DE20022539U1 - Regulator for electrically operated control devices - Google Patents

Description

-1 - KHL&SCHAAFHAUSEN

patent attorneys

Controller for electrically operated actuators

The invention relates to a controller for electrically operated actuating devices with charge storage.

Radiator controllers, e.g. in the form of thermostatic valves, are used to regulate the room temperature. In addition to these controllers without auxiliary power and with manual setpoint adjustment, control devices with auxiliary power are increasingly being used, e.g. electric motor-operated actuators. The power supply can be via a supply line or batteries. This makes it possible to specify certain temperature profiles depending on the time, which the temperature controller automatically follows. This means that the radiator in question can be lowered at night without the user having to make manual settings on the controller. Modern temperature controllers also have an integrated window open detection function, which causes the valve to close automatically when window ventilation is detected in order to reduce ventilation heat losses.

So-called PI controls with a proportional and an integral control component are often used as controllers. These controls calculate a target setting for opening or closing the radiator valve from a detected difference between the actual and setpoint temperature. The energy supply is provided by batteries, especially for small devices without their own power connection, such as individual room temperature controllers on radiators. However, it has been found that with such electrically operated individual temperature controllers, the service life of the batteries is often significantly lower than that required for the device due to the relatively high power consumption.

10 August 2001 T15 G8

- 2 - KEIL&SCHAAFHAUSEN

patent attorneys

typical battery life, so that frequent battery changes are necessary or automatic control no longer takes place.

The object of the invention is therefore to extend the service life of the charge storage devices.

The object is essentially achieved in a controller for electrically operated actuating devices with an actuator, a control system for controlling the actuator and a charge storage device in that the controller has a charge counter for monitoring the amount of charge consumed, a storage unit for storing the value of the available amount of charge, the value of the amount of charge consumed and/or an evaluation factor and a computing unit for determining the available amount of charge and, if applicable, the evaluation factor.

In a particularly advantageous embodiment, the storage unit and the computing unit are designed as a logic capacitor with a continuous counter for adding the amount of charge available per time interval and for subtracting the amount of charge actually used. Any unused available charge is added up and can be used up later if the actuating activity increases.

On the basis of the charging capacity of the charge storage device, the actuating device is assigned a charge quantity available per unit of time, e.g. day, whereby the charge consumption of the actuating device is monitored and the actuating movements of the actuating device are restricted if the charge quantity actually consumed exceeds the charge quantity available for the unit of time.

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- 3 - KEIL&SCHAAFHAUSEN

PATENT ATTORNEYS

By limiting the positioning movements of the control device, the control tends to behave more slowly and the time constant of the control is increased, so that the reaching of the setpoint is delayed. Since most controls adapt the actual value to a setpoint asymptotically, i.e. they first quickly bring the actual value close to the setpoint and then adjust it slowly (asymptotically), essentially only the slow adjustment is delayed. This delay is hardly noticeable by the user in a temperature control and does not lead to any significant additional heat losses. Due to the reduction in charge consumption by limiting the positioning movements, a significant extension of the service life of the charge storage can still be achieved. The amount of charge available per unit of time is determined by the total capacity of the charge storage and the desired

Total service life. In addition to extending the service life of the charge storage devices, this also means that their total service life can be planned relatively precisely in advance without having to accept significant functional limitations of the control system.

To monitor the charge consumption, a so-called logic capacitor can be used, in which the amount of charge intended for average consumption is added to a continuous counter once per unit of time, e.g. once per day, and the amount of charge actually consumed is subtracted from the counter. If the amount of charge actually consumed is less than the amount of charge available, the counter reading will increase. If, on the other hand, the amount of charge actually consumed is greater than the amount of charge available, the counter reading will decrease. This counter adds up the amount of charge saved in a period with low control activity, so that it can be used up in times with greater control activity. For example, when controlling the temperature in summer, only a few

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- 4 - KEIL&SCHAAFHAUSEN

patent attorneys

Adjustment movements are carried out, while in winter there is an increased need for control.

In another embodiment, in order to monitor the charge consumption, the amount of charge actually consumed in a unit of time is subtracted from the amount of charge intended for consumption per unit of time. If a threshold value is undershot, e.g. if the difference is negative, the actuating movements of the actuating device are then restricted in order to reduce the charge consumption.

Otherwise, all adjustment movements are carried out in order to obtain an optimal control process.

Limiting the actuating movements to reduce charge consumption can be achieved particularly effectively by limiting the maximum actuating travel of the actuating device. This limits the running time of the actuator during the actuating movement, which has a particular effect when the valves are opened and closed. In an individual room temperature controller, a fully open valve does not cause a significant increase in the mass flow compared to a valve that is only half open, so that the saving in charge consumption can be achieved without significantly affecting the heating behavior.

The limitation of the positioning movements can also be achieved by reducing the positioning range that can be used by the control and/or increasing the minimum positioning range from which a positioning movement is carried out. The relative reduction of the target positioning range means that the actual value is brought closer to the target value more slowly. This prevents over-regulation, which in turn would cause counter-regulation with new positioning movements. If the limit value for triggering a positioning movement is increased, the control tolerates larger deviations from the

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- 5 - KEIL& SCHAAFHAUSEN

PATENT ATTORNEYS

setpoint before it becomes active. This prevents frequent readjustment with correspondingly small adjustment movements. The charge saving is particularly large here, since the power consumption at the beginning of the adjustment movement, e.g. when the servomotor starts up, is relatively high.
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In addition, the actuating movement can be limited by adjusting the integral action time of the control, the control gain and/or similar parameters. For example, the dynamic behavior of the control is changed by changing the proportional and/or integral control parameters of a PI control.

The parameters for controlling the actuating movement, such as maximum actuating travel, target actuating travel, minimum actuating travel, reset time, control gain, etc., are preferably weighted with an evaluation factor derived from the available charge quantity. In this way, the control behavior is continuously adapted to the charge state of the charge storage and different gradations in the restriction of the actuating movements are made possible. For example, when ventilating a window, the valve of the individual room temperature controller can close completely if the evaluation factor indicates a full charge storage. If the charge state is reduced, the valve will no longer close completely, but will move to an intermediate position between the current position and the closing point. If, on the other hand, a critical charge state is undershot, the current valve position is frozen and the control no longer reacts at all.

The evaluation factor, which is preferably between 0 and 1, is formed in the logic capacitor using a calculation rule from the counter reading. In this way, the evaluation factor can be optimally adapted to the control algorithms. The smaller the evaluation factor, the slower the control response.

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10 August 2001 T15 G 8

- 6 - KHL& SCHAAFHAUSEN

PATENT ATTORNEYS

Further developments, advantages and possible applications of the invention also emerge from the following description of an embodiment and the drawing. All described and/or illustrated features form the subject matter of the invention, either individually or in any combination, regardless of their summary in the claims or their reference back to them.

Show it:

Fig. 1 is a schematic flow diagram for the control of a

Adjustment movement and

Fig. 2 shows schematically the structure of a controller according to the invention.

The control is described below using an example of an electric motor-operated radiator controller that is powered by batteries or accumulators. However, the control is not limited to such controllers, but is equally suitable for all electrically operated control devices with charge storage.

With a radiator controller, a temperature measurement is carried out at regular intervals, which can be influenced by the controller if necessary, to determine the actual value of the room temperature. The control process shown in Fig. 1 is then called up.

After the call, the first question is asked whether this is the first call within a certain time unit. When the call is made for the first time, the amount of charge intended for consumption in the time unit is added to a continuous counter in a logical capacitor. This is determined from the total battery capacity of the batteries arranged in the radiator controller.

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10 August 2001 T 15 G 8

- 7 - KEIL&SCHAAFHAUSEN

patent attorneys

and the desired total service life of the charge storage. The continuous counter then shows the amount of charge that can be used in the specified time unit. For radiator controllers, a day has proven to be a useful time unit.
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A query is then made as to whether there is a difference between the measured actual temperature value and the specified temperature setpoint that needs to be adjusted. If there is no difference between the actual value and the setpoint, the control process is terminated after the amount of charge consumed since the last energy comparison has been recorded and is called up again after the next temperature measurement.

Otherwise, the control process is initiated and a weighting factor is first calculated in the logical capacitor, which provides information about the energy available. To do this, the counter reading of the continuous counter is queried. As long as the counter reading is positive, i.e. the amount of charge actually consumed is less than the amount of charge available, the weighting factor is set to 1, for example. If the counter reading is negative, the weighting factor is reduced according to a predetermined calculation rule until it reaches a minimum value of 0. A weighting factor <1 indicates that more energy has already been consumed up to now than is planned to achieve the desired total service life of the battery. It is of course possible to set the weighting factor differently if the equations for the control parameters are designed accordingly. The weighting factor can also be set between 0 and 2.0 and 50 or even -1 and 1.

Based on the evaluation factor determined by the logic capacitor, the parameters for the valve position change are then determined. For this purpose, the maximum valve opening, the

10. August 2001 T15 G8

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- 8 - KHL& SCHAAFHAUSEN

PATENT ATTORNEYS

The target travel, the minimum travel, the reset time and/or the control gain are calculated according to functions that include the weighting factor. This means that the behavior of the controller tends to be more sluggish the smaller the weighting factor is.
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Then, based on preset specifications, it is checked whether the conditions for readjustment are met. These conditions can in turn depend on the evaluation factor, i.e. the charge level of the batteries, or be independent of it. If the conditions are met, the actuating movement is carried out by the electrically driven actuator.

Finally, before the control process ends, regardless of whether an adjustment movement has taken place or not, the actual amount of charge consumed is subtracted from the counter in the logic capacitor in order to update the energy balance. The actual amount of charge consumed is determined in particular by the motor movements during the adjustment movement, which can be influenced by changes in the control behavior, as well as by PC activities, temperature measurements and possibly radio activities to a central apartment control center, which cannot be influenced.

As shown in Fig. 2, a controller 1 for carrying out the control method described above has an actuator 2 for the actuating movements and a control 3 with a charge storage for controlling the actuator 2. In addition, a storage unit 4 is provided which is connected to the control 3 and which is combined with a computing unit 5 to form a logic capacitor 6. In the logic capacitor 6, the storage unit 4 and the computing unit 5 work together in such a way that the amount of charge intended for average consumption is added to a continuous counter once a day and the actual

10. Auaust2001 T 15 G 8

- 9 - KOLA SCHAAFHAUSEN

PATENT ATTORNEYS

The amount of charge consumed is subtracted from this counter. The counter reading is available as a storage value, as is an evaluation factor calculated from the counter reading. A charge counter 7 is connected to the logic capacitor 6, which measures the amount of charge actually consumed by pC activities, temperature measurements, radio activities and motor movements.

The invention creates the possibility of economical, automatic consumption control, which ensures effective control over a long period of time due to the monitoring of the amount of charge consumed and, if necessary, restriction of the control activities, even in the case of controllers with separate charge storage devices.

Aiinust2001 T 15 G 8

Keil&Schaafhausen

PATENT ATTORNEYS

List of reference symbols:

1 Controller 2 Actuator 3 regulation 4 Storage unit 5 Computing unit 6 logical capacitor 7 Charge counter

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10 August 2001

T15G8

Claims (2)

1. Controller for electrically operated actuating devices with charge storage, with an actuator ( 2 ), a control ( 3 ) for controlling the actuator ( 2 ) and a charge storage, characterized by a charge counter ( 7 ) for monitoring the amount of charge consumed, a storage unit ( 4 ) for storing the value of the available amount of charge, the value of the amount of charge consumed and, if applicable, an evaluation factor, and a computing unit ( 5 ) for determining the amount of charge available for the actuating movements of the actuator ( 2 ) and, if applicable, the evaluation factor. 2. Controller according to claim 1, characterized in that the storage unit ( 4 ) and the computing unit ( 5 ) are designed as a logic capacitor ( 6 ) with a continuous counter for adding the charge available per unit of time and for subtracting the charge actually consumed.