While driving a vehicle, perceiving velocity is important for appropriate operation and is one of the most important factors for preventing collisions and traffic congestion. In contexts where perceiving velocity changes is difficult, such as on an undulating road, the velocity may exceed the speed limit or traffic congestion may occur due to heavy braking to avoid a collision. Hence, we proposed a method of modulating the perception of velocity through tactile stimulation to promote adequate operation for the driver. In contrast to methods using visual and auditory stimulation, this method has advantages of not increasing the visual cognitive load, not disturbing the enjoyment of music, and reliably stimulating the driver. In this study, we constructed a velocity perception model based on vibrotactile stimulation induced by the engine speed and proposed a method of changing the vibrotactile stimulation by altering the shift position of the transmission to modulate the perception of velocity without additional vibration actuators, regardless of the actual velocity. We measured the seat and engine vibration using two different vehicles. The results demonstrated that the peak acceleration frequencies are proportional to engine speed, indicating that the vibration depends upon the engine speed, not the velocity. We implemented a method of changing the shift position in an actual vehicle and verified the feasibility of the method through a psychophysical experiment. The results showed that drivers perceived a higher velocity with increasing engine speed and lower velocity with decreasing engine speed.

1. [1] M. Koshi, M. Kuwahara, and H. Akahane, “Capacity of sags and tunnels on japanese motorways,” ITE J., pp. 17-22, 1992.
2. [2] Y. Mori, M. Kurihara, A. Hayama, and S. Ohkuma, “A study to improve the safety of expressways by desirable combinations of geometric alignments,” Proc. of 1st Int. Symp. on Highway Geometric Design Practices, 1995.
3. [3] A. Kitaoka, “Slope illusion (magnetic hill) in radan,” Art and Its Role in the History: Between Durability and Transient, pp. 751-760, 2015.
4. [4] C. Blakemore and F. W. Campbell, “On the existence of neurones in the human visual system selectively sensitive to the orientation and size of retinal images,” J. of Physiology, Vol.203, No.1, pp. 237-260, doi: 10.1113/jphysiol.1969.sp008862, 1969.
5. [5] M. A. Winnett and A. H. Wheeler, “Vehicle-activated signs – a large scale evaluation,” TRL Report, TRL548, 2002.
6. [6] W. H. Warren and D. J. Hannon, “Direction of self-motion is perceived from optical flow,” Nature, Vol.336, Issue 6195, pp. 162-163, doi: 10.1038/336162a0, 1988.
7. [7] W. H. Warren, “Chapter 8 – Self-motion: visual perception and visual control,” W. Epstein and S. Rogers (Eds.), “Perception of space and motion,” Academic Press, pp. 263-325, doi: 10.1016/B978-012240530-3/50010-9, 1995.
8. [8] A. Han, S. Ono, K. Ikeuchi, Y. Suda, and M. Sasaki, “Road marking ‘optical dot system’ for controlling the speed – development and four years empirical analysis,” 20th ITS World Congress ITS Japan, 2013.
9. [9] A. Han, S. Ono, K. Ikeuchi, Y. Suda, and M. Sasaki, “Optical dot system’ as assistance for drivers to visualize affordance of road environment,” Seisan Kenkyu, Vol.66, Issue 2, pp. 147-154, doi: 10.11188/seisankenkyu.66.147, 2014.
10. [10] S. Shinoda, M. Hashiba, and H. Hoshina, “Melody road and melody road design,” Japan, JP4708354, 2011.
11. [11] M. Yoshino, K. Noda, and H. Ogino, “Evaluation of musical pavement in Kawade-cho, Toyota,” Toyota National College of Technology, Vol.41, pp. 95-100, 2008 (in Japanese).
12. [12] N. Merat and H. Jamson, “A driving simulator study to examine the role of vehicle acoustics on drivers’ speed perception,” 2011 Driving Assessment Conf., doi: 10.17077/driving assessment.1401, 2011.
13. [13] T. Seno, M. Ogawa, H. Ito, and S. Sunaga, “Consistent air flow to the face facilitates vection,” Perception, Vol.40, No.10, pp. 1237-1240, doi: 10.1068/p7055, 2011.
14. [14] B. E. Riecke, A. Väljiamäe, and J. Schulte-Pelkum, “Moving sounds enhance the visually – induced self – motion illusion (circular vection) in virtual reality,” ACM Trans. on Applied Perception, Vol.6, No.2, pp. 1-27, doi: 10.1145/1498700.1498701, 2009.
15. [15] M. Tachiiri, Y. Tanaka, and A. Sano, “Vibrotactile Stimulation to Change Velocity Perception in Automobiles,” SICE J. of Control, Measurement, and System Integration, Vol.10, Issue 3, pp. 177-183, doi: 10.9746/jcmsi.10.177, 2017.
16. [16] A. Telpaz, B. Rhindress, I. Zelman, and O. Tsimhoni, “Haptic seat for automated driving: preparing the driver to take control effectively,” Proc. of the 7th Int. Conf. on Automotive User Interfaces and Interactive Vehicular Applications, pp. 23-30, doi: 10.1145/2799250.2799267, 2015.
17. [17] Y. Kurihara, T. Hachisu, M. Sato, S. Fukushima, and H. Kajimoto, “Periodic tactile feedback for accelerator pedal control,” 2013 World Haptics Conf., pp. 187-192, doi: 10.1109/WHC.2013.6548406, 2013.
18. [18] T. Mizuno, H. Asano, and H. Ide, “Evaluation of Cognition of Information Which is Stimulated by the Sense of Touch Using Phantom Sensation and Apparent Movement,” J. Robot. Mechatron., Vol.21, No.1, pp. 87-94, 2009.
19. [19] A. Israr, H. Z. Tan, and C. M. Reed, “Frequency and amplitude discrimination along the kinesthetic-cutaneous continuum in the presence of masking stimuli,” The J. of the Acoustical Society of America, Vol.120, Issue 5, pp. 2789-2800, doi: 10.1121/1.2354022, 2006.
20. [20] J. Romano and K. J. Kuchenbecker, “Creating realistic virtual textures from contact acceleration data,” IEEE Trans. on Haptics, Vol.5, No.2, pp. 109-119, doi: 10.1109/TOH.2011.38, 2011.
21. [21] K. Ida, “Mechanism of vibration and noise reduction,” The Society of Rubber Science and Technology Japan, Vol.64, No.2, pp. 62-75, 1991 (in Japanese).