A system for communicating across conventional HVAC wiring is provided. The system includes a communication device having a communication module capable of inducing low power, high frequency current signals into a single control wire coupling, for example, a thermostat with a compressor. The communication module includes a power supply module that draws power sufficient to operate the communication module from the existing HVAC wiring, so as to eliminate any need for batteries or external power sources. A second communication module may be coupled to the single control wire. The second communication module operates as a transceiver sending communication signals to, and receiving communication signals from, the communication module. In one embodiment, the communication module is disposed within a building, for example coupled to an electronic thermostat, while the second communication module is disposed outside the building near the compressor. The communication signals are RF modulated signals between 5 and 50 MHz so as to take advantage of and pass across parasitic capacitances found inherent in transformers or other coils disposed within HVAC loads.

HVAC Communication System

An air conditioner for vehicles includes a damper for switching among an outside-air inlet mode, an inside-air inlet mode and an outside/inside-air inlet mode, a manual switch for selecting any one of the respective inlet modes, an automatic switch for automatically selecting one of the respective inlet modes, a heating and cooling operation unit, an inside-air temperature sensor, an outside-air temperature sensor and a control unit for selectively controlling the respective inlet modes based on the condition of the heating and cooling operation unit, the condition of the respective switches and the difference between the temperatures detected by the respective temperature sensors. In the air conditioner, an optimum air conditioning in correspondence to the load required for air conditioning can be realized from the viewpoint of saving of energy and efficient operation.

Air conditioner for vehicles

A microcomputer based clock operated thermostat is operated to adjust a ramprate of a setpoint temperature upon a setpoint change The microcomputer in the thermostat is capable of determining the amount of overshoot or undershoot between the air temperature and the desired setpoint temperature by utilizing a sensor temperature of the thermostat, and computing a variation in the pickup ramprate to bring the overshoot within an acceptable level

Thermostat means adaptively controlling the amount of overshoot or undershoot of space temperature

A strategy for controlling an air side economizer of an HVAC system uses a model of the airflow through the system to estimate the load in two modes when minimum and maximum amounts of outdoor air are being introduced into the building. Transitions between minimum outdoor air and maximum outdoor air usage occur based on those estimated loads, which in a preferred embodiment are cooling loads. The second embodiment of this economizer control strategy uses the model and a one-dimensional optimization routine to determine the fraction of outdoor air that minimizes the load on the HVAC system.

Model based economizer control of an air handling unit

An operating system for a dual fuel heating system having first and second heat pump stages, first and second gas furnace stages, an executive controller for tracking time increments and call control strategies at appropriate levels, a demand control for calculating the amount of time each heat pump can be on during a predetermined time window, a data storage apparatus, a thermostat, a first predicting module for predicting non-heat pump electrical load based on a moving average, a second predicting module for predicting heat load based on a moving average, and a limiting module for setting demand limits for off-peak, mid-peak and peak periods. The executive controller is operated to initiate operation of the foregoing routines to determine, based on historical building profile information including non-heat pump electric power information the availability of heat pump power with no increase in demand charges during any given incremental interval. In a further aspect of the invention, break even points are calculated to determine the economic feasibility of increasing the demand set point incrementally in a dual fuel system. The system integrates intelligent demand logic and conventional thermostat logic algorithms into a dual fuel control system.

Dual fuel heat pump controller

An air conditioning system furnishing temperature conditioned air to a plurality of zones each of which has its own zone damper controlled by its own space thermostat. The system has an air discharge temperature sensor downstream of the temperature conditioning heat exchanger which is connected to a microprocessor controller for controlling a plurality of stages of temperature conditioning apparatus such as heating or cooling apparatus and a damper motor control for controlling the entry of outdoor air into the system. A reset thermal comfort sensor located in a representative zone or area is connected to the microprocessor controller for varying the controlled temperature of the supplied discharge air by operating the outdoor air damper motor and the multi-stage temperature conditioning apparatus to maintain the best use of outdoor air for cooling and the most efficient operation of refrigeration cooling apparatus by ensuring maximum air delivery to the heat exchangers during the operation of the mechanical cooling apparatus.

Microprocessor discharge temperature air controller for multi-stage heating and/or cooling apparatus and outdoor air usage controller

A multistage thermostat means that is adapted for use with equipment such as a heat pump and auxiliary heat and which effects efficient operation upon a temperature setup after a nigh setback function by introducing an exponential change in the apparent control setpoint. The sensitivity of the signal processing channel of the system is altered to maintain stability. The system further contains a power-up reset function that also alters the signal processing channel for rapid reestablishment of normal control.

Multistage thermostat using multirate integral action and exponential setpoint change

As part of the Intelligent Task Automation program, a team developed enabling technologies for programmable, sensory controlled manipulation in unstructured environments. These technologies include 2-D/3-D vision sensing and understanding, force sensing and high speed force control, 2.5-D vision alignment and control, and multiple processor architectures. The subsequent design of a flexible, programmable, sensor controlled robotic assembly system for small electromechanical devices is described using these technologies and ongoing implementation and integration efforts. Using vision, the system picks parts dumped randomly in a tray. Using vision and force control, it performs high speed part mating, in-process monitoring/verification of expected results and autonomous recovery from some errors. It is programmed off line with semiautomatic action planning.

Ronald Benton

Papers

Microprocessor discharge temperature air controller for multi-stage heating and/or cooling apparatus and outdoor air usage controller

Multistage thermostat using multirate integral action and exponential setpoint change

Implementation of a robotic flexible assembly system