Characteristics of Mobile Robotic Toys for Children withPervasive Developmental Disorders *

François Michaud1, Audrey Duquette2, Isabelle Nadeau1

1Department of Electrical Engineering & Computer EngineeringUniversité de Sherbrooke

Sherbrooke, Québec (Canada)Francois.Michaud@USherbrooke.ca

2Department of Psycho-EducationUniversité de Sherbrooke

Sherbrooke, Québec (Canada)

* 0-7803-7952-7/03/$17.00 ” 2003 IEEE.

Abstract – Pervasive developmental disorders (PDD)refers to a group of disorders characterized by delays inthe development of multiple basic functions includingsocialization and communication. Symptoms may includecommunication problems such as using andunderstanding language; difficulty relating to people,objects, and events; unusual play with toys and otherobjects; difficulty with changes in routine or familiarsurroundings, and repetitive body movements or behaviorpatterns [1]. Autism is the most characteristic and beststudied PDD. We are investigating the use of mobilerobotic toys that can move in the environment and interactin various manners (vocal messages, music, visual cues,movement, etc.) with children with autism. The hypothesisis that mobile robots can serve as an appropriatepedagogical tool to help children with PDD developsocial skills because they are more predictable and lessintimidating. The objective is to see how such devices canbe used to capture the child’s attention and contribute tohelping him or her develop social skills. This paperoutlines the design considerations for such robots, andpresents experimental protocols that are being developedto study the impacts of using these robots on thedevelopment of the child.

Keywords: Mobile robot, pervasive developmentaldisorders, autism.

1 IntroductionChildren with pervasive developmental disorders

(like autism) are characterized by severe and pervasiveimpairment in social interaction skills, communicationskills and the presence of stereotyped behavior, interests,and activities. Children with PDD vary widely inabilities, intelligence, and behaviors: some do not speakat all, others speak in limited phrases or conversations,and some have relatively normal language development[1]. Repetitive play skills and limited social skills aregenerally evident [1]. Unusual responses to sensoryinformation like loud noises and lights are also common[1]. A lot remains to be discovered about the causes andthe cure of autism, and care and therapeutic approaches canhelp people with autism maximize their potential, eventhough impairments in social and communication skillsmay persist throughout life. One of the challenges is tofind appropriate pedagogical tools that can catch the

child’s attention and generate interest in learning todevelop social and communication skills.

A solution with a lot of potential is to use robotictoys that can interact in interesting ways, creating novel,appealing and meaningful interplay situations usingspeech, sounds, visual cues and movement. The robot canask the child to imitate its movements. Mobile robotictoys are colorful and small, which make them lessintimidating than an adult. Robotic toys also have theadvantage that they can be programmed to responddifferently to situations and events. A robot can follow adeterministic play routine but they can act according tothe unexpected situations experienced in the environmentor caused while interacting with a child. A robot can alsolearn over time and change the ways it responds to theworld, generating more sophisticated interactions andunpredictable situations that can help capture and retainthe child's interest. This flexibility allows robotic toys toevolve from simple machines to systems that demonstratemore complex behavior patterns. In our case, theinteraction framework created by our robots is to get theattention of the child, asks the child to do something, andto reward the child if the request is successfully satisfied.

For five years now we have been experimenting withmany different kinds of mobile robotic toys. Since eachchild has his or her own personality, interests andcapabilities, it was important to see how children react torobots of different shapes, sizes and functionalities. Thispaper reports experiments done with children with autismand other learning disabilities. The mobile robots havebeen used in experiments ranging from single sessions ofa couple of minutes to consecutive use over a five weeksperiod. The objective at this stage is to outline whatworks and what does not work in trying to find incentivesfor the child to make the effort of opening up to his or hersurroundings. In this paper we present the specificationsthat we have learned to be the most appropriate fordesigning such robots, and the experimental protocols thatare being developed to study the impacts of using theserobots on the development of the child.

2 Previous experimentsUsing interactive robotic toys as part of the

educational program is surely an interesting idea that hasthe potential of providing an additional interventionmethod to the rehabilitation process of autistic children.The AURORA project (AUtonomous RObotic platform asa Remedial tool for children with Autism) [3,4,5,12] isone of such initiatives. Just to cite the general aspects ofthis project, AURORA investigates how an autonomousmobile robot can be develop into a remedial tool in orderto encourage children to become engaged in a variety ofdifferent interactions that possess features which areimportant elements of human social behavior (eye-contact,joint attention, approach, avoidance, following, turn-taking, imitation games, etc.) [4]. A non-humanoid robotis used, based on the observation that autistic childrenprefer predictable, stable environments, and that they havedifficulty interpreting facial expressions and other socialcues. The robot used in their experiments is a Labo-1mobile platform, with a rectangular body and four wheels,eight infrared proximity sensors, and a positional heatsensor. The idea is to use the robot to bridge the gapbetween the variety and unpredictability of human socialbehavior and the predictability of repetitive andmonotonous behavior so appreciated by children withautism and that can be reproduced continuously by mobilerobots. Experiments with the Robota doll [2] was alsodone as part of the AURORA project. Robota is anintelligent robotic doll that can communicate by movingand by perceiving contact on different parts of its body,imitate the arm and head movements of a user, and learnsentences to describe its actions, combination ofmovements and simple dance patterns.

Since 1998 we at the Department of ElectricalEngineering and Computer Engineering of the Universitéde Sherbrooke have been designing a great variety ofmobile robotic toys with the goal of using them aspedagogical tools for children suffering from autism orother developmental disorders. Since each child is adistinct individual with preferences and capabilities, itmight not be possible to design one complete robotic toythat can help capture and retain the interest of every child.So our strategy is to design many different types ofrobots, and observe the possible factors that mightinfluence the child's interests in interacting with a robotictoy, like shape, colors, sounds, music, voice, movements,dancing, trajectory, special devices, etc., and learningfrom our observations to design new robots that could inthe near future be used by parents and educators. Thesedesigns are made as part of a design project at theundergraduate level in the Electrical Engineering andComputer Engineering curricula [9,10,11]. Experimentsusing promising designs are conducted by LABORIUS,the research laboratory on mobile robotics and intelligentsystems of the Université de Sherbrooke.

Two types of experiments have been conducted withautistic children: short sessions at the École du Touret,and using robots over a couple of weeks period with

groups of children at the S.P.E.C. Tintamarre Summercamps.

2.1 Short sessions

These sessions were held in two rooms and in threedifferent occasions: in a regular classroom, and in a 20' by20' room without tables and chair. In some sessions therobots were presented one by one to each child, while inothers the robots were working simultaneously andchildren were brought in and out by the educators.Children were allowed to interact freely with the robots.At all time at least one educator was there to introduce therobot to children, or to intervene in case of trouble. Eachsession lasted around one hour and a half, allowing eightto ten children to play with the robots. No specialattention was put on trial length for each child, since ourgoal was to let all the children of the class play with therobots in the allocated time slot. Here is a summary ofobservations made with some of robots, shown in Figure1, used in these trials [5].

Jumbo Roball

CPAC Bobus

Diskcat Maestro

Figure 1. Examples of mobile robotic toys.

• Jumbo is an elephant has a moving head and trunk,one pyroelectric sensor and an infrared range sensor.Jumbo is programmed to move toward the child andto stop at a distance of 20 cm. Once close to thechild, Jumbo asks the child to touch one of the threebuttons associated with pictograms located on itsback. LEDs are used at first to help the child locatethe right pictogram, but eventually the LEDs are notused. If the child is successful, Jumbo raises itstrunk and plays some music (Baby's Elephant Walkor Asterix the Gaulish). If the child is notresponding, the robot asks to play and can try toreposition itself in front of the child. Pictograms onthe robot can be easily replaced. This robot revealedto be very robust, even though its pyroelectric lensesgot damaged too. One child liked to push the robotaround when it was not moving, or to make the robotstay close to her if it was moving away. Thepictogram game was also very nice, but children werepressing on the pictograms instead of on the buttons.The music played and movements of the trunk werealso very appreciated by the children.

• Roball [7] is a spherical robot capable of navigatingin all kind of environments without getting stucksomewhere or falling on the side. Interactions can bedone using vocal messages and movement patternslike spinning, shaking or pushing. The majority ofchildren were trying to catch Roball, to grab it or totouch the robot. Some even made it spin (but notalways when requested by Roball though). One boy,who did not interact much with almost all of theother robots presented, went by himself in order toplay with Roball. One of the games he played was tomake the robot roll on the floor between his arms,and eventually let it go forward by itself.

• C-Pac is a very robust robot that has removable armsand tail. These removable parts use connectors thathave different geometrical shape (star, triangle,hexagon). When successfully assembled, the robotthanks the child and rotates on itself. The robot alsoasks the child to make it dance by pressing its head.The head then becomes illuminated, and music (LaBamba) is played as the robot dances, and this wasvery much appreciated by children. C-Pac also has amoving mouth, eyes made of LEDs, an infrared rangesensor and pyroelectric sensors to stay close to thechild. Children learned rapidly how to play with thisrobot, even understanding by themselves how toassemble the robot. The removable parts became toyson their own. Children were also surprised whenthey grabbed the robot by its arms or tail, expectingto grab the robot but instead removing the part fromthe robot. Note however that the pyroelectric lensesgot damaged by the children, and one even took offthe plastic cup covering one eye of the robot and triedto ate it.

• Extremely robust, Bobus can detect the presence of achild using pyroelectric sensors. It then slowly moves

closer to the child, and when close enough it doessimple movements and plays music. Simple requests(like touching) are made to the child and if the childresponds at the appropriate time, light effects aregenerated using the LEDs all around the `neck' of therobot, and the small ventilator on its head isactivated. Very robust, this robot is the only one withpyroelectric senses that did not got damaged. Twolittle girls really liked the robot, enjoying the lighteffects, the moving head with the ventilator, and thedifferent textures. At one point, one girl lifted therobot and was making it roll on its side on top of herlegs. She then put the robot on the floor and wasmaking it roll on its side using her legs again, but bylying on top of the robot.

As expected, each child had his or her own ways ofinteracting with the robots. Some remained seated on thefloor, looking at the robot and touching it when it cameclose to them (if the robot move to a certain distance,some children just stop looking at the robot). Othersmoved around, approaching and touching the robots andsometime showing signs of excitation. In general, we didnot observed particular attention to the front of the robots,mostly because most of them have devices all aroundthem. Even though these children were not capable offluent speech, some were able to understand the shortmessages generated by the robots. It is very hard togeneralize the results of these experiments since each childis so different. In addition, the mood of some of thechildren that participated to all of these sessions was notalways the same. But one thing that we can say is that therobots surely caught the attention of the children, makingthem smile, laugh or react vocally.

One very interesting observation was made withanother robot (Diskcat) and one little girl of about 10years of age. This robot has a special fur exterior andlooks like a cat. Games like ‘Simon says’, dancing andvisual effects using LEDs as eyes and on the back of therobot have been implemented. Resistive bend sensors areused as whiskers. When she usually enters the recreationroom, she starts right away to follow the walls, and shecan do this over and over again, continuously. Figure 2shows the trajectory she did with the robot in the room.The robot was near a wall, not moving (region A). Thelittle girl started to follow the walls of the room, andinteracted with the robot for short amount of times, at therequest of the educator as she went by the robot.Eventually, the robot moved away from the walls (regionB) and she slowly started to stop, first at one particularcorner of the room (region 1), and then at a second place(region 2) for looking at the robot moving around. At onepoint when the robot got to a corner of the room (regionC), she took the robot by its tale and dragged it back tothe center of the room where she believed the robot shouldbe. She even smiled and made eye contact with some ofus, something that she did not do with strangers. Thisshowed clear indications that having the robot moved inthe environment helped her gradually open up to hersurroundings.

A

B

C

12

Figure 2. Overhead view of the trajectory done by a girlwith DiskCat in the room.

2.2 Trials at S.P.E.C. Tintamarre Summer Camps

Three sets of experiments were conducted over theyears. In a first set of trials, Jumbo was used one day aweek over a period of five weeks, for 30 to 40 minutes infour different groups. Children and young adults weregrouped according to the severity of their conditions, theirautonomy and their age. Four to ten people were presentin each group, along with two or three educators, and eachgroup had its own room. Children were placed in a circle,sitting down on the floor or on small cubes depending ontheir physical capabilities. The robot always remained onthe floor, and each child played in turns with thepictograms. Once a turn was completed, a new set ofpictograms was used.

With the groups that did not have physicaldisabilities, children manifested their interests as soon asJumbo entered the room, either by looking at the robot orby going to touch it, to push it, to grab the trunk or bypressing on the pictograms. The music and the dance werevery much appreciated by the children. The amount ofinteractions varied greatly from one child to another.Some remained seated on the floor and played when therobot was close to them. Others either cleared the way infront of the robot, or moved away from its path when itwas coming in their direction. The amount of time theyremained concentrated on the robot was longer than for theother activities they did as a group. One little girl whodid not like animals, had no trouble petting Jumbo. Shewas also playing in place of others when they took toomuch time responding to a request or did mistakes. Oneboy did the same thing (even by going through the circle),and he was very expressive (by lifting his arms in the air)when he succeeded with the pictograms.

To the group of teenagers, Jumbo is real. Theytalked to the robot, reacted when it was not behavingcorrectly or when it was not moving toward them. Someeducators were also playing along because they weretalking to Jumbo as if it was a real animal, by calling itsname, asking it to come closer. When Jumbo did notrespond correctly and was moving away, educators wouldsay something like ``Jumbo! You should clean your ears!''or “Jumbo has big ears but cannot hear a thing!'”. Oneboy showed real progress in his participation, hismotivation and his interactions because of the robot. Hisfirst reaction was to observe the robot from a distance, buthe rapidly started to participate. His interest toward therobot was greater than the other kids. He remembered thepictograms and the interactions they had with the robotfrom one week to another. He also understood how tochange the pictograms and asked frequently the educatorsto let him do it. Another boy also liked to take Jumbo inhis arms, like an animal. He showed improvements inshape and color recognition.

In the second set of trials, children came one by oneto play with a robot in a classroom where Diskcat and areal dog were. The first observation made was that it isimportant to let the child become familiar with the roomso that his or her attention is not drawn to other things inthe room. The same familiarization phase by the child isrequired to get to know the robot or the dog. Somechildren were more interested to play with the robot,others with the dog. Having an educator encourage whatthe child is doing correctly with the robot or the dog,letting him or her take the time to interact correctly towhat happens and showing them that they can succeedhave very positive impacts on the child. Children alsoknow that the dog is real and the robot is not a livingentity. However, the dog eventually get tired when thechild does not interact appropriately, but not the robot.

The third set of trials was done in a room with onlythe robot, Maestro, in the middle. Before entering theroom, we showed a pictogram of the robot to the child.Maestro is programmed to move around in theenvironment, goes toward the child and interact using anilluminated keyboard. Different musical games are offered,and when the child succeed the puppet smiles andvibrates, and the robot dances. We let the child play withrobot 15 minutes at a time, observe what was happeningfrom a distance but intervene whenever necessary. Theseobservations led us to the elaboration of the list ofconsiderations for the design of mobile robotic toys forchildren with autism, presented in Section 3.

3 Considerations for the design ofmobile robotic toysOur experiments revealed that autistic children are

interested by the movements made by the robots, andenjoy interacting with these devices. Robustness of the

robots is surely of great importance, as some of the morefragile designs got damaged, but mostly by the samechild. Having removable parts is good as long as they arebig enough: all small components or material that can beeasily removed should be avoided. Having the robotsbehave in particular ways (like dancing, playing music,etc.) when the child responds correctly to requests madeby the robot becomes an incentive for the child tocontinue playing with the robots. The idea is to createrewarding games that can be easily understood (because ofits simplicity or because it exploit other skills develop inother activities like the use of pictograms or geometricalshapes) by the child.

First, the robotic toy should take into considerationthe following characteristics associated with children withautism:

• Deficits in visual sense. The physical appearance ofthe robot should by itself be a good incentive forcatching the child’s attention. Nice colors, roundshapes, lights, objects that rotate, or mechanical parts(many children get very curious with how the robotworks). Avoid too bright colors, sharp edges, ropes.

• Deficits in auditory sense. Children like intriguingsounds, music, songs. Do not make very high or lowpitch sounds or very loud noise. Sounds must beused to catch the attention of the child withoutscaring him or her.

• Deficits in touching. Soft, robust, safe and washablesurfaces should be used to make the external structureof the robot. Removable parts are also veryappreciated by children. Children like to explore,manipulate and put things in their mouth. Everythingthat should not be touched by children should beadequately hidden.

• Deficits in spatial perception. Children with autismhave difficulties noticing what is particular and whatis common in an environment. They might be moreinterested by the walls than by an object placed in themiddle of a room. That is why the robot should, byits motion, its sounds and its appearance, be designedto capture as much as possible the attention of thechild.

• Deficits in language. Visual elements like images andphotos are more appropriate that just use words. Thevocabulary used by the robot must be very simple,messages should be short (three words or less) andrepeated frequently. Words should refer to concretethings rather than abstract notions.

• Deficits in symbolic games. Games with the robotshould be simple and easy to understand. Childrenwith autism do not play like regular children. Sharingand imitation are something that they do not

naturally do. The robot should be designed to helpchildren develop such skills.

• Particularities of each child. Since each child is anindividual with distinct interests and capabilities, therobot should offer different set of games andcapabilities that can evolve over time and be adaptedto the child. The robot should encourage andcongratulate the child when he or she is doing well,but must not critic incorrect response to requestsmade.

4 On-going workWith all of the experiments done so far

demonstrating the potential interests and characteristics ofusing mobile robotic toys with children with autism, weare now designing a mobile robot specifically to conductexperiments that will evaluate the scientific impacts onchildren and not just the engineering aspects.

The robot will be approximately 60 cm tall. It willuse wheels to move, but its structure will show two feetand two legs. It will also have two articulated arms thatwill be able to move up or down, a head that can rotate(to say no) and rise up (to surprise the child), a mouth (forsmiling), a nose, two eyes and hair (made with fiber opticcable to illuminate them). It will be possible to illuminateeach part of its body. The robot will be read, blue andyellow. The robot will be capable of autonomous motion(avoiding obstacles) and it will be possible to teleoperatethe robot using a RF remote control. A series of vocalmessages will be able to be generated by the robot. Therobot will also be able to sense if it is being shaken or ifit has flipped over. The activation button will be hiddenon the back of the robot. The robot must be simpleenough so that it can be operated by non-robotic experts.

The objectives of these new sets of experiments areto see if a mobile robot can make the child imitate it, andif the robot can help the child learn his or her differentbody parts. The hypothesis is that if the child can imitatethe robot, the child gets interested not only in objects ingeneral but also in something that is similar to humans inits mobility and some of its skills. Also, we assume thatbody representation can be developed from the perceptionof others, the communication with others and theimitation of others.

Fives game scenarios are going to be experimented,with the robot being teleoperated. Each child will play forabout 10 minutes with the robot, three times per week.Each scenario will be experimented over two weekperiods. At the end of each of these scenarios the robotwill leave the room by saying: “Robot done”, “Door”,“Bye bye”. All of the experiments are going to berecorded and analyzed using five evaluation forms. Thechildren will have approximately four years old with theability to understand simple sentences and words. Four

children will be selected for the experiments, using thediagnostic tool ADOS-G [6].

The first is to get familiarized with the robot. Tobegin, the robot starts by telling the child it status whilemoving in the room and having one arm rising up: “Merobot”, “Me happy” (and smile), “Me walking”. The robotis going to point different objects in the room andidentify these objects. The second scenario is to identifypersons that the child knows. A photo of these persons aregoing to be placed on a wall, and the robot will point thephotos and ask the child questions like: “Where Mom?”,“Where you?”, etc. The third scenario aims at theidentification of the child’s body parts. The robot willilluminate one of its parts and say which part it is. Thenthe robot will ask the child to do the same. The fourthscenario is an imitation game. The robot will ask thechild to do the same things it is doing (like movingforward, backward, turning, etc.). In these last threegames, when the child succeeds, the robot will smile andraise its arms. If the child fails, the robot will just say“no” and shake its head. The fifth scenario is a hide-and-seek game. These trials are going to take place in the Fall2003.

5 ConclusionEngineers need to combine their expertise with

scientists in the field of autism, in order to get interestinginsights that will help guide the design of innovative newrobots. The application describes in this paper is only oneexample of such rich source of multidisciplinary research.Our hope is that mobile robotic toys can become efficienttherapeutic tools that will help children with autismdevelop early on the necessary skills they need tocompensate for and cope with their disability.

AcknowledgmentFrançois Michaud holds the Canada Research Chair

(CRC) in Mobile Robotics and Autonomous IntelligentSystems. This research is supported financially by theCRC Program, the Canadian Foundation for Innovation(CFI) and the Fonds Québécois de la Recherche sur laNature et les Technologies (FQRNT) of Québec. Theauthors also want to thank the teams of students involvedin the design of the robots used for these experiments, andmore specifically those who went to test their robots withautistic children.

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