1 Introduction
The digital home is the basic unit of future smart community systems. A "digital home" is one that provides intelligent services covering the entire home based on an internal home network, including data communication, home entertainment, and information appliance control functions.
A key aspect of digital home design is the implementation of communication functions, including communication between the home and the outside world, as well as communication between related facilities within the home. Currently, external communication primarily relies on broadband internet access, while for internal home communication, the author utilizes Bluetooth wireless access technology, which is currently quite competitive.
Traditional digital homes rely on PCs for overall control, which lacks a human touch. Based on the concept of artificial emotions, this paper designs an intelligent robot equipped with various external sensors, treating this robot as a family member to control the digital home.
This paper mainly focuses on the model design of intelligent robots in digital home healthcare. Bluetooth technology is used for communication between the intelligent robot, medical instruments, and the control PC. The entire system has low cost, comprehensive functions, and a wide range of applications, demonstrating significant market potential.
2. Overall Design of Intelligent Robot
2.1 Multi-sensor system for intelligent robots
The most important related field in robot intelligence technology is the integration and fusion of the robot's multi-sensory system and multi-sensory information [1], which are collectively referred to as the hardware and software parts of the intelligent system. The fusion of external sensors such as vision, hearing, force, and touch, and internal sensor information of each joint of the robot can enable the robot to perform important functions such as real-time image transmission, voice recognition, scene identification, positioning, automatic obstacle avoidance, and target detection. Adding relevant medical modules (CCD, CAMERA, stereo microphone, image acquisition card, etc.) and dedicated medical sensor components to the robot, along with a medical expert system, can realize medical care and remote medical monitoring functions. The block diagram of the multi-sensor system of the intelligent robot is shown in Figure 1.
2.2 Intelligent Robot Control System
The robot control system consists of two parts: one is the host computer, which is usually a PC, and it completes tasks such as robot motion trajectory planning, sensor information fusion control algorithms, vision processing, human-machine interface and remote processing; the other is the slave computer, which usually uses a multi-microcontroller system or DSP as the core component of the controller, and completes functions such as motor servo control, feedback processing, image processing, voice recognition and communication interface.
If a multi-microcontroller system is used as the lower-level machine, each processor completes a single task and completes the overall system function through information exchange and mutual coordination, but it is obviously lacking in signal processing capability. Since DSP is good at signal processing, and intelligent robots often need signal processing, image processing and speech recognition, DSP is used as the controller of the intelligent robot control system [2].
The control system is based on a DSP (TMS320C54x) as its core component and consists of Bluetooth wireless communication, GSM wireless communication (supporting GPRS), motor drive, digital compass, sensory function sensors (vision and hearing, etc.), medical sensors, and a multi-select serial communication (RS-232) module. The block diagram of the control system is shown in Figure 2.
(1) The system controls the movement of the robot by driving motor and steering motor. The steering motor uses the information from the digital compass as feedback for PID control.
(2) The ROK101007 circuit of Ericsson is used as the Bluetooth wireless communication module to realize the communication between the intelligent robot and the host computer Pc and the communication with other medical and health care instruments based on Bluetooth modules.
(3) The GSM wireless communication module that supports GPRS supports data, voice, SMS and fax services and communicates with the remote medical monitoring center using mobile phone communication.
(4) Since the TMS320C54x only has one serial port, and the Bluetooth module, GSM wireless module, digital compass, and sensor modules for visual and auditory functions all use RS-232 asynchronous serial communication, a multi-select serial communication module must be designed for conversion. When the TMS320C54x needs data from the Bluetooth wireless communication module, it selects it through the circuit; when the TMS320C54x needs data from a certain sensor module, it disables the previous wireless communication module selection and simultaneously selects the current sensor module. In this way, each module completes serial communication with the TMS320C54x.
3. Realization of key healthcare functions
Intelligent robots can provide the following services for healthcare in the digital home:
(1) Medical monitoring
Medical sensors with integrated Bluetooth modules are used to monitor key physiological parameters of family members in real time, such as electrocardiogram, blood pressure, body temperature, respiration and blood oxygen saturation, and the results are provided locally by the robot's processing system.
(2) Remote diagnosis and consultation
Through the robot's visual and auditory sensory functions, the collected video, audio and other data are combined with various physiological parameter data and transmitted to the remote medical center. Experts at the medical center conduct remote monitoring and, in conjunction with the medical expert system, conduct consultations on the health status of family members, that is, provide services of observation (video), auscultation, inquiry (audio), and palpation (various physiological parameters) [3].
3.1 Transmission of Robot Vision and Video Signals
The video signals collected by the robot serve two purposes: providing vision for the robot and transmitting the collected static and dynamic images of family members to a telemedicine center.
The role of robot vision is to obtain the necessary information from 3D environment images and construct a clear and meaningful description of the objects in the environment. Vision involves three processes:
(1) Image acquisition. The 3D environment image is converted into an electrical signal by a vision sensor (CCD CAMERA for stereo imaging).
(2) Image processing. Image-to-image transformations, such as feature extraction.
(3) Image understanding. Provide an environmental description based on the processed image.
Through video signal transmission, doctors at telemedicine centers can monitor the physical and mental states of family members in real time. Intelligent robots capture images suitable for healthcare and diagnostic needs, selectively transmitting high-resolution and low-resolution images. In the healthcare process, there are two different requirements for image transmission:
(1) When doctors observe the color of family members’ skin, lips, tongue, nails and facial expressions, they need to transmit static high-definition color images; the method used is to transmit one high-definition static image at intervals (e.g., 5 minutes).
(2) When doctors use dynamic images to check the physical mobility of family members, they can transmit images with lower resolution and smaller size. The method used is to perform reasonable compression and restoration to ensure real-time performance.
3.2 Robot Hearing and Audio Signal Transmission
The audio signals collected by the robot serve two purposes: first, they provide the robot with hearing; second, they allow family members to communicate with doctors, enabling doctors to understand the health status and mental state of family members. The transmission of audio signals provides doctors with a means of verbal communication to provide medical care to family members.
Robotic hearing is a form of speech recognition technology. Healthcare intelligent robots are equipped with various voice interaction systems, enabling them to perform medical tests and monitoring according to the commands of family members. They can also perform housework, control digital home appliances, and care for patients according to the commands of family members.
Multiple stereo microphones are used to acquire sound. Since the frequency range of sound is approximately 300Hz to 3400Hz, sounds with frequencies that are too high or too low generally do not need to be transmitted. Therefore, only sounds with a frequency range of 1000Hz to 3000Hz need to be transmitted for normal communication between doctors and family members. This reduces the bandwidth required for transmitting audio signals, and a suitable communication audio compression protocol can then be used to meet the requirements for real-time audio. The auditory system of the intelligent robot is shown in Figure 3.
3.3 Collection and Transmission of Various Physiological Information
Traditional diagnostic devices collect physiological information by connecting to the body via wires. The various wires can cause patient anxiety, leading to inaccurate data. Bluetooth technology effectively solves this problem. Miniature medical sensors with Bluetooth modules are placed on family members, minimizing interference with normal bodily activities. The collected data is then transmitted to a receiving device via Bluetooth for processing.
A detector with a Bluetooth module is installed on the intelligent robot as a receiving device. Various medical sensors transmit physiological information data collected to the detector via Bluetooth. The detector has two operating modes: one is to hand the data to the intelligent robot for processing and to provide local results; the other is to connect to the Internet (or send it back directly via a GSM wireless module) and transmit the data to a remote medical center via the network, achieving the purpose of medical care and remote monitoring. Video and audio data transmission also adopts this method. The data transmission system of the intelligent robot is shown in Figure 4.
4.1 Overview of Bluetooth Technology
Bluetooth technology [4] is a short-range wireless communication technology used to replace cables or wires. Its carrier uses the globally common 2.4GHz ISM band (the actual radio frequency channel is f=2402+k×1MHz, k=0,1,2,…,78), and uses frequency hopping to extend the band. The frequency hopping rate is 1600 hops/s. 79 channels with a bandwidth of 1MHz can be obtained. Bluetooth devices use GFSK modulation technology, with a communication rate of 1Mbit/s and an actual effective rate of up to 721Kbit/s. The communication distance is 10m and the transmission power is 1mW. When the transmission power is 100mW, the communication distance can reach 100m, which can meet the needs of digital homes.
4.2 Bluetooth Module
The ROKl01007 Bluetooth module [5] is a wireless baseband module launched by Ericsson suitable for short-range communication. It has high integration, low power consumption (RF power of 1mW), supports all Bluetooth protocols, and can be embedded in any device that requires Bluetooth functionality. The module includes five functional modules: baseband controller, wireless transceiver, flash memory, power management module, and clock, and can provide functions up to the HCI (Host Control Interface) layer. The structure of a single Bluetooth module is shown in Figure 5.
4.3 Hardware Composition of Master and Slave Devices
Bluetooth technology supports point-to-point PPP (Point-to-Point Protocol) and point-to-multipoint communication, and wirelessly connects several Bluetooth devices into a piconet [6]. Each piconet consists of one master device and several slave devices, with a maximum of 7 slave devices. The master device is responsible for the communication protocol. The MAC address is represented by 3 bits, that is, 8 devices can be addressed in one piconet (the number of interconnected devices is actually unlimited, but only 8 can be active at the same time, of which 1 is the master and 7 are slaves). Slave devices are controlled by the master device. All device units use the same frequency hopping sequence.
Miniature medical sensors with Bluetooth modules serve as slave devices, while detectors with Bluetooth modules on intelligent robots act as master devices. The hardware of both master and slave devices primarily includes antenna units, power amplifier modules, Bluetooth modules, embedded microprocessor systems, interface circuits, and some auxiliary circuits. The master device is the core of the entire Bluetooth network, responsible for converting between different communication protocols, sharing information, exchanging data with external communication networks, and managing and controlling all slave devices.
5. Conclusion
With social progress, economic development, and improved living standards, more and more people require home healthcare services. The intelligent robot system proposed in this paper, applied to digital home healthcare services, boasts comprehensive functions and has broad applications in areas such as home intelligent robots, Bluetooth-based smart homes, and digital hospitals, demonstrating significant market potential.
