Have you ever played a video racing game where the controller vibrates to warn you when you veer off track? If so, you've already grasped the sensory implications of haptic interfaces. The word "haptology" comes from the Greek word *haptikos*, meaning to grasp or perceive. Through haptic robots, users can sense distant or virtual environments. Haptic interfaces provide users with realistic tactile feedback, allowing them to feel things they don't directly touch. For example, a haptic interface lets you feel the resistance of a simulated flight steering wheel, and the haptic feedback helps the pilot know how much force to apply. One of the cutting-edge areas of haptic research is called "passive haptics." Traditional haptic interfaces are active, meaning the system uses motors and wind power to increase the perceived force on the user. The risk of active haptic systems is that the power source might add excessive force, potentially harming the user. Passive haptic interfaces are designed with safety options, using passive power sources such as magnetorheological brakes to eliminate the force rather than adding it. Passive haptic interfaces are not only safer but also more energy-efficient. Researchers at the Intelligent Machines Dynamics Laboratory (IMDL) at the Georgia Institute of Technology are investigating the applications of passive haptic systems. Dr. Wayne Book and graduate student Benjamin Black are conducting research to observe whether, with additional safety measures, passive haptic systems can perform as effectively as active haptic systems in remote device operation. A major limitation of passive haptic systems is that the devices cannot be fixed in one place. Furthermore, unlike active haptic systems, passively powered devices must guide the operator to the desired location. Dr. Book and Black are attempting to develop advanced passively powered device control schemes to overcome this difficulty. Using Graphical System Design Methodologies Graphical system design methods break down system design into several steps. Graphical system design introduces graphical development software tools and off-the-shelf hardware to accelerate the design, prototyping, and configuration of embedded control devices. The researchers used the National Instruments LabVIEW graphical software development platform to design and simulate the haptic control system and remote operation communication. The designed product is then configured into a real-time PXI control and data acquisition system to test the solution. The advantage of this testing method is that Dr. Book and Black can avoid spending time on low-end embedded software development and customized hardware design when configuring products, and instead devote themselves entirely to iterative experimentation and design. Researchers can quickly input their master-slave controller algorithms into LabVIEW, and then load the power devices and sensors using a high-level programming interface. By loading the algorithms with actual hardware, they can verify the correctness of the theory with real data. Figure 1 shows the graphical source code of the researchers operating the slave controller position. In addition, the software tools provide advanced acquisition interfaces, such as timed-loop functionality. A timed-loop is a LabVIEW programming structure that can acquire priority and multi-threaded detail data. Through these different types of acquisition methods, engineers and scientists can easily apply multi-threading functionality to their software. This gives researchers more time to refine their product designs instead of spending time on low-end code development. Hardware Design Configuration Researchers configure software algorithms for PXI module hardware systems. These systems include deterministic, real-time controllers and appropriate I/O modules for touch-sensitive sensor devices. Using LabVIEW Real-Time Modules, researchers can configure their algorithms onto a PXI controller for headless operation. They employ a plug-and-play motion control module to handle the linear slave motor and a multi-functional data acquisition device to handle the fixed-point sensor. The test instrumentation for this study uses a two-degree-of-freedom (DOF) manipulator as the master to control a one-degree-of-freedom (DOF) linear motor as the slave. There is no physical connection between the master and slave; instead, the PIX Real-Time Control System is connected to the master, and another system is connected to the slave, as shown in Figure 2. PIX System 1 uses a deterministic application on NI LabVIEW to read data from the gamma sensor and the optical encoder on the master manipulator. Researchers use this data to determine the master's position and transmit it to PXI System 2. PXI System 2 uses the master's position as a fixed point to output a signal to a 4kHz PD (proportional-derivative) controller designed in LabVIEW to run the linear motor while simultaneously reading the position data from the optical encoder. The slave device's movement is constrained by its physical structure. The location of the slave device is transmitted back to the master device via UDP to the PXI system 1, where the data is loaded into the control algorithm that determines the haptic force to be applied to the user, allowing them to perceive the presence of physical constraints. This force is driven by a magnetorheological actuator. The system's purpose is to allow the slave device's location to track the master device's location. Dr. Book and Black are now conducting simulations and in-depth research using LabVIEW-based dynamic systems. Using system identification technology, researchers can build a dynamic digital simulation structure between the master and slave devices using real-world data collected in simulations and feedback experiments. They used result inequalities combined with the LabVIEW simulation module to calculate real-time formulas simulating the feedback between different control laws. This simulation process helps them to more quickly and repeatedly validate the laws before applying them to the production of haptic devices. Summary This research story once again demonstrates how current technological advantages pave the way for future technologies. By employing a graphical system design approach, Dr. Book and Black leveraged the democratization of embedded development to achieve groundbreaking research. Mr. Gerardo Garcia is a Product Marketing Manager at National Instruments, specializing in real-time measurement and control modules. He graduated from Texas A&M University with a Bachelor of Science degree in Electrical Engineering Design.