Method for open-loop and closed-loop control of a lighting busway

1. A method for open-loop and closed-loop control of a lighting busway for an interior space, the lighting busway having a primary luminaire and a secondary luminaire, the method comprising:

measuring a brightness at a location of the primary luminaire;

determining a primary ambient light percentage for the primary luminaire by comparing a brightness curve of the primary luminaire without ambient light and the combined brightness measured at the location of the primary luminaire with ambient light and light from the primary luminaire, in each case with respect to a primary manipulated variable of the primary luminaire;

determining a secondary ambient light percentage for the secondary luminaire based on the primary ambient light percentage; and

determining a secondary manipulated variable for the secondary luminaire based on the secondary ambient light percentage and a setpoint value for the secondary luminaire.

2. The method as claimed in claim 1 , wherein the secondary ambient light percentage of the secondary luminaire is determined by multiplying the primary ambient light percentage by a specific factor for the secondary luminaire.

3. The method as claimed in claim 2 , wherein

there are a plurality of secondary luminaires,

each secondary luminaire has a respective specific factor that depends on a position of the secondary luminaire within the interior space, and

the secondary ambient light percentage and the secondary manipulated variable are determined individually for each secondary luminaire.

4. The method as claimed in claim 2 , wherein

the specific factor is determined using a calibration method which takes into account an ambient light gradient from an incidence position of the ambient light into the interior space for the secondary luminaire.

5. The method as claimed in claim 4 , wherein the calibration method comprises:

determining current ambient light values in the absence of artificial light for the primary luminaire and for the secondary luminaire; and

determining the specific factor for the secondary luminaire by dividing the ambient light value for the secondary luminaire by the ambient light value for the primary luminaire.

6. The method as claimed in claim 4 , wherein the calibration method is performed several times at different points in time.

7. The method as claimed in claim 6 , wherein when determining the secondary ambient light percentage, the specific factor used is time-dependent.

8. The method as claimed in claim 2 , wherein

the primary ambient light percentage is standardized to the primary luminaire, and

the specific factor for the secondary luminaire relates to the primary ambient light percentage.

9. The method as claimed in claim 1 , wherein when determining the secondary manipulated variable for the secondary luminaire, a comparison is performed between a setpoint value for brightness at a location of the secondary luminaire and the secondary ambient light percentage.

10. The method as claimed in claim 1 , wherein a primary manipulated variable is determined for the primary luminaire based on the primary ambient light percentage.

11. The method as claimed in claim 10 , wherein the primary manipulated variable is applied in a closed-loop control circuit and the secondary manipulated variable is applied in an open-loop control system.

12. The method as claimed in claim 1 , wherein

the lighting busway includes at least first and second secondary luminaires, and

the setpoint value of the first secondary luminaire differs from the setpoint value of at least one of the second secondary luminaire and the primary luminaire.

13. The method as claimed in claim 1 , wherein

the brightness measured at the location of the primary luminaire includes an artificial light component and a natural, ambient light component,

the primary ambient light percentage is obtained using a brightness curve of the primary luminaire without ambient light,

a primary manipulated variable of the primary luminaire relates to an amount of power supplied to the primary luminaire, and

the primary ambient light percentage is obtained from a comparison of the brightness measured while using the primary manipulated variable and a brightness that would be obtained using the primary manipulated variable, without the ambient light component.

14. The method as claimed in claim 2 , wherein

ambient light is introduced into the interior space from an incidence position, and

the specific factor is determined using a calibration method which takes into account:

an ambient light gradient specifying how the ambient light decreases across the interior space, with increased distance from the incidence position; and

relative positions of the primary and secondary luminaire with respect to the incidence position.

15. The method as claimed in claim 14 , wherein

the ambient light gradient changes with time and depends on a relative position of the sun, and

the secondary ambient light percentage is determined using the ambient light gradient appropriate for a current time of day.

16. The method as claimed in claim 1 , wherein

the lighting busway includes at least first and second secondary luminaires,

the primary luminaire, the first secondary luminaire and the second secondary luminaire have a common setpoint value, and

the common setpoint value is achieved by using a different manipulated variable for each of the first and second secondary luminaires and the primary luminaire.

17. A lighting busway comprising:

a primary luminaire and a secondary luminaire for lighting an interior space; and a brightness regulation device comprising:

a light sensor to measure a brightness at a location of the primary luminaire; and

an electronic device to:

determine a primary ambient light percentage for the primary luminaire by comparing a brightness curve of the primary luminaire without ambient light and the combined brightness measured at the location of the primary luminaire with ambient light and light from the primary luminaire, in each case with respect to a primary manipulated variable of the primary luminaire;

determine a secondary ambient light percentage for the secondary luminaire based on the primary ambient light percentage; and

determine a secondary manipulated variable for the secondary luminaire based on the secondary ambient light percentage and a setpoint value for the secondary luminaire.

18. The lighting busway as claimed in claim 17 , wherein the brightness regulation device is arranged in or on the primary luminaire.