A Home Automation System

516 IEEE Transactions on Consumer Electronics, Vol. CE-3 1, No. 3, August 1985 A HOME AUTOMATION SYSTEM Masahiro Inoue, Kazuho Uemura, Yoshiji Minagawa, Mitsunobu Esaki and Yoshiyuki Honda Consumer Products Research Lab., Mitsubishi Electric Corp. 14-40 Of una 2-chome, Kamakura, 247, Japan ABSTRACT A Home Automation (HA) System based on the Home Bus system has been developed. The system has a multi-layered hierachical struc- ture and is composed of four subsystems (the Room Monitor Control Subsystem, the Telephone Subsystem, the Tele-control Subsystem and the In-house Video Control Subsystem). The HA system has both three inner-subsystem communication codes and one inter-subsystem communication code. The former are optimized for each subsystem and the latter enables the HA system to have efficiently combined applications. A compact (48.6 x 31 x 4 mm) communication control module which interfaces household appliances with the Home Bus has also been developed as one of the key parts for the system. Home Automation (HA) system is an information and control system. It has two seemingly different functions, while they are closely related to each other. Direct (2) Home control and home security function including the control of household appliances which are equipped with communication function. The HA system starts with the security and the telephone system and is required to be expanded into the integrated system which interfaces with ISDN (Integrated Services Digital Network) and twoway CATV etc. The subsystems installed now are requested to have maximum functions in minimum expense and to ensure economical future-expandability simultaneously. The INTRODUCTION (1) two-way CATV, and DBS (Direct Broadcast Sattelite). They have been recently introduced into the commercial market. connection of system possesses a multi-layered hierarchical structure which is composed of subsystems. The application of the structure improved the flexibility and the expandability of the system. A compact communication control module has also been developed for this system. home to information sources by means of new broadcast and tele-communications such as videotex, Manuscript received June 10, 1985. HA 0098-3063/85/0800-0516$01.00 © 1985 IEEE Inoue, et al.: A Home Automation System 2. 517 THE CONSTRUCTION OF THE HOME BUS Home Bus is a common medium through which distributed located equipment in house communicate with each other. A domestic and international standard of Home Bus is required to construct Home Automation Systems which are: composed of many types of equipment made by different manufacturers. In Japan, studies to standardize Home Bus are held by the Ministry of International Trade and Industry, the Ministry of Post and Telecommunication, the Kansai Electronics Industries Development Center (K.E.C.), Electronic Industries Association of Japan (E.I.A.J.) and Japan Electric Manufacturers Association (J.E.M.A.). We also study group participate in these to standardize the home bus system. The standard specification is not yet determined, therefore in the present Home Automation System, Base-band digital communication protocol only followed the proposal 2.1 ) of Murata et al. CHANNEL HOME BUS ALLOCATION OF THE of media The transmission of the Home Bus System consist a coax and a pair of metallic wires. Figure 1 shows channel allocation of the Home Bus. The coax is prepared to transmit digital data, audio and video signals generated in house and broadcast. The metallic wire is mainly for telephone signals. IN-HOUSE VIDEO CONTROL SIGNAL COAX CABLE BASEBN SBA 10 I0 BROADCAST FM TV- BAND 75 76 FREQUENCY (MHz) PHONE METALLIC WIRE 0 Fig. 1 FREQUENCY (M) Channel Allocation System of The Digital control signal (Baseband), video signal (Sub-band) and broadcast (FM-TV-band) are frequency divided multiplexed in the coax cable. Video signal in-house from video sources such as picture phone sentry is modulated at radio freThe quency (10-75 MHz). signal transmitted up to the Head-End, is in which the carrier frequency is converted into UHF and the converted signal is received by conventional TV sets distributed on the Home Bus. 2.2 BASE-BAND SPECIFICATION Base-band channel is prepared for digital control signal transmission. The specification of the channel is required to be flexible enough to apply to home security system, home control system, telephone system and personal computer communication in house. We followed the proposal )of Murata et al, because it is flexible enough for such applications. The Physical Layer and The Data Link Layer specification of the Home Bus are: IEEE Transactions on Consumer Electronics, Vol. CE-31, No. 3, August 1985 518 Physical Layer Data rate: 9,600 bits/sec 200 separation: station Maximum meters Maximum number of stations: 255 base-band cable, Coaxial Medium: signalling Topology: Bus Line level: 0 to 5 volts Transmission logic: Positive Synchronization: Asynchronous Data link layer control Link Frame format: SA CW DA SA DA CW BC DATA FCC : : : : : : procedure: BC DATA CSMA/CD FCC FUNCTIONS The module supports the Physical Layer and the Data Link Layer of The functions of the Home Bus. the module are: data encapsulation (1) Transmit (2) Transmit link management (3) Receive data decapsulation (4) Home Bus tranceiver (5) Host system interface. The module has two execution Module information the modes: The the Control Module. and bits 8 has Module Information data bus and handshake lines which with interface to are prepared a as such personal a host system computer and a home controller. Source address Destination address Control word Number of data Data Frame check code Error detection: Parity & FCC Frame priority: 4 levels Collision detection: Bit verification for each bit period 3. 3.1 DATA ~(HAND SHAKE OBF HOST SYSTEM IF COMMUNICATION CONTROL MODULE The Home Bus System consists Home Bus and equipment distriof buted located in a house. which A communication interface, connects a piece equipment with Home Bus, is indispensable for the system. is required interface The is apit because to be low cost, of the all equipment plied to system. A Communication Control Module for the Home Automadeveloped was The module supports tion System. and the Data the Physical Layer and of communication, Link Layer a on is combined compact hybrid integrated circuit. ACK IBF STB ERR DAS TX RX MSEL R RION HOME BUS ,MODE SELECT PRION I ADDRESS Fig. 2 Block Diagram of Communication Control Module Figure 2 illustrates a block diagram of the Information Module, which has data bus, handshake lines (OBF, ACK, IBF, STB, ERR, DAS), Mode ports, input self address Select inputs (MSEL, BROD, PRINO, PRION1) and Home Bus interface (TX, RX). procedure, transmission In after the Information Module receives destination address and data from the host system, the module assembles a frame and generates a frame check code. The frame is transmitted 519 Inoue, et al.: A Home Automation System the destination station, which receives the frame and disassembles the frame in order to transfer to a data destination received host system. The Control Module has both 8 bits lached output ports and 8 bits input ports which are prepared to input status of sensors and switches and to control loads such as light respectively. The Control Module can handle only a single byte data frame but requires no host system. The input port data are automatically transmitted to an Intermation Module which intermaster a controller faces with in each application. to Figure 3 shows the Communication Control Module. The module is composed of a CMOS 8-bit single-chip microcomputer, a tranceiver circuit with 400 mA current driver and CMOS multiplexers. All the circuits are combined on one compact (48.6 x 31 x 4 mm) hybrid integrated circuit. The power consumption is less than 100 mW. The tranceiver is open collector output which enables adjustment of load in order to suit impedance of the BUS. Transmission in the Home Bus with the module has been examined and proved reliable enough. 4. 3.2 4.1 CONSTRUCTION SYSTEM ARCHITECTURE LOGICAL STRUCTURE The HA system has a multi-layered hierarchical structure composed of distributed controlled subsystems. Figure 4 shows the logical structure of the HA system. All the equipment is distributed on the Home Bus and communicate with each other. Fig. 3 Communication Control Module TELE-CONTROL TELEPHONE SUBSYSTEM SUBSYSTEM Fig. 4 Each subsystem, consisting of one or several types of equipment, has its own optimized communication code. The common communication code was determined to support inter-subsystem communication. ROOM MONITOR CONTROL SUBSYSTEM Hierarchical The HA System IN-HOUSE VIDEO CONTROL SUBSYSTEM Structure of 520 IEEE Transactions on Consumer Electronics, Vol. CE-3 1, No. 3, August 1985 This hierarchical structure composed of subsystems offers these advantages: (1) Each subsystem can operate individually. (2) Integration of subsystem realizes efficiently combined application of subsystems. (3) A system down of one system does not directly cause another system's down. (4) Optimized inner-subsystem codes need only small hardware and small software. The whole system is composed Control of the Room Monitor Subsystem, the Telephone Subsystem, the Telecontrol Subsystem and the In-house Video Control Subsystem. The Room Monitor Control Subsystem supports home security and home control functions. The system consists of the Room Monitor Controllers (RMCs) and the Main Monitor Controllers (MMCs). The RMC each located in is distributed and control room to appliances monitor sensors in each room. The MMC is a remote control and monitor unit of RIAC appliances. Telephone Subsystem is composed of a master controller and telephones. The subsystem supports security alarm by synthesized voice as well as telephone function. Tele-control The Subsystem has both tele-control and telemonitor which with functions cooperate the RMC subsystem in order to control appliances and tele-monitor security sensors by telephones out of house. The In-housse Video Controller (VC) and a Home Monitor TV set and Picture Phone Sentry (PPS). The Home Monitor TV is controlled by the VC in order to receive video signals from the PPS and the securityalarm broadcast generated by VC which are transmitted through the Bus as UHF signals in house. ROOM MONITOR CONTROLLER MAIN MONITOR CONTROLLER RMC MMC Fig. 5 Logical Communication Links Figure 5 indicates the logical communication links of the system. Each subsystem consists of a Master unit or consists of both Master units and Slave units. The Master unit communicates information with another Master unit which belongs to different subsystem. The Slave units are inhibited from communicating with both the Master units and the Slave units which belong to different subsystems. 4.2 PHYSICAL STRUCTURE structure of The physical the system, which contains both of specification configuration of units and function-distribution among the units, was designed to and ensure future-expandability reliability of the system. 521 Inoue, et al.: A Home Automation System TELE-CONTROL TELEPHONE ROOM MONITOR CONTROL SUBSYSTEM SUBSYSTEM SUBSYSTEM Fig. 6 Fig. 7 IN-HOUSE VIDEO CONTROL SUBSYSTEM Physical Structure of The HA System Main Panel of The HA System Figure 6 indicates the physical structure of the system. Each piece of equipment is interfaced with the Home Bus which is composed of a metallic wire and a coax cable which is The terminated at the Head-End. Subsystem Monitor Control Room has two types of master: one is the MMC and another is the master RMC. The master RMC has both the Slave function (controlling loads and monitoring sensors in local function and the Master room ) (communicating with masters which belong to different subsystems). The master unit of the Telephone subsystem and that of the Telecontrol subsystem share a hardware, because they require some of the same functions such as a voice synthesizer and a network control unit. Figure 7 shows a main panel of the Home Automation System, which is combined panel of units which belongs to three subsystems, that is, the Room Monitor Control SubSubsystem the Telephone system, the Subsystem. Tele-control and IEEE Transactions on Consumer Electronics, Vol. CE-3 1, No. 3, August 1985 522 4.3 4.3.1 SYSTEM PROTOCOL COMMUNICATION CODE SYSTEM The communication code system of the Home Automation System is divided into two categories, that is, the Inter-subsystem Communication Codes and the Inner-subsystem InterThe Code. Communication subsystem Communication Code was defined for master units to communicate with each other. The communication using the codes realizes efficiently combined application among the subsystems. The Inner-subsystem Codes were defined Communication for both master and slave controllers in an identical subsystem to communicate with one another. The Inner-subsystem Communication Code is small enough to reduce the cost of slave units (Table 1). Table I COMMUNICATION CODE SYSTEM SUB SYSTEM CODE Fig. 8 Communication Code System phone (master) and the VC have the capability of encoding and decoding both the Inter- and the Inner-subsystem Code. The MMC and the Teleslave which has no controller, unit, supports only the Inter-subsystem Code. INTER-SUBSYSTEM CODE SHORT CODE LONG CODE SHORT FRAME LONG FRAME SMALL HARDWARE FLEXIBILITY SMALL SOFTWARE FUTURE EXPANSION SMALL COMMUNICATION BUFFER MEMORY Figure 8 indicates the communiThe center code system. cation is the Inner-subsystem communication code and the surroundings are Intersubsystem Codes consisting of three sets of codes, that is, the Room Code, Subsystem Control Monitor the Telephone Subsystem Code and the In-house Video Control Subsystem Code. The RMC (master), the Tele- 4.3.2 THE INTER-SUBSYSTEM CODE SA DA CW BC DATA MU FR RT * SA: * DA : * CW: * BC: ° DATA 10 ST SOURCE ADDRESS DESTI NATION ADDRESS CONTROL NUMBER MU: FR: RT :7 10: ST: * FCC: FRAME Fig. 9 FCC WORD OF DATA MULTICAST-GROUP CODE FRAME CHARACTERISTIC CODEF ROOM / TERMINAL CODE IO CODE STATUS CODE CHECK CODE (CHECK SUM) Inter-subsystem Frame Format Inoue, et al.: A Home Automation System The frame format of the Interis subsystem Code indicated in figure 9. The data field is divided into five fields, that is, the Multicast Group Code field, the Frame Characteristic Code field, the Room/Terminal Code field, the 10 Code field and the Status Code field. Each code is defined as follows: (1) (2) (3) (4) (5) Multicast Group Code This code specifies the range of multicast. The Communication Control Module recognizes and accepts any frame whose destination field contains the broadcast address (DA=OOH). The host system should be designed to reject any frames whose Multicast Code Group does not contain the group code which specifies the host system. Useful multicast groups for example, "All the are, units in an identical subsystem" and "All master units of all subsystems". Frame Characteristic Code This code specifies the duty of the frame in applications. The of duties frames are, for example, "Report", "Control "Monitor command" command", and "Answer". Room/Terminal Code This Code specifies logical destination host in "Control command" or "Monitor command" frame and logical source host in "Report" or "Answer" frame. I/O Code This code specifies appliances or functions which are under supervision of a host system. The code contains, for example, "Air conditioner", and "Heat detector". Status Code This code status specifies of I/O (appliances or funcThe code indicates tions). 523 the action (turn on/off, set level) in "Control command" and status of appliances in "Answer to monitor-request". 4.3.3 PUBLIC COMMUNICATION PROCEDURE TELECONTROLLER RMC (MASTER) RMC (SLAVE) )CONTROL AIR CONDITIONER R M C : ROOM MONITOR CONTROLLER Fig. 10 Communication Procedure Figure 10 demonstrates communication procedure of tele-control of an air conditioner. The control command (PB signal) from a public telephone is transmitted to the Tele-controller of the The system. PB received signal is converted into communication code of the system in the Tele-controller. The Tele-controller assembles a frame composed of the Inter-subsystem code. The frame is transmitted to the RMC (master), which converts the received code into a inner-subsystem code. The frame consisting of a inner-subsystem code is transmitted to the RMC (slave), which decodes the code and control air conditioner. Then the RMC (slave) transmits a response frame to the RMC (master), which converts the code into a inter-subsystem code and relays the frame to the TeleThe controller. Tele-controller decodes the received code and reports of the status of air conditioner by synthesized voice. 524 IEEE Transactions on Consumer Electronics, Vol. CE-31, No. 3, August 1985 5. CONFIGURATION 5.1 OF SUBSYSTEMS (5) ROOM MONITOR/CONTROL SUBSYSTEM cOAx RMc KITCHEN SENIORS111 LIOHIT AIR CONDRTIO1ER S VALVE RMC mmEMCROOM RMC SENSOR SEti- NSOR SENSORS LIGHT LIGHT LOCK BATH ROOM LIGHT AI CONDTIONER DIREC TOAL RUC FNTRANWE MAIN momrr COl lIOLLER| ISPLAY LIFE-STYLE SWITCH COUPLER FILTER Room MONITO CONT SRANCINS RMC Fig. 11 Room R: Monitor sensors. Receiving command'" "Control and "Report" frames and controlling the appliances and activating alarm. The RMCs are distributed control units and exchange room information with each other. The system structure has these advantages: (1) Construct system which contains from one RMC to 13 RMCs without initial adjustment. (2) Add RMCs to the system without adjustment. (3) Troubles of an RMC cause little damage to the whole system. (4) Control and monitor appliances and sensors even in case of Home Bus trouble. Control Subsystem The Room Monitor Control Subsystem supports home security and home control functions. The system four types of consists of RMCs (Kitchen, Bedroom, Bathroom, EnMMCs. Figure 11 and trance) illustrates the system configuration of the Room Monitor Control SubThe RMCs are distributed system. located in each room to control and monitor sensors appliances The MMC operates in each room. as a remote control and monitor unit of the appliances under supervision of RMCs. The minimum system consists of a single RMC whose functions are: (1) Watching (4) heat detector and and giving alarm in case of emergencies. control of appliances, for example, lights, an air conditioner, and an electric lock. Automatic control of appliances in case of emergencies. Transmitting frames reporting status of appliances and (2) Manual (3) a a gas detector etc. 5.2 TELEPHONE SUBSYSTEM D:DIRECTIONAL COUPLER : Fig. 12 RANMOIN FILTER Telephone Subsystem Figure 12 shows the Telephone which of Subsystem, consists a telephone (master) and telephones (maximum 8 units) and a door phone or a PPS. The Telephone Subsystem has only telephone and intercom functions but also security functions which are closely related to the RMC subsystem. not Inoue, et al.: A Home Automation System 525 When the heat detector is activated, the RMC (master) informs the Telephone (master) of fire. The Telephone (master) synthesizes voice of reporting fire. The voice is transmitted to all Telephones by the Home Bus. Each Telephone outputs the voice with a loudspeaker. 5.3 TELE-CONTROL SUBSYSEM The Tele-control subsystem supports controlling and monitoring both the appliances and sensors under supervision of the RMCs via public telephone line from telephones out of home. All the instructions are transmitted in PB signals and all the answers are returned with aynthesiz- ed voice generated by the Tele-controller. 5.4 IN-HOUSE VIDEO CONTROL SUBSYSTEM TV set, the PPS and TV printer. The Home Monitor TV set has a remote controlled tuner system, which is controlled by the VC in order to receive video signal from the PPS and the security-alarm broadcast which are transmitted through the Bus as UHF signals in house. The TV printer outputs the pictures of guests which are taken by the PPS under supervision of the VC. The PPS is equipped with both an infra-red camtera and lights so that it can take a picture in total darkness. 6. CONCLUSION A Home Automation System based Bus system developed. a multi-layered The system has hierachical structure composed of subsystems. A compact communication control module was developed as one of the key parts for the system. on the Home ACKNOWLEDGEMENT The authors would like to express their appreciation to Kiyoto Ohkawa, Mizuho Yamasaki and Manabu Fujii for their continuous encouragement. REFERENCES VIDEO CONTROLLER . PICTURE PHONE TV PRINTER HOME MONR TV SENTRY 1. M. Murata, T. Namekawa, and R. Hamabe, "A PROPOSAL FOR STANDARDIZATION OF HOME BUS SYSTEM FOR HOME AUTOMATION", IEEE Trans. on CE, Vol. CE-29, No. 4, 1983 DIRECTIONAL COUPLER BRANCHING Fig. 13 FILTER In-house Video Control Subsystem the illustrates 13 Figure Control Video In-house Subsystem which consists of the Video ConMonitor Home the troller (VC), 2. Kazuyuki Yamamoto and Nobuhisa Ayugase, "A HOME TERMINAL SYSTEM USING THE HOME AREA NETWORK", IEEE Trans. on CE, Vol. CE-30, 1984 3. Yoshiji Minagawa, Kazuho Uemura, Mitsunobu Esaki Masahiro Inoue, and Manabu Fujii, "A HOME INFORMATION-NETWORK Mitsubishi SYSTEM", Denki Giho, Vol. 58, No. 9, 1984 526 IEEE Transactions on Consumer Electronics, Vol. CE-31, No. 3, August 1985 BIOGRAPHIES Masahiro Inoue received his B.S. and M.S. degrees from Waseda University, Tokyo, Japan in 1978 and 1980 respectively. He joined the Product Development Laboratories, Mitsubishi Electric Corporation, where he was concerned with the development of optical communication in home control electronics. Since 1983 he has been with the Consumer Products Research Laboratory, where he has been engaged in the development of home automation systems. He is a member of the Institute of Electronics and Communications Engineers of Japan. Kazuho Uemura received his B.S. and M.S. degrees from Tokyo Institute of Technology, Tokyo, Japan in 1977 and 1979 respectively. He joined the Consumer Products Research Laboratory, Mitsubishi Electric Corporation, where he is engaged in the development of home computers and home automation systems. He is a member of the Information Processing Society of Japan. Yoshiji Minagawa graduated from technical school in 1969. He joined the Ofuna Works, Mitsubishi Electric Corporation, where he was concerned with the development of lighting control systems, Since 1983 he has been with the Consumer Products Research Laboratory, where he has been engaged in the development of home automation systems. He is a member of the Illuminating Engineering Society. 527 Inoue, et al.: A Home Automation System Mitsunobu Esaki graduated from technical school in 1965. In 1965 he joined the Consumer Products Research laboratory, Mitsubishi Electric Corporation, where he was concerned with radiation noise of electric equipment from 1965 to 1972, and development control for microcomputer systems air conditioning and refrigerating equipment from 1972 to 1983. Since 1983 he has been engaged in the development of home automation systems. Yoshiyuki Honda received his B.S. degree in 1966 from Nagoya Institute of Technology, Nagoya, Japan. He then joined the Consumer Products Research Laboratory, Mitsubishi Electric Corporation, where he has been engaged in the development of the electronic controllers for household appliances using one chip microcomputers. Recently, he takes an interest in the standardization activitites of Home Bus Systems and also takes part in some of these activities in Japan. He is presently a manager of Home Control and Information Systems Group. He is a member of the Institute of Electrical Engineers of Japan and the Institute of Electronics and Communications Engineers of Japan.