Adaptive recovery control scheme for conventional and heat pump systems

• US 5,622,310 A
• Filed: 07/21/1995
• Issued: 04/22/1997
• Est. Priority Date: 07/21/1995
• Status: Expired due to Term

• Current Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Original Assignee: Honeywell Incorporated (Honeywell International Inc.)
• Inventors: Meyer, Jeffrey R.
• Primary Examiner(s): Wayner, William E.
• Application Number:
  US08/505,505
• Time in Patent Office: 641 Days
• Field of Search: 62/231, 236/46 R, 236/47, 165/239, 165/241
• US Class Current: 236/46.00R
• CPC Class Codes: G05D 23/1904 variable in time

Abstract

An adaptive recovery process and apparatus for use in temperature control devices for controlling different kinds of HVAC plants. The process and apparatus include main and auxiliary heat ramps in the adaptive recovery portion for dealing with both conventional and auxiliary stages within one process and apparatus.

Claims

1. A thermostat having system, heating, cooling and fan control capabilities for a plurality of types of HVAC plants, comprising:

a temperature sensor producing a temperature signal representative of space temperature;

a microprocessor having internal memory and producing a current time signal;

read only memory connected to the microprocessor, the read only memory storing time and temperature pairs and an adaptive recovery process used by the microprocessor for achieving a desired temperature by a target time, the microprocessor determining a time until temperature change value based on the time and temperature pairs and the current time signal, a main ramp, an auxiliary ramp and comparing the temperature signal to the main ramp and the auxiliary ramp, the memory further storing a table of system states and system events and process flags, the microprocessor internal memory storing a current state from the system states and current status of process flags, the microprocessor causing a desired state to occur and setting/clearing of a process flag according to a state-event pair from the table on the occurrence of one of the events.

2. A temperature control device for controlling the operation of an HVAC plant such that a desired temperature is maintained, comprising:

a user interface having a first microprocessor, first read only memory and a temperature sensor connected to the first microprocessor, the first microprocessor controlling the operation of the user interface, the first read only memory storing time and temperature pairs for control of the HVAC plant entered by a user through the data entry means, the first microprocessor producing a time until temperature signal based upon the time and temperature pairs and the current time, the temperature sensor producing a temperature signal representative of space temperature; and

a subbase electrically connected to the user interface and having a second microprocessor having internal memory and second read only memory, said second read only memory storing an adaptive recovery process used by the second microprocessor for achieving a desired temperature by a desired time, the second microprocessor receiving the time until temperature change signal and creating, a main ramp, an auxiliary ramp and comparing the temperature signal to the main ramp and the auxiliary ramp, the memory further storing a table of system states and events and process flags, the microprocessor internal memory storing a current state from the system states and current status of process flags, the microprocessor causing a desired state to occur and setting/clearing of a process flag according to a state-event pair from the table on the occurrence of one of the events.

3. A method of adaptive temperature recovery in a temperature control device, comprising the steps of:

determining a current actual temperature;

producing a current time signal;

producing a time until temperature signal based on the current time signal and stored time temperature pairs;

producing a main ramp having one point fixed at a next time and temperature pair and having a slope which is initially at a preselected value;

producing an auxiliary ramp having one point fixed at a next time and temperature pair and having a slope which is a predetermined factor of the slope of the main ramp

storing a current state and current status for a plurality of process flags;

waiting for an event to occur;

modifying the current state and current status of the process flags appropriately based upon state-event-process flag table;

updating the slope of the main ramp when enabled by appropriate status of a process flag by determining whether a target temperature was reached late or on time-early, and modifying the slope as a function of the old slope, the difference between the target temperature and the actual temperature at the target time if the process was late, otherwise modifying the slope as a function of the old slope and the time until temperature at the point the target temperature is reached; and

modifying the slope of the auxiliary ramp as a function of the slope of the main ramp.