Takahiro Wada

Takahiro Wada
Nara Institute of Science and Technology | NAIST · Graduate School of Information Science

Ph.D.

About

232
Publications
30,021
Reads
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1,492
Citations
Citations since 2017
72 Research Items
916 Citations
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
2017201820192020202120222023050100150200
Additional affiliations
April 2021 - present
Nara Institute of Science and Technology
Position
  • Professor (Full)
April 2012 - March 2021
Ritsumeikan University
Position
  • Professor (Full)
July 2006 - January 2007
University of Michigan
Position
  • Visiting scholar

Publications

Publications (232)
Conference Paper
Full-text available
Stair ascent is still a difficult task for transfemoral prosthesis users. So far, a passive knee joint unit for transfemoral prosthesis developed in our previous study achieved stair ascending without handrails or any other assistance devices. However, the experimental results with the simulated socket showed that the users faced difficulty in usin...
Article
Full-text available
We investigated the effect of the passenger head-tilt strategy on the severity of carsickness in lateral acceleration situations in automobiles. It is well known that the driver is generally less susceptible to carsickness than are the passengers. However, it is also known that the driver tilts his or her head toward the curve center when negotiati...
Preprint
Full-text available
Passengers of level 3-5 autonomous personal mobility vehicles (APMV) can perform non-driving tasks, such as reading books and smartphones, while driving. It has been pointed out that such activities may increase motion sickness, especially when frequently avoiding pedestrians or obstacles in shared spaces. Many studies have been conducted to build...
Article
Full-text available
In recent years, significant attention has been paid to remotely operated underwater vehicles (ROVs) in the performance of underwater tasks, such as the inspection and maintenance of the underwater infrastructure. The workload of ROV operators tends to be high, even for the skilled operators. Therefore, assistance methods for the operators are desi...
Preprint
Full-text available
【https://mobilityrxiv.sae.org/preprint/preprint--sae-pp-00303】Ride comfort improvement and motion sickness reduction are gaining attention given recent technological trends, such as the advancement of automated driving systems, the introduction of in-vehicle digital devices, and the daily use of mobile devices in vehicles. As a countermeasure, math...
Conference Paper
Without intervention the widespread adoption of autonomous vehicles could be compromised by an increased incidence of motion sickness compared to conventional cars. To investigate whether passengers’ motion sickness can be reduced by manipulating an autonomous vehicle's accelerations on a fixed route without altering the travel time, a human-out-of...
Article
Compact and economical remotely operated vehicles (ROVs) have become widely used worldwide. Nevertheless, it is not easy for inexperienced operators to control an ROV that moves while influenced by some external disturbance such as flowing water or waves. For this study, haptic shared control (HSC) was used to support beginner operators of an ROV i...
Conference Paper
Full-text available
【https://youtu.be/x1wsz54EOHs】【Opensource: https://github.com/lhl881210/Visual-Vertical-Estimation-for-6-DoF-SVC-Model】 【https://arxiv.org/abs/2202.06299】 Passengers (drivers) of level 3-5 autonomous personal mobility vehicles (APMV) and cars can perform non-driving tasks, such as reading books and smartphones, while driving. It has been pointed...
Conference Paper
Aiming to improve traffic safety, we investigated the effect of landscape and soundscape on driving behavior in urban roads using a VR driving simulator. While active and passive systems are implemented in vehicles and safer infrastructure is being proposed and built, previous research has suggested that the environment around roads also affects dr...
Article
Full-text available
With the development of virtual reality technology, head-mounted displays (HMDs) have been increasingly used to view or read 2D content while in vehicles. When 2D content is displayed in a fixed position on an HMD, the visual appearance does not change even with head movements, and body movements cannot be perceived while watching 2D content. This...
Article
Full-text available
There are concerns that viewing two-dimensional (2D) content such as web pages on a head-mounted display (HMD) in the car may aggravate motion sickness. This is because when 2D content is fixed to a head-fixed coordinate system, the appearance of the content does not change even when the body moves; therefore, it is impossible to visually perceive...
Preprint
Full-text available
Remotely operated vehicles (ROVs) have drawn much attention to underwater tasks, such as the inspection and maintenance of infrastructure. The workload of ROV operators tends to be high, even for the skilled ones. Therefore, assistance methods for the operators are desired. This study focuses on a task in which a human operator controls an underwat...
Article
As automated driving technology advances, drivers are gradually taking the role of passengers. During this transition of the driver’s role, learning methods to adapt the planned path to individual drivers have been proposed to improve the comfort and trust provided by automated driving systems (ADSs). However, existing methods apply offline learnin...
Article
Full-text available
For heterogeneous traffic with weak lane discipline (2D mixed traffic), a quantitative investigation of the arrangement of vehicle types is necessary to understand and accurately simulate traffic phenomena. This study accordingly directly detected the vehicle groups observed frequently in 2D mixed traffic footage collected in Mumbai, India to inves...
Article
Full-text available
Recently, various visual information presentation systems known as human–machine interfaces (HMIs), such as road projection lamp systems, have been developed for safe driving. However, it is unclear how these HMIs change the drivers’ gaze behavior and improve their cognitive awareness of the environment. Therefore, in this study, we introduce the c...
Article
Full-text available
Drivers occasionally need to resume vehicle control when an automated driving system (ADS) cannot handle a situation. However, a lack of driver readiness can prevent a smooth transition. For example, in an obstacle avoidance situation, a method to transfer the vehicle control based on the driver’s input of the steering angle can be adopted where ra...
Article
Full-text available
Dental hygienist students require a self-learning simulator to learn the correctness of hand-scaling techniques. An essential technique in hand scaling is the maintenance of contact between the tip of the hand-scaler blade and the tooth. However, imaging-based methods cannot effectively reveal this contact because the gingiva and buccal mucosa conc...
Conference Paper
Full-text available
We proposed a method for generating the head posture of a vehicle occupant that minimizes the incidence of motion sickness by using a mathematical model of motion sickness. Numerical simulation using the proposed method demonstrated that the predicted motion sickness was significantly smaller with the optimized head motion than the condition in whi...
Preprint
For assembly tasks, it is essential to firmly fix target parts and to accurately estimate their poses. Several rigid jigs for individual parts are frequently used in assembly factories to achieve precise and time-efficient product assembly. However, providing customized jigs is time-consuming. In this study, to address the lack of versatility in th...
Conference Paper
For heterogeneous traffic with weak lane discipline (2D mixed traffic), a quantitative investigation of the arrangement of vehicle types is necessary to understand and accurately simulate traffic phenomena. This study accordingly directly detected the vehicle groups observed frequently in 2D mixed traffic footage collected in Mumbai, India to inves...
Article
Full-text available
Understanding the relationship between driving behavior and visual information is important for holistic understanding of driving behavior. However, the analysis of the cognitive behavior for steering/throttle control has been only conducted under a special simulator environment. Therefore, in this study, we aimed to develop a convolutional neural...
Article
As deep learning methods in image recognition have achieved excellent performance, researchers have begun to apply CNNs(convolutional neural networks) to automated driving. However, the explainability for the decision making of automated driving is highly desired. In order to trust the model in automated driving, visualization methods have become i...
Article
Full-text available
The existing computational models used to estimate motion sickness are incapable of describing the fact that the predictability of motion patterns affects motion sickness. Therefore, the present study proposes a computational model to describe the effect of the predictability of dynamics or the pattern of motion stimuli on motion sickness. In the p...
Article
We quantitatively clarified that, in an actual mixed traffic, the distributions of the types of leaders and followers for each vehicle type have biases toward the distributions predicted based on the number of each type of vehicle. Vehicular traffic in some countries is heterogeneous, having weak lane-discipline, i.e., 2D mixed traffic. Previous st...
Article
Drivers’ gaze behaviors in naturalistic and simulated driving tasks have been investigated for decades. Many studies focus on driving environment to explain a driver’s gaze. However, if there is a great need to use compensatory steering for lane-keeping, drivers could preferentially acquire information directly required for the task. Therefore, we...
Article
The vestibulo-ocular reflex (VOR) is the reflexive eye movement occurring in the opposite direction of head movement to stabilize the visual image during head movement. We hypothesize that there exists a correlation between motion sickness and the accuracy of VOR because motion sickness and VOR are thought to be related to the head movement signals...
Preprint
The existing computational models used to estimate motion sickness are incapable of describing the fact that the predictability of motion patterns affects motion sickness. Therefore, the present study proposes a computational model to describe the effect of the predictability of dynamics or the pattern of motion stimuli on motion sickness. In the p...
Chapter
In this study, we focus on the effects of the lateral shift of leading vehicles (leaders) and the steering operation of following vehicles (followers) on the response time and deceleration of the followers. A physical investigation on heterogeneous traffic with weak lane discipline is required because of heavy congestion in certain developing count...
Article
Under certain scenarios, an automated driving system (ADS) might need to transfer steering control to the human driver. Even if the driver is ready to take over, an abrupt control transition when traversing a curve can lead to unstable steering. This is because the steering wheel is balanced by both the self-aligning torque and ADS torque; if the l...
Article
Recently, with the active development of automated driving systems (ADSs) corresponding to SAE automated driving level 2, the comfort of ADSs has gained significant attention. In our previous research, it was proposed that the comfort of ADSs is affected by their maneuvers and the degree of information sharing between ADS and drivers. However, even...
Article
Merging behavior requires multiple tasks such as cognition, decision-making, and driving operation. Previously, driving assistance systems, which instruct drivers on making accelerations, have been studied to support the decision-making task. The importance of improving driver comfort with adjusting system variables has been revealed through these...
Conference Paper
The purpose of this study was to develop a prosthetic knee joint unit suitable for pedaling by modeling pedaling using four-link mechanisms and examining the link length and joint torque that maximizes crank torque. As a result, the crank torque increased as the link length became shorter. The joint torque of the simulation switched the function of...
Conference Paper
Operation of remotely operated underwater robot (ROUV) is known to be difficult due to limited sensor information from the robot. We proposed to apply ta haptic shared control (HSC) approach, in which a human operator and an automation interact congruently in a perception-action cycle to perform a dynamic task by force inputs of both agents to a si...
Conference Paper
To regain the locomotive ability in daily living, many prosthetic knee joint units have been developed for transfemoral amputees. Until now, several prosthetic knees have been developed for stair ascent as commercial products, such as Genium® (Otto Bock, GmbH). Such microprocessor controlled knees are multifunctional, and they are able to realize m...
Article
The development of Advanced Driver Assistance Systems (ADAS) for fully automating the operation of automobiles is rapidly progressing. However, challenges related to driving skill improvement of drivers exist because of the necessity of manual operation, and these are expected to continue in the future. Despite the fact that maintaining and improvi...
Article
This paper discusses the robustness of the performance of the closed loop system for a homogeneous finite time proportional-derivative control (FT-PD control) of a one-link robot manipulator. We show that FT-PD control's disturbance rejection performance of low frequency is superior to the conventional PD control via the describing functions estima...
Article
Full-text available
Advanced driver-assistance systems have successfully reduced drivers’ workloads and increased safety. On the other hand, the excessive use of such systems can impede the development of driving skills. However, there exist collaborative driver-assistance systems, including shared and cooperative controls, which can promote effective collaboration be...
Conference Paper
Full-text available
In controlling an authority transfer from automated driving to manual driving, there is a danger that an abrupt transition of steering control can cause disruptions to the handling. Furthermore, while paying attention to the run of the curve, the control transition becomes complicated. This is because the torque by the automated driving system is m...
Conference Paper
Full-text available
While automated driving systems (ADSs), which correspond to level-two automated driving of Society of Automotive Engineers (SAE), are being developed actively, the ADS that learns the preference of drivers at an opportune time is required. In addition, there is a lack of assessments on ADS comfort. In this study, we focused on collision avoidance a...
Conference Paper
Full-text available
Objective and quantitative evaluation of ride comfort can be achieved owing to recent advances in cybernetic models. Therefore, we developed a mathematical model for analyzing motion sickness and utilized it to evaluate comfort in vehicle riding. It is known that the inclination of the head toward the gravito-inertial force (GIF) decreases the seve...
Conference Paper
Full-text available
In automated driving, there are certain situations in which the user and automated system must interact. For example, at the SAE J 3016 (2016) LoDA 3 level of driving automation, a human operator is expected to intervene in the operations of an automated driving system (ADS) in response to an intervention request issued by the ADS. Haptic shared co...
Conference Paper
The vestibulo-ocular reflex (VOR), which is a reflexive eye movement generated in the direction opposite to that of the head movement, is affected by mental workload(MWL). A computational model to estimate the VOR from head movement has been proposed. Previous research has shown that when humans perform mental tasks, the error between the measured...
Preprint
Full-text available
Advanced driver assistance systems have successfully reduced drivers' workloads and increased safety. On the other hand, the excessive use of such systems can impede the development of driving skills. However, there exist collaborative driver assistance systems, including shared and cooperative controls, which can promote effective collaboration be...
Article
Full-text available
Merging into the flow of high-speed traffic on roadways, such as expressways, is a demanding driving task for non-expert drivers. The difficulty of merging is thought to arise from the difficulty of judging the location where the drivers should merge. In this paper, we propose a mathematical model of driver decision-making that can predict the loca...
Article
We have built a mathematical model for motion sickness disease and have utilizedit to evaluate comfort in vehicle riding. It is known that the inclination of the head toward gravito-inertial force (GIF) decreases the severity of motion sickness, this research focuses on the motion sickness incidence (MSI) as an evaluation index of ride comfort. Thu...
Article
The vestibulo-ocular reflex (VOR), which is a reflexive eye movement generated in the direction opposite to that of the head movement, is affected by mental workload(MWL). A computational model to estimate the VOR from head movement has been proposed. Previous research has shown that when humans perform mental tasks, the error between the measured...
Article
In automated driving, there are certain situations in which the user and automated system must interact. For example, at the SAE J 3016 (2016) LoDA 3 level of driving automation, a human operator is expected to intervene in the operations of an automated driving system (ADS) in response to an intervention request issued by the ADS. Haptic shared co...
Conference Paper
We have currently been developing passive mechanism for multifunctional prosthetic knee joint unit that is an important part of transfemoral prosthesis. The passive mechanism for prosthetic knee that we previously developed allowed users to walk on the ground and ascend stairs. In the present study, a joint which rotation (knee flexion) was control...
Conference Paper
Full-text available
The vestibulo-ocular reflex (VOR), which is a reflexive eye movement generated in the opposite direction of head movement, is affected by volition of the head movement; it indicates the activeness or passiveness of the head movement. Research has yet to reveal the effect of actively operating or passively riding on a vehicle on a human's VOR. There...
Article
Full-text available
Although automation-initiated and driver-initiated control transfers from automated to manual driving may yield unstable steering activity even when the drivers are focused on the road environment ahead, there are few studies on the development of control transfer methods at an operational level after a request to intervene (RTI). Therefore, we pro...
Article
Full-text available
It is known that car drivers tilt their head toward the center of a curve. In addition, drivers are generally less susceptible to carsickness than are the passengers. This paper uses a mathematical model to investigate the effect of the head-tilt strategy on motion sickness. It is shown that tilting the head in the centripetal direction reduces the...
Article
Full-text available
Previous research has shown that the effective use of inertial motion (i.e., less or no torque input at the knee joint) plays an important role in achieving a smooth gait of transfemoral prostheses in the swing phase. In our previous research, a method for generating a timed knee trajectory close to able-bodied individuals, which leads to sufficien...
Conference Paper
In this research, we propose a method to connect automated and manual driving by haptic shared control (HSC) to achieve shared authority mode and authority transfer method in this mode. Driving simulator experiments showed that the smoother steering behaviors were observed with the proposed method even when rapid steering was required just after ta...
Conference Paper
Full-text available
Smooth authority transfer from automated to manual driving is an important problem for highly automated vehicles. In automation-initiated authority transfer, many studies have approached the timing for a request to intervene in order to guarantee an appropriate reaction of the human driver. However, few studies have investigated authority transfer...
Article
Full-text available
Self-driving systems are expected to become increasingly popular in the foreseeable future. However, a driver who is out of the control loop might reduce overall situation awareness by overly trusting automated driving systems. Alternatively, the introduction of automated driving systems could lead to misuse or disuse. For these reasons, an automat...
Article
Advanced driver assistance systems (ADASs) have successfully reduced drivers’ workload and increased safety. However, the excessive use of such assistance systems might reduce the chances of developing drivers’ skill. Haptic-shared and cooperative controls are methods in which the automated system shares a single operation with human operators and...
Conference Paper
A wide variety of robot tasks cannot be achieved by a smooth velocity field. This paper considers discontinuous desired velocity fields that represent robot tasks. We propose passivity velocity field control (PVFC) with discontinuous desired velocity fields. The method deals with a discontinuous field produced by a generalized differential of a non...
Article
Advanced driver assistance systems (ADASs) have been developed and have subsequently decreased opportunities for driver skill development because of degraded situational awareness and less activity in the control loop. Beginning drivers must therefore engage in training. The idea has arisen that haptic shared control, which encourages a driver to o...