Temperature control of an environment to achieve occupant comfort based on heart rate variability parameters

1. A temperature control system, comprising:

a heating, ventilation and air conditioning (HVAC) system configured to control temperature in an environment;

a sensor configured to generate an electrocardiogram (ECG) signal for an occupant of the environment;

an environmental sensor configured to sense environmental data selected from a group consisting of the environmental temperature, an ambient temperature, air velocity, sun load and humidity; and

a heart rate variability (HRV) controller configured to:

receive the ECG signal;

identify inter-beat intervals based on the ECG signal; and

control the HVAC system based on the inter-beat intervals and the environmental data, wherein the HRV controller is further configured to:

compare the inter-beat intervals to a first threshold and a second threshold, wherein the first threshold is less than the second threshold;

increase heating in the environment when at least one of the inter-beat intervals is less than the first threshold; and

increase cooling in the environment when at least one of the inter-beat intervals is greater than the second threshold.

2. The temperature control system of claim 1 , wherein the HRV controller is further configured to:

adjust at least one of the first threshold and the second threshold in response to a manual setpoint change to the HVAC system; and

use the adjusted value of the at least one of the first threshold and the second threshold to control the HVAC system.

3. The temperature control system of claim 1 , wherein the HRV controller is configured to control the HVAC system further based on variations in the inter-beat intervals.

4. A temperature control system, comprising:

a heating, ventilation and air conditioning (HVAC) system configured to control temperature in an environment;

a sensor configured to generate an electrocardiogram (ECG) signal for an occupant of the environment;

an environmental sensor configured to sense environmental data selected from a group consisting of the environmental temperature, an ambient termerature, air velocity, sun load and humidity; and

a heart rate variability (HRV) controller configured to:

receive the ECG signal;

identify inter-beat intervals based on the ECG signal; and

control the HVAC system based on the inter-beat intervals and the environmental data, wherein the HRV controller is further configured to:

compare a variation in the inter-beat intervals to a predetermined variation threshold;

control the HVAC system using a temperature setpoint when the variation is greater than the predetermined variation threshold; and

control the HVAC system using a correlation between the inter-beat intervals and comfort of the occupant of the environment when the variation is less than the predetermined variation threshold.

5. A temperature control system, comprising:

a heating, ventilation and air conditioning (HVAC) system configured to control temperature in an environment;

a sensor configured to generate an electrocardiogram (ECG) signal for an occupant of the environment;

an environmental sensor configured to sense environmental data selected from a group consisting of the environmental temperature, an ambient temperature, air velocity, sun load and humidity; and

a heart rate variability (HRV) controller configured to:

receive the ECG signal;

identify inter-beat intervals based on the ECG signal; and

control the HVAC system based on the inter-beat intervals and the environmental data, wherein the HRV controller is further configured to:

generate N HRV parameters based on the inter-beat intervals, where N is an integer greater than one; and

use a comfort classification model defined in a N-dimensional HRV parameter space.

6. The temperature control system of claim 5 , wherein the HRV controller is further configured to determine the comfort of the occupant of the environment based on the N HRV parameters and the comfort classification model.

7. The temperature control system of claim 5 , wherein the comfort classification model defines at least one comfort region in the N-dimensional HRV parameter space and at least one discomfort region in the N-dimensional HRV parameter space.

8. The temperature control system of claim 5 , wherein the HRV controller is further configured to train the comfort classification model based on manual setpoint changes to the HVAC system.

9. A vehicle comprising:

the temperature control system of claim 5 ;

a telematics system; and

wherein the HRV controller is further configured to:

transmit data relating to the N HRV parameters, the environmental data and manual setpoint changes to the HVAC system via the telematics system to a remote classification training system; and

receive an updated comfort classification model via the telematics system from the remote classification training system.

10. The temperature control system of claim 5 , wherein the HRV controller is further configured to, in response to a manual setpoint change to the HVAC system, retrain the comfort classification model based on the manual setpoint change.

11. The temperature control system of claim 5 , wherein the HRV controller is further configured to control the HVAC system based on the inter-beat intervals, the environmental data, and the N HRV parameters.

12. A method for controlling temperature in an environment, comprising:

controlling the temperature in the environment using a heating, ventilation and air conditioning (HVAC) system;

generating an electrocardiogram (ECG) signal for an occupant of the environment;

generating environmental data selected from a group consisting of the environmental temperature, an ambient temperature, humidity, sun load and air velocity;

identifying inter-beat intervals based on the ECG signal;

controlling the HVAC system based on the inter-beat intervals and the environmental data;

comparing the inter-beat intervals to a first threshold and a second threshold, wherein the first threshold is less than the second threshold;

increasing heating in the environment when at least one of the inter-beat intervals is less than the first threshold; and

increasing cooling in the environment when at least one of the inter-beat intervals is greater than the second threshold.

13. The method of claim 12 , further comprising controlling the HVAC system further based on variations in the inter-beat intervals.

14. The method of claim 12 further comprising:

adjusting at least one of the first threshold and the second threshold in response to a manual setpoint change to the HVAC system; and

using the adjusted value of the at least one of the first threshold and the second threshold to control the HVAC system.

15. A method for controlling temperature in an environment, comprising:

controlling the temperature in the environment using a heating, ventilation and air conditioning (HVAC) system;

generating an electrocardiogram (ECG) signal for an occupant of the environment;

generating environmental data selected from a group consisting of the environmental temperature, an ambient temperature, humidity, sun load and air velocity;

identifying inter-beat intervals based on the ECG signal;

controlling the HVAC system based on the inter-beat intervals and the environmental data;

comparing a variation in the inter-beat intervals to a predetermined variation threshold;

controlling the HVAC system using a temperature setpoint when the variation is greater than the predetermined variation threshold; and

controlling the HVAC system using a correlation between the inter-beat intervals and comfort of the occupant when the variation is less than the predetermined variation threshold.

16. A method for controlling temperature in an environment, comprising:

controlling the temperature in the environment using a heating, ventilation and air conditioning (HVAC) system;

generating an electrocardiogram (ECG) signal for an occupant of the environment;

generating environmental data selected from a group consisting of the environmental temperature, an ambient temperature, humidity, sun load and air velocity;

identifying inter-beat intervals based on the ECG signal;

controlling the HVAC system based on the inter-beat intervals and the environmental data;

generating N heart rate variability (HRV) parameters based on the inter-beat intervals, where N is an integer greater than one; and

using a comfort classification model defined in a N-dimensional HRV parameter space.

17. The method of claim 16 , further comprising determining comfort of the occupant based on the N HRV parameters and the comfort classification model.

18. The method of claim 17 , wherein the comfort classification model defines at least one comfort region in the N-dimensional HRV parameter space and at least one discomfort region in the N-dimensional HRV parameter space.

19. The method of claim 17 , further comprising training the comfort classification model in response to manual setpoint changes to the HVAC system.

20. The method of claim 17 , further comprising:

transmitting data relating to the N HRV parameters, the environmental data, and manual setpoint changes to the HVAC system via a telematics system to a remote classification training system; and

receiving an updated comfort classification model via the telematics system from the remote classification training system.

21. The method of claim 17 , further comprising, in response to manual setpoint changes to the HVAC system, retraining the comfort classification model.

22. The method of claim 16 , further comprising controlling the HVAC system based on the inter-beat intervals, the environmental data, and the N HRV parameter.