Users

Affordances

Interaction

Availability

Constraints

Social implications

Force Feedback Devices

CS147 technology evaluation by Yasuhisa Kato, email yasukato@stanford.edu, for Pomegranate (Anita) section.
This page is at
http://www.stanford.edu/~yasukato/class/cs147/as8.html

Introduction: What is force feedback devices?
We are talking about force feedback devices, which give us some feedback as a type of force during the interaction. There are many types of devices:  game pads, joysticks, gloves, steering wheels, trackball, mice, etc. One of famous and popular ones are game pads of SONY Playstation (Fig. 1) and NINTENDO 64 (Fig. 2). When playing some video games, these devices give users feedbacks as vibrations when users shot the gun or being hit by the enemy.

Fig. 1: Sony Playstation DUALSHOCK Analog Controller

Fig. 2: NINTENDO 64 Rumble Pack

And force feedback devices have a wide variety of target users from consumer use to research-oriented use. For example Fig. 3 shows a Microsoft force feedback joystick of $100, Fig. 4 shows a Immersion one of $4,000.

Fig. 3: Microsoft Force feedback Pro

Fig. 4: Immersion Impulse Engine 2000

These force feedback devices have been researched for many years. This research topic is called Haptics. There is a nice web page of the research community of Haptics.
Three years ago I visited CCRMA, Stanford University and Immersion Corporation, which is one of the leading companies in commercial haptics products. In CCRMA, the haptic user interface for blind persons was developed. It is called Moose, which haptically displays elements of graphical user Interfaces such as window edges, buttons, etc. In Immersion Corporation, I tried some devices and played haptical Ping-Pong and the former version of Impulse Engine.
In this evaluation article, we focus on consumer products and present their possibilities and difficulties.
 

Users: Games and Gamers
As I said the above , haptic devices of consumer use are so common these days, especially in video game market. The first video arcade game integrated with a haptic device was Hang-on developed by SEGA in 1985. (Fig. 5) It was a motorcycle riding game and users rode on the pseudo-motorcycle and got feedbacks from the physical position of the body, sound, and vibration. I played it so many times in Japan. So, these kinds of video arcade games have been developed over 15 years. These ideas and technologies have brought to home video games and haptic game pads have developed:  Playstation, NINTENDO, etc. Besides, PC-based devices have also developed over 10 years. PC-based devices are joysticks, steering wheels, and mice. Steering wheels are used only for driving games, and give us a great sense of realism: a sense of terrain, speed, and crash. Joysticks are multipurpose but good for flight simulator and tank battles. Mice are relatively new products, and suitable for every games, but we can feel buttons and menus in the web browser. It has some possibility of haptical web surfing.
 

Fig. 5: SEGA Hang-on (1985)
 
 

Affordances: Feedback
For example, when we play tank battle games, force feedback joysticks made it easy to do quick notice of the enemy and the terrain condition, and to give us full engagement to the application. When we play a flight simulator, for example, Microsoft Flight Simulator 2000. It is in the genre of the game, but it is different form other games. It has no gun shot, no scores, and no fighting. It is a real simulator. The force feedback joystick is very well suited for this game. The joy sitck can convey the status of the engine. The vibration of the Cessna is different from that of Concorde. It improves the affordances than using the normal joystick.
 

Interaction: Real-time
As for these force feedback game devices, real-time interaction styles are suited for these technologies. The metaphor is artificial mechanics. It is not a real one. When we play a driving game, we can use force feedback steering wheel and pedals. It is a simulator and give us a pseudo-real steering wheel. But not real one. As for the real car, car designers try to avoid the vibration of the steering wheel and we have no feedback from the steering wheel about the angle of the tires. This game is going to the different direction. Force feedback steering wheel enhances the vibration of engines and gives us some feedback of the angle of tires.

 

Availability: Playstation and Microsoft
Game pads of Playstation are most popular because of they are bundled to the players themselves. In PC market, Microsoft has 60% share of joysticks, it is not clear what percentage of them are force feedback. But it is obvious that Microsoft force feedback joysticks are also dominant in PC market. On the other hand, many company have products of force feedback joysticks, but key technologies are from Immersion Corporation. Force feedback technologies have licensed to more than twelve companies. Immersion Corporation calls the technology I-FORCE. And there are many products using I-FORCE. In this August, it was announced that  Microsoft and Immersion collaborated to advance feel simulation technologies. These two giants in force feedback market would like to make the de facto standards. It is a good news for application developers.
 

Constraints: Response time, cost, and portability
For example, Microsoft Force Feedback Pro gives us a good force feedback, but I feel a little frustration of response time. When I tried Impulse Engine at Immersion Corporation, the response time was very short and I felt as if I touched the real objects. It is a trade off between cost and performance. The better response micro motor is more expensive. And the cost is the key factor in consumer market. At this moment, the force feedback joystick is three four times higher than the normal one. The cost should be less than twice than the normal one, if the force feedback joystick would become a standard joystick.
Besides, the size of the joystick is relatively huge. We need a big space on our desk. We need a compact joystick with stronger force.

I have tried several applications. All of them are suited for force feedback joystick and the effectiveness of these types of feedback depends on the sensibility of users. For example, I tried driving game. The joystick simulated the vibration of the engine. As the speed increases, the vibration was getting bigger. It was very annoying during the concentration on the driving. Such a kind of feedback should be used by sound and vibration should be minimized. The design of force feedback applications are very important issues We have to identify what kind of force is applicable when. It is a highly application dependable issue.
 

Social implications: Beyond the game
Up to now commercially successful products of force feedback devices are only game devices. But there are a lot of research products for blind people. Fig. 6 shows one of the product for blind people to use PC Windows. Haptic devices have strong capabilities for disabilities to use PC and other computer-related systems. And a new product form Logitec (Fig. 7), WingMan Force Feedback Mouse, shows us some possibilities of enhancing mouse operation not only for games but also for general use. (Fig. 8 shows another product by Haptic technologies.) One of the promising implications is to use force feedback devices in the classroom. For example, in a class of physics student can virtually feel and experience the micro gravity of the moon while bouncing a ball with an elastic paddle using a force feedback joystick. (Fig. 9) Force feedback steering wheel and joysticks will become standards in game market, and Microsoft continues to be a top share of these products because of the alliance of Immersion Corporation. As for force feedback mice, I wonder it will replace all other mice. Force feedback mice should be remained to use in some special needs. But in the future, if very cheap and high performance micro motor and effective control mechanisms are developed and the size is as same as the standard mice, a force feedbck mouse will become a de facto standard in PC market.
 

Fig.6: Moose (CCRMA)

Fig. 7: WingMan Force Feedback Mouse (Logitech)

Fig. 8: MouseCAT (Haptic Technologies)

Fig. 9: Bouncing a ball

CS147 technology evaluation by Yasuhisa Kato, email yasukato@stanford.edu, for Pomegranate (Anita) section.
This page is at
http://www.stanford.edu/~yasukato/class/cs147/as8.html

[Force Feedback Devices]