# Teleolocation--Remotely Operated Legged Robots
## 6 Conclusions  
This paper introduces and implements telelocomotion, or real-time remotely operated walking robots. While autonomous locomotion may suffice in well known terrains, it relies on assumptions such as predictable contact mechanics. Humans on the other hand are well adept at responding to unanticipated scenarios. Combining the maneuverability of legged robots with the high-level decision making of humans can allow robots to negotiate challenging terrain. Offline approaches, as shown in the DRC, can be used to plan footholds but do not achieve desirable robustness in overall gait execution. This exploratory work proposed a haptic-enabled telelocomotion interface. The proof-of-concept method mapped user input configuration to amplitude and reach of the hexapod gait. Haptic feedback in the form of a spatial virtual fixture encouraged users to remain within a 2D spatial plane, and periodic circular motion resulted in effective forward and backward motion. The method was validated with two different user studies. The first examined three different online telelocomotion interfaces--keyboard (**K**), gaming controller (**J**), and the haptic-enabled telelocomotion interface (**H**) with different simulated traversal difficulties. Despite the simple nature of interface **H**, results show comparable performance to modes **K** and **J** on flat surfaces, and significantly better performance on stairs. Figure 13 and Table 2 depict these results. Modes **K** and **J** show high degrees of degradation moving from the flat maze to the staired environment, while performance deviated far less using **H**. In the second study, the method was adapted to a physical implementation of the hexapedal robot. Users were tasked with navigating a real, physical, staired obstacle course using the interface with either haptic virtual fixtures disabled (**D**) or enabled (**E**). Results are promising and demonstrate that the planar virtual fixtures indeed reduced time to completion and steps required to complete the real-world telelocomotion task on average. While results are still preliminary, bean and box-whisker plots show that typical performance is more tightly grouped and consistent about the average in both metrics when the haptic virtual fixtures were enabled. Removing outliers strengthens this observation and enhances the observed improvements when using the haptic enabled mode, **E**, as compared to **D**. Figure 14 and Table 3 depict these preliminary results. The maximum traversal speed with ideal conditions of the PhantomX hexapod is about 80 cm/s [61]. With stairs and ramps, the speed to traverse the 4.5m course here is about seven times slower than experiments without obstacles [62]. In this work, 3 DOF haptic devices were used to telelocomote an 18 DOF hexapod by constraining hexapod motion via fixed joint angles and the holistic motion for an alternating tripod gait. With a simple mapping, low dimension user inputs translated to high-level telelocomotion of a high dimensional legged robot. Future work will look more closely at designing efficient mappings from low dimensional inputs to operating kinematically dissimilar devices, and precise foot placements should be analyzed via Denavit-Hartenberg parameters. This is particularly crucial for navigating more complex terrains; in this work no modifications to the gait or footholds were made to account for stairs. The ideal interface may depend on the degree of kinematic dissimilarity and types of sensory data. More extensive studies can also be conducted to further evaluate performance gains along a more granular scale of terrain traversal complexity, as well as investigating varying mapping gains \(\alpha_{x},\alpha_{y}\) (in this study, these were heuristically tuned to 10 and nine respectively)to affect different parameters, such as speed, stride length etc.. Disaster situations can present challenging terrains unsuited for predetermined traversal strategies, and different modes of control or levels of autonomy may be best suited for each task or environment.