data model interface <NUM> for receiving the data model information <NUM> and storing the data model in the flow control device <NUM>, and/or a diagnostic interface <NUM> for receiving and sending diagnostic information. The diagnostic information my include the calculated KPI parameters <NUM>, and/or signals from the sensors <NUM> and <NUM> for remote processing, and/or the results of diagnostic tests for identifying actual malfunctions and/or forthcoming malfunctions, and optionally for discriminating between malfunctions (actual or forthcoming) in the actuator <NUM> or the flow regulator <NUM>.

<FIG> and <FIG> illustrate how the parameters of the flow control device <NUM> are set-up and used depending on the manner of production and installation of the flow control device <NUM>. The process is divided into sections, namely: a first ("production") stage <NUM> representing production of a new actuator <NUM>; an optional second ("damper assembly") stage <NUM> at which the new actuator <NUM> is assembled to a new flow regulator <NUM>, to complete manufacture of a new flow control device <NUM>; a third ("installation") stage <NUM> at which the components are physically installed into an HVAC system; a fourth ("integration and commissioning") stage <NUM> at which the components are made operational within the HVAC system; a fifth ("testing") stage <NUM> at which the function of the flow control device <NUM> is tested and actual or forthcoming malfunctions are diagnosed. The process is described for a flow regulator <NUM> in the form of a fire damper, as an example of a flow control device <NUM> required to meet high safety standards. However, the same process may be applied for other types of flow regulator <NUM>. The terms "flow regulator" and "damper" are substitutable one for the other, and are referred to interchangeably.

During the first production stage <NUM>, step <NUM> represents manufacture of the new actuator <NUM>, followed by testing of the actuator <NUM> at step <NUM>. During step <NUM>, characteristic parameters of the actuator <NUM> per se may be recorded for the data model, providing a view on operation of the actuator <NUM> alone, even outside the hysteresis window. The information may be recorded by establishing a birth-certificate and/or other unique identifier for the particular actuator <NUM>. The information may be stored as part of the birth certificate, and/or in a separate database accessible by means of the birth certificate. For example, the information may be stored in the remote processing system <NUM>. Additionally or alternatively, information may be inputted via the model interface <NUM> and stored within the actuator controller <NUM>.

Following production of the actuator <NUM>, the process may take one of three possible paths <NUM>, <NUM> or <NUM>, depending on how the actuator <NUM> is to be used.

A first path <NUM> represents the production of a new flow control device <NUM> using the actuator <NUM> at the second assembly stage <NUM>. The second assembly stage <NUM> may be carried out by the same manufacturer as the first stage <NUM>, or by a different manufacturer (for example, in an OEM production process). Step <NUM> represents the actuator <NUM> being assembled to the new flow regulator <NUM> in the form of a fire damper, to form the new flow control device <NUM>. At step <NUM>, the assembled actuator <NUM> and damper (flow regulator <NUM>) are tested together. During step <NUM>, characteristic parameters of the actuator <NUM> and damper together may be recorded for the data model, providing a view on operation of the device <NUM> as new. The information may be recorded with and/or associated with the birth-certificate. The information may optionally be stored in the remote data processing system <NUM> and/or in the actuator controller <NUM>, in a similar manner to that described above.

Still referring to the first path <NUM>, the flow control device <NUM> is physically installed in an HVAC system <NUM> at the third installation stage <NUM>. Step <NUM> represents the step of installing the flow control device <NUM> as a combined unit.

At the fourth installation/commissioning stage <NUM>, the necessary testing and integration of the flow control device <NUM> are carried out. Step <NUM> represents a data processing step of allocating the flow control device identity within the HVAC system. Step <NUM> represents testing the flow control device <NUM> after installation. In addition to documenting correct operation, step <NUM> may also include recording, for the data model, characteristic parameters for the device <NUM> in its installed state. The information may be recorded with and/or associated with the birth-certificate. The information may optionally be stored in the remote data processing system <NUM> and/or in the actuator controller <NUM>, in a similar manner to that described above.

Step <NUM> is an optional step if the HVAC system is newly installed in a building. A complete system test may be carried out to verify and document correct operation.

The second path <NUM> is similar to the first path <NUM>, except that the actuator <NUM> and the damper (flow controller <NUM>) are installed as separate new devices in the HVAC system rather than being "manufactured" as a unit. The second path <NUM> thus skips the second assembly stage <NUM>. Instead, at the third installation stage <NUM>, the damper is installed at step <NUM> followed by the actuator <NUM> at step <NUM>.

Still referring to the second path <NUM>, during the fourth installation/commissioning stage <NUM>, testing and integration of the flow control device <NUM> is carried out in a similar manner to that already described. Step <NUM> (similar to step <NUM>) represents a data processing step of allocating the flow control device identity within the HVAC system. Step <NUM> is an additional step of testing and documenting that the actuator <NUM> and damper function correctly together. Step <NUM> (similar to step <NUM>) represents testing the flow control device <NUM> as part of the HVAC system. In addition to documenting correct operation, step <NUM> and/or <NUM> may also include recording, for the data model, characteristic parameters for the device <NUM> in its installed state. The information may be recorded with and/or associated with the birth-certificate. The information may optionally be stored in the remote data processing system <NUM> and/or in the actuator controller <NUM>, in a similar manner to that described above.

The third path <NUM> is somewhat similar to the second path <NUM>, except that the new actuator <NUM> is retrofitted to a damper (flow regulator <NUM>) that is already installed in the HVAC system, e.g. to replace a previous defective actuator. The third path <NUM> thus passes directly to the third installation stage <NUM> in which the actuator <NUM> is installed with the existing damper at step <NUM> (similar to step <NUM>). The third path <NUM> continues to the fourth integration/commissioning stage <NUM>, at which processing is similar to the second path <NUM>. Step <NUM> (similar to steps <NUM> and <NUM>) represents a data processing step of allocating the flow control device identity within the HVAC system. Step <NUM> (similar to step <NUM>) represents testing and documenting that the actuator <NUM> functions correctly with the damper. Step <NUM> (similar to steps <NUM> and <NUM>) represents testing the flow control device <NUM> as part of the HVAC system. In addition to documenting correct operation, step <NUM> and/or <NUM> may also include recording, for the data model, characteristic parameters for the device <NUM> in its installed state. The information may be recorded with and/or associated with the birth-certificate. The information may optionally be stored in the remote data processing system <NUM> and/or in the actuator controller <NUM>, in a similar manner to that described above.

Testing stage <NUM> represents later testing of the HVAC system <NUM>, optionally particularly the flow control device <NUM>. Testing may be carried out by regular checks, for example, to comply with local laws. Additionally or alternatively, testing may be carried out during regular maintenance. Additionally or alternatively, the control device <NUM> may monitor its operating performance as part of normal operation when the actuator <NUM> is commanded to move, and/or by the HVAC system controller <NUM> and/or the actuator controller <NUM> commanding periodic self-checks. Step <NUM> represents the actuator controller <NUM> generating commands to cause the actuator <NUM> to drive movement of the damper (flow regulator <NUM>). Step <NUM> represents the controller <NUM> receiving signals from the sensors <NUM> (and optionally <NUM>). Step <NUM> represents diagnosis of the flow control device <NUM> based on the sensor signals, to determine the presence (actual of forthcoming) of a malfunction, and to distinguish whether the malfunction is in the actuator <NUM> or the damper (flow regulator <NUM>). Step <NUM> represents replacement and/or maintenance of the actuator <NUM> in the event of detecting actuator malfunction. Replacement would involve retrofitting a new actuator <NUM> as above.

The fourth integration/commissioning stage <NUM> and/or the fifth testing stage <NUM> may optionally be carried out with the assistance of the portable device <NUM>. The portable device <NUM> may be a dedicated apparatus, or it may be a mobile computing device running application software. The portable device <NUM> may communicate with the actuator controller <NUM> by any local or wide-are communication protocol. An example of a local protocol may, for example, be NFC (near field communication) with which the interface <NUM> and the mobile device <NUM> may both be equipped.

The portable device <NUM> may be configured to guide an operator through the process steps of the fourth stage <NUM> and/or the fifth stage <NUM>, and to display results generated by the control device <NUM>.

The portable device <NUM> may also be used to access reference and performance curves stored during the production stages of the actuator <NUM> and/or the damper (flow regulator <NUM>). Additionally or alternatively, the portable device <NUM> may be used to access pending and/or archived error and/or warning messages. Additionally or alternatively, the portable device <NUM> may be used to access documentation referencing the control device <NUM> or one of its parts (e.g. actuator <NUM> and/or damper) such as specifications, datasheets or installation instructions.

The portable device <NUM> may also be used to access documentation referring to the installation site, such as a building plan. Location or position determination of portable unit <NUM> may be used to enhance the information provided (e.g. by indicating the location on the building plan).

Portable device <NUM> may also be used to control access to the control device <NUM>.

Claim 1:
Method of controlling an HVAC system (<NUM>) comprising:
- at least one flow regulator (<NUM>) comprising an actuatable element (<NUM>) for regulating fluid flow in a fluid path;
- an electro-mechanical actuator (<NUM>) associated with the flow regulator, to actuate the flow regulator, wherein the actuator comprises an electric motor (<NUM>) driving a movable output member (<NUM>);
- one or more sensors (<NUM>) associated with the actuator, wherein the sensors are chosen from the group consisting of load sensors, force sensors, torque sensors, current sensors, voltage sensors, power sensors, speed sensors and position sensors;
- a controller (<NUM>) operatively connected with the actuator and the sensor(s);
- optionally, a mechanism, optionally a lever mechanism, operatively connecting the output member with the flow regulator;
wherein the method comprises the steps of:
i. actuating (<NUM>) the flow regulator;
ii. receiving (<NUM>) signals from the one or more sensors;
iii. determining an actual or forthcoming malfunction, based on the signals received in step ii.;
iv. indicating said actual or forthcoming malfunction to an operator of said HVAC system;
wherein it is distinguished in step iv. between an actual or forthcoming malfunction of:
- the actuator (<NUM>); and
- the flow regulator (<NUM>);
characterized in that the step of determining an actual or forthcoming malfunction comprises diagnosing a forthcoming malfunction.