ASIMO

Dev Bahadur Poudel

May 2, 2012

1 IntroductionASIMO is the state of the art humanoid robot in the world. ASIMO stands for “Advance Step in Inno-vative Mobility”.ASIMO was developed by Honda Motor Co. Ltd, a Japanese Corporation.[1] It wasnamed with reference to an American professor and science fiction writer Issac Asimov who was creditedfor proposing Three Laws of Robotics. ASIMO was officially unveiled on 2000 after fifteen years ofresearch.The purpose to build ASIMO is to build a robot that can help human being and live in harmonywith people.

2 Features/AbilitiesASIMO has weight of 48kg and height 1.3 m. ASIMO has the ability to walk and run. It has the walkingspeed of 2.7km/hr and running speed of 9km/hr.[1] It is capable of running backward and continuouslyjumping up and down.It is also capable to interact with the gestures and human being postures of .ASIMOcan perform task according to the gesture of human being.For example it can recognize an indicatedlocation and move to that location.It shakes the hand when hand is given.Another example of gesturerecognition is when a person waves hand it also waves its hand.

It can recognize faces of person and also distinguish the person. It can recognize people by theirfaces and by their voices. It can address people by their name.It can distinguish between voices and othersounds. It turn to face the speaker when its name is called. It also recognize sudden, unusual soundslike falling of object and collision. It has ability to recognize obstacles and avoid the obstacles duringthe movement. It is able to assess its immediate environment and recognize the position of obstaclesand avoid them to prevent collision.ASIMO has ability to interact with human significantly. It can greetapproaching people , follow them, move in the direction they indicate.It has internet connectivity and canprovide information to people. Hence ASIMO is the world’s first most intelligent humanoid robot.

ASIMO can maintain balance while walking on uneven surfaces and slopes. It can also maintainbalance when pushed or impacted to a certain degree. It falls down when pushed strongly. It cannot getback on its feet by itself.

Joints DOFs TotalHead Neck Joint(up/down,Left/Right,Rotation) 3 DOFArm Shoulder joints(forward/backward, up/down,Rotation 3 DOF

Elbow joints(forward/backward) 1DOFWrist joints(up/down,left/right,rotation) 3 DOF 2 arms*7 DOFs=14

Hands 4 fingers/thumb 2 DOF 2 hands* 2 DOFs=4Hips Rotation 1 DOF 1Legs Crotch joint(forward/backward, left/right, rotation) 3 DOF

Knee joints(forward/backward) 1 DOFAnkle joint(forward/backward, left/right) 2 DOF 2 legs*6 DOFs=12

Total 34

3 Basic Design Policy/MechanismJoints/Degrees of Freedoms

ASIMO has head ,hands and legs which movements are similar to human beings. Joint angle sensorsare used to determine the angle and position of the body. Force and torque sensors are used in ASIMOto find force and torque of each motors.There are gyro sensors to measure the orientation of ASIMO.Thedegrees of freedom in each joint is as shown in the table.

Latest ASIMO has 57 degrees of freedom.Compliance Control

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Landing impact force is absorbed by the rubber brushes inserted in the feet of the robot. The rubberdeforms elastically in the vertical direction which prevents vibration of leg and accomplish control ofcompliance[3].

Posture BalanceThe position of the body is control using Zero Moment Point Control Mechanism. ASIMO bends its

legs to maintain a stable movement pattern based on ZMP trajectories.[3]MovementASIMO uses i-Walk technology[2] ,a predicted movement control.It can predict its next movement

in real time and shift its center of gravity in anticipated direction. The body posture is balanced duringwalking using Desired Zero Moment Point Control[3]. The bipedal movement of ASIMO is based onfunctions involving dynamic walking based on sensory feedback and predictive movement planning.When ASIMO walks, it predicts an ideal movement path consisting of Zero Moment Points and tilts itsbody sideways or forward to shift its center of gravity in anticipation. Real-time predictive movement-planning enables ASIMO to make minor adjustments to its movement trajectory.

Technology/IntelligenceASIMO is controlled by a laptop or a portable computer controller unit through wireless network

system.ASIMO has a three-dimensional computer processor that was created by Honda and consists ofprocessors, a signal converter and memory. The computer that controls ASIMO’s movement is housed inthe robot’s waist area and can be controlled by a PC, wireless controller, or voice commands. ASIMOcan comprehend and carry out tasks based on simple voice commands given in English that have beenpre-programmed into its on board memory. ASIMO has several sensors to acquire the raw data from theenvironment. It has gyro sensors to sense the orientation, force sensors to obtain the forces, microphonesto detect the sound and cameras for vision to obtain image pixels.ASIMO also has a camera mounted inits torso[1] used to view markers on the floor and on stairs.

ASIMO’s vision system is responsible for processing spatial perception, object-mapping, humantracking, facial recognition, and gestural-postural detection. It relies on stereo images (of two viewsfrom slightly different angles) provided by the frame grabber that is connected to the two color boardcameras on the head unit of the robot. 3D and moving objects are identified by calculating depth of spacebased on the Sum of Absolute values of Differences (SAD) method using the images that are captured inblack-and-white and calibrated for lens distortion. A local map of 3D objects is constructed and providedto the agent programs for walking and movement. The vision system also identifies moving parts of themoving objects, from which the recognition of human gestures and postures is processed and provided tothe agent programs for human-robot interaction and eye control.[4]

ASIMO can identify multiple people in a scene by using the snake algorithm to distinguish the con-tours of human shapes. When in motion, ASIMO tracks humans by using an optical flow-based algorithmto lock on their changing positions in the image data. 2D gesture recognition algorithm can identify hand-shake, hand-circling, farewell, hand swing, high hand, and come here-call based on the probabilities fora given position of the hand using the Bayes statistical model. 3D gesture recognition algorithm canidentify where a person is pointing at based on the relative positions of the person’s head and hand fromthe depth map data. Face is recognized by applying the eigen vector Method on the face contour and eyeimage data.[4]

ASIMO relies on the sound data to be situationally aware of the surrounding outside its field of vision.The sound’s direction is calculated based on the volume and time differences of the signals at two separatemicrophones. It can discern human voices and footsteps from the sound data and look when a person callsits name, or something falls on the floor.

ASIMO uses sonar, infrared sensor and rangefinder to detect the obstacles. It makes an in memorylocal map[4] using vision. It reconstruct a map after obstacle detection and move to the point of interestin autonomous manner.

4 Criticism /LimitationsWhen ASIMO falls down by aggressive external forces then it cannot stand up at its own.ASIMO istargeted to mimic human beings however it lack some senses of human. It has vision and auditorycapabilities but does not have capabilities like smelling and feeling . It has no emotional capability forhappiness and disgusting expressions.

Robots are build with purpose to work in hazardous environment but ASIMO does not have suchcapability. ASIMO is used as receptionist in an office. This means that implementation of large number ofASIMOs in various sectors of office can increase the unemployment rate of human. ASIMOs are not usedin Military missions. They cannot be used in underwater environment and other risky environment wherehuman cannot work.Honda is seeking to develop a robot based on the ASIMO to handle the radiationleakage at the Fukushima nuclear power plant that resulted with the earthquake and tsunami that hitJapan in March, 2011.

They are also not designed in weightless environment like outer space.

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References[1] ASIMO http://asimo.honda.com/downloads/pdf/honda-asimo-robot-fact-sheet.pdf. Technical report.

[2] ASIMO Technical Information 2007 http://asimo.honda.com/downloads/pdf/asimo-technical-information.pdf. Technical report.

[3] K. Hirai, M. Hirose, Y. Haikawa, and T. Takenaka. The development of honda humanoid robot. InRobotics and Automation, 1998. Proceedings. 1998 IEEE International Conference on, volume 2,pages 1321–1326 vol.2, 1998. ID: 1.

[4] Y. Sakagami, R. Watanabe, C. Aoyama, S. Matsunaga, N. Higaki, and K. Fujimura. The intelli-gent asimo: system overview and integration. In Intelligent Robots and Systems, 2002. IEEE/RSJInternational Conference on, volume 3, pages 2478–2483 vol.3, 2002. ID: 1.

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