Intelligent Control Systems for Physically Disabled and Elderly People for Indoor Navigation
The needs of many individuals with disabilities can be satisfied with traditional manual or powered wheelchairs, a segment of the disabled community finds it difficult or impossible to use wheelchairs. There is extensive research on computer controlled chairs where sensors and intelligent control algorithms have been used to minimize the level of human intervention. This paper describes a wheelchair for physically disabled people. This paper is to describe an intelligent powered wheelchair for handicapped person using voice signal, touch screen, ultrasonic and infrared sensor system which are interfaced with motors through microcontroller. When we want to change the direction, the touch screen sensor is modelled to direct the user to required destination using direction keys on the screen and that values are given to microcontroller. Depending on the direction selected on the touch screen, microcontroller controls the wheelchair directions. This can be controlled through the voice commands. The speech recognition system is easy to use programmable circuit that to be restored with the words which needs the circuit to be recognized. Possibility of avoiding obstacles by using ultrasonic sensors, downstairs or hole detection by using infrared sensors.
Intelligent robots are currently developed to help disabled and handicapped people at a high speed, and will be a certain key area in the next 10 years . Since the average age in our society is increasing notably in recent years, the number of people with severe motion impairments is increasing. The expenditure for healthcare and nursing is becoming a big burden for our society. On the other hand, the nursing staff is continuously reduced by the government and health authority in order to cut the cost. Therefore individual healthcare is becoming more expensive than before and people with medium and lower income are unable to afford such service. Driving a wheelchair in domestic environments is a difficult task even for a normal person and becomes even more difficult for people with arms or hands impairments .Fig.1 shows a model of a wheelchair. Some patients who cannot manipulate the direction of the wheelchair with their arms due to a lack of force face major problems such as orientation, mobility etc. Robotic wheelchair is developed to overcome the above problems. Robotic wheelchair extends the capabilities of traditional powered devices by introducing control and navigational intelligence. These devices can ease the lives of many disabled people, particularly those with sever impairments by increasing their range of mobility. This paper aims to resolve the above mentioned issue. In this paper we are going to make a wheelchair which can be controlled automatically as well as manually.
In this paper they made a wheelchair which can be controlled automatically as well as manually . This wheelchair controlled manually through head of the person sitting on it. He/she just need to move his/her hand into the direction it wants to move by using accelerometer. In automatic control user just need to press keys for saved destination. Then the wheelchair will move automatically move into the direction of saved destination by using encoder wheels. This chair also provide the another feature that is it can be operated by speech. The movement of powered wheelchair depends on the motor control and drive system which consists of microcontroller and motor driving. Once the voice recognition system recognizes voice commands in comparison to the stored memory, the respective coded signals would be sent to the microcontroller which then controls the wheelchair accordingly. Fig.2 shows the block diagram of control system in the wheelchair for navigation with voice recognition. This wheelchair controlled manually through hand of the person sitting on it. The speech is recognised by the HM2007 IC and processed thus giving commands to the microprocessor accordingly and hence to robot accelerometer moves his position thus gives analog signal to microcontroller and convert it to appropriate digital level so as to move the motors of wheelchair. It is the heart of the entire system. HM2007 is a voice recognition chip with on chip analog front end, voice analysis, recognition process and system control functions. The input voice command is analyzed, processed, recognized and then obtained at one of its output port which is then decoded, amplified and given to motors of robot. The chip provides the options of recognizing either forty 0.96 second words or twenty 1.92 second words. This circuit allows the user to choose either the 0.96 second word length or the 1.92 second word length. For memory the circuit uses 8K×8 static RAM. The chip has two operational modes manual mode and CPU mode. This is an attractive approach to speech recognition for computers because the speech recognition chip operates as a co processor to the main CPU.
Recent advancements in the technology are making lives easier for everybody. The system was successfully implemented to move the wheelchair left, right, forward, backward or stay in same position. This work is to help the disabled persons by providing alternative methods to control the equipment either by touch screen or through voice, there by serving many disabilities. Thus the wheelchair understands the signals coming from control system and reacts accordingly. The efficiency of the voice command control system can be further improved by implementing neural network based algorithms.
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