Masterless air handler unit (AHU) controller system

Patent metadata

Field	Value
Publication number	US-10619880-B2
Application number	US-201815964798-A
Country	US
Kind code	B2
Filing date	Apr 27, 2018
Priority date	Apr 27, 2018
Publication date	Apr 14, 2020
Grant date	Apr 14, 2020

Abstract

A masterless building device system for controlling an environmental condition of a building, includes a first building device and a second building device. The first building device includes a first processing circuit configured to determine, via a first sensor of the first building device, a first environmental condition value of the environmental condition. The first processing circuit is configured to broadcast the first environmental condition value to a second building device via a network. The first processing circuit is configured to receive, via the network, a second environmental condition value broadcast by the second building device, generate a calculated environmental condition value based on the first environmental condition value and the second environmental condition value, and control the environmental condition based on the calculated environmental condition value.

First claim

What is claimed is:

1. A masterless building device system for controlling an environmental condition of a building, the system comprising:
a first building device comprising a first processing circuit configured to:
determine, via a first sensor of the first building device, a first environmental condition value of the environmental condition;
broadcast the first environmental condition value to a second building device via a network;
receive, via the network, a second environmental condition value broadcast by the second building device;
generate a calculated environmental condition value based on the first environmental condition value and the second environmental condition value; and
control the environmental condition based on the calculated environmental condition value; and

the second building device comprising a second processing circuit configured to:
determine, via a second sensor of the second building device, the second environmental condition value of the environmental condition;
broadcast the second environmental condition value to the first building device via the network;
receive, via the network, the first environmental condition value broadcast by the first building device;
generate the calculated environmental condition value based on the first environmental condition value and the second environmental condition value; and
control the environmental condition based on the calculated environmental condition value.

2. The system of claim 1 , wherein the first processing circuit is configured to generate the calculated environmental condition value by averaging the first environmental condition value and the second environmental condition value.

3. The system of claim 1 , wherein the network is a token network wherein a token is passed between the first processing circuit and the second processing circuit, wherein the first processing circuit and the second processing circuit are configured to broadcast messages on the network in response to receiving the token;
wherein the first processing circuit is configured to broadcast the first environmental condition value to the second building device via the network by:
marking a message comprising the first environmental condition value as high priority and adding the message to a message queue comprising a plurality of other messages;
receiving the token via the network;
broadcasting the message via the network before broadcasting the plurality of other messages via the network in response to determining that the message is marked as high priority and in response to receiving the token.

4. The system of claim 1 , wherein the first processing circuit is configured to receive, via the network, the second environmental condition value broadcast by the second building device by:
receiving the second environmental condition value of the second building device via a broadcast; and
determining whether a group identifier of the broadcast matches a group identifier of the first building device;
wherein the first processing circuit is configured to generate the calculated environmental condition value based on the second environmental condition value in response to determining that the group identifier of the broadcast matches the group identifier of the first building device.

5. The system of claim 1 , wherein the first building device is a first air handler unit (AHU) and the second building device is a second AHU.

6. The system of claim 5 , wherein the first processing circuit is configured to:
receive an indication that the first AHU has been activated;
receive, via the network, a supply fan amount broadcast by the second AHU;
generate a calculated supply fan amount based on the received supply fan amount and one or more other supply fan amounts received from other AHUs;
ramp a speed of a supply fan of the first AHU to the calculated supply fan amount over a time period without performing a control process; and
perform the control process in response to determining that the speed of the supply fan has reached the calculated supply fan amount.

7. The system of claim 1 , wherein the first processing circuit is configured to:
receive a first setpoint value for the environmental condition and generate a timestamp for the first setpoint value based on a time at which the first setpoint value is received;
broadcast the first setpoint value to the second building device via the network;
receive, via the network a second setpoint value broadcast by the second building device and generate a second timestamp for the second setpoint based on a time at which the second setpoint value is received; and
select a most recent setpoint value from the first setpoint value and the second setpoint value based on the first time stamp of the first setpoint value and the second timestamp of the second setpoint values;
wherein the first processing circuit is configured to control an actuator of the first building device to control the environmental condition based on the calculated environmental condition value and the selected most recent setpoint value.

8. The system of claim 7 , wherein the environmental condition comprises a pressure of a supply duct of the building and the setpoint comprises a supply duct pressure setpoint;
wherein the first building device is a first roof top unit (RTU) located on a rooftop of the building and the second building device is a second RTU located on the rooftop of the building.

9. A first building device of a building for operating in a masterless building device system comprising one or more second building devices, the first building device comprising:
an actuator configured to control an environmental condition of the building;
a sensor configured to sense the environmental condition of the building; and
a controller comprising a processing circuit configured to:
determine, via the sensor, a first environmental condition value of the environmental condition;
broadcast the first environmental condition value to the one or more second building devices via a network, wherein the one or more second building devices are each configured to control the environmental condition based on the broadcasted first environmental condition value;
receive, via the network, one or more second environmental condition values broadcast by the one or more second building devices;
generate a calculated environmental condition value based on the first environmental condition value and the one or more second environmental condition values; and
control the actuator based on the calculated environmental condition value to control the environmental condition of the building.

10. The first building device of claim 9 , wherein the processing circuit is configured to generate the calculated environmental condition value by averaging the first environmental condition value and the received one or more second environmental condition values broadcast by the one or more second building devices.

11. The first building device of claim 9 , wherein the processing circuit is configured to broadcast the first environmental condition value to the one or more second building devices via the network by broadcasting the first environmental condition values at a broadcast rate, wherein the broadcast rate is the same as or less than a control process execution rate, wherein the control process execution rate indicates the rate at which the processing circuit is configured to generate a control output for controlling the actuators based on the calculated environmental condition value.

12. The first building device of claim 9 , wherein the processing circuit is configured to:
generate a time stamp for e

Assignees

• Johnson Controls Tech Co

Inventors

• Ritmanich Kraig D
• Amundson Christopher R
• Seiler Aron M

Classifications

• G05D23/1934

  each space being provided with one sensor acting on one or more control means · CPC title

• F24F11/46

  Improving electric energy efficiency or saving · CPC title

• F24F11/74

  for controlling air flow rate or air velocity · CPC title

• F24F11/54 Primary

  using one central controller connected to several sub-controllers · CPC title

• F24F2110/10

  Temperature · CPC title