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Reviewer: D. Charles Hair

The problem of providing touch and force feedback (both referred to as “haptic feedback”) in virtual reality systems is explored in this book. The author notes that haptic feedback is generally necessary for a robust virtual reality setting, but that much progress is needed in this area. In addition to discussing the problems involved, the book reviews the progress that has been made and discusses current work in the field. The first chapter gives an introduction to the field that includes definitions of terms as well as a brief history of developments in the area dating back to telerobotics work done in the 1950s and 1960s. Chapter 2, “Haptic Sensing and Control,” describes relevant human sensing characteristics. This information is then used extensively in discussing the merits of current technologies for employing haptic feedback in virtual settings. Chapter 3 concerns actuators that provide feedback to users. It describes and compares the different capabilities of electrical, hydraulic, and pneumatic actuators. The author explains how these three different types of actuators operate. The discussion is tied to descriptions of actuators that are currently available commercially. The fourth chapter is titled “Nonportable Force Feedback.” Force feedback involves mechanisms for giving haptic feedback to computer users. These mechanisms can be classified according to location, meaning whether the hardware is grounded to the desk, floor, wall, or possibly the user's back. They can also be differentiated according to whether or not they are portable. Nonportable systems are more common, but portable systems are the subject of more current research. The desk-based devices reviewed include joysticks, pen-based devices, stringed devices, and a sensing glove. The floor and ceiling devices include arm devices, personal motion platforms, and exoskeletons. The main drawback of these fixed devices is the restriction on the user's range of motion. The main advantage is that the user is not burdened with the weight of the device. The fifth chapter reviews portable force feedback devices. These are classified as either exoskeletons or hand devices, both of which are reviewed. Chapter 6, “Tactile Feedback Interfaces,” draws the distinction between force feedback interfaces and tactile feedback interfaces, such being that tactile feedback is used to augment feedback data about surface geometry or mechanical texture. These devices can be simpler and lighter, and they can function as standalone interfaces or in combination with force feedback systems. The chapter describes a variety of approaches. Chapter 7 concerns the physical modeling needed to generate input to haptic interfaces. The emphasis here is on using real-time computer input to cause virtual objects to behave according to real-world physical laws. The idea is to use the laws of physics to allow such actions as grasping virtual objects, but to disallow things like having the user's virtual hand pass through an object. Various techniques are reviewed in this chapter. Chapter 8 discusses control of haptic surfaces, reviewing control methodology, quality of feedback, distributed computing, and virtual reality programming with haptic feedback. Chapter 9 concerns human factors, specifically, the effects of the introduction of haptic feedback into virtual reality systems. The discussion includes possible drawbacks, including “simulation sickness” and other possible safety issues. Chapter 10 reviews some of the more promising domains for employing haptic feedback in virtual reality systems. The areas looked at are medicine, entertainment, telerobotics, and the military. The final chapter takes a short look at the future. The author foresees major improvements, particularly in making haptic devices less cumbersome, safer, and more capable of supporting a wide range of motion. This is a current book on an interesting area of virtual reality. It is well written and does a good job of covering haptic feedback. It also includes a comprehensive list of references, along with a list of companies and research laboratories involved in the field (including phone numbers and email addresses). This is an excellent text for anyone with a serious interest in the area and could be used in an advanced course in virtual reality.