Manual Steering Research Articles

Heart Rate Variability in Response to Task Automation in Agricultural Semi-Autonomous Vehicles

The goal of this study was to assess the sensitivity of the heart rate variability measure to variations in task difficulty and drivers' mental workload in agricultural semi-autonomous vehicles. 30 young participants with at least one year of tractor driving experience performed steering and implement control and monitoring tasks in a simulator study. Experiments were conducted using the tractor driving simulator (TDS) located in the Agricultural Ergonomics Laboratory at the University of Manitoba. Five levels of automation support from low to high were defined for the implement control and monitoring task. One-half of the participants performed a manual steering task while the other half drove the TDS in automatic steering mode, which only required them to monitor a mapping system and supervise the computer that was performing the steering task. A heart rate monitor was used to record the participants' heart rate. Time and frequency domain parameters of heart rate were analyzed. Some of the time and frequency domain parameters showed some sensitivity to workload variations, however, inconsistencies were observed in the results. The widely used HRV parameter, 0.1 Hz component of HRV, was not sensitive enough to differentiate mental workload levels when the drivers were involved in the task-loop.

RTK GPS and Automatic Steeringfor Peanut Digging

<abstract><title><italic>Abstract. </italic></title> Peanut harvesting is a two-stage process. In the first stage, a digger-shaker-inverter implement is used to plow peanut from the ground. In the second stage, a combine is used to thresh peanut pods from the vines. Yield loss can be significant, especially during the digging stage where the implement may not be properly aligned over the rows of peanut. In this study, RTK-based automatic steering was compared to manual steering to determine the potential for reduced yield losses. In addition, peanut response to the plant growth regulator prohexadione calcium was compared to a non-treated peanut to determine if reduced yield losses were obtainable. Prohexadione calcium regulator did not improve yield significantly. However, use of RTK based automatic steering was significant, increasing harvested yield by 510Â kg/ha or 11%.

Design and Realization of Tracking Autopilot for Leisure Yacht

On the basis of the autopilot control principle and the STM32F103RBT6 controller, an tracking autopilot for the leisure yacht was designed with manual steering and automatic steering function in this paper. The schematic circuit design and software design were detailedly described. Practical application confirmed that the autopilot has high reliability and good steering performance.

Effect of Using GPS Autosteer Guidance Systems on the Eye-Glance Behavior and Posture of Tractor Operators

Tractor operators are prone to neck and back discomfort and disorders. It is well known that awkward posture is a major contributor to this problem. Previous studies have investigated the prevalence of awkward posture and the resulting discomfort and disorders among tractor operators. They have also suggested various ways to mitigate this problem. With the introduction of new autosteer guidance systems, the tractor operator is relieved from the task of steering the tractor for most of the time during field work. Therefore, it is expected that the operator's posture will change. The goal of this study was to investigate the changes in the eye-glance behavior and posture of tractor operators as a result of using autosteer guidance systems. An eye-tracking system and a camcorder were used to record the eye-glance behavior and posture of 13 tractor operators as they performed seeding operations. The experiment with each operator consisted of two sessions. In one session, the operator used an autosteer system, while in the other session the operator steered the tractor manually. Analysis of the data showed that the eye-glance behavior and posture of the operators were significantly different between the autosteer and manual steering sessions. With the autosteer system, the operators spent less time in an awkward posture, and they changed their posture less frequently. However, even with the autosteer system, the operators spent 1/3 of their time in an awkward posture. Subjective feedback from the operators indicated that more than half of them experienced back or neck/shoulder discomfort during or after seeding. It is essential that the recommendations of the previous studies, such as using large rear-view mirrors or a rotating tractor seat, be evaluated when the operator is using an autosteer system. Other tools, such as video cameras that show the attached equipment, should also be tested to evaluate their effectiveness in reducing the operator's exposure to awkward postures.

Effective rotations: Action effects determine the interplay of mental and manual rotations.

The last decades have seen a growing interest in the impact of action on perception and other concurrent cognitive processes. One particularly interesting example is that manual rotation actions facilitate mental rotations in the same direction. The present study extends this research in two fundamental ways. First, Experiment 1 demonstrates that not only manual rotations facilitate mental rotations but that mental rotations also facilitate subsequent manual rotations. Second, Experiments 2 and 3 targeted the mechanisms underlying this interplay. Here, manual steering wheel rotations produced salient visual effects, namely the rotation of either a plane or a horizon in an aviation display. The rotation direction of these visual effects either did or did not correspond to the direction of the manual rotation itself. These experiments clearly demonstrate an impact of sensory action effects: Mental rotations facilitate manual rotations with visual effects of the same direction (as the mental rotation), irrespective of the direction of the manual rotation. These findings highlight the importance of effect anticipation in action planning. As such they support the contentions of ideomotor theory and shed new light on the cognitive source of the interplay between visual imagery and motor control.

Evaluation of an auto-guidance system operating on a sugar cane harvester

Precision farming tools such as auto-guidance systems assembled on tractors and/or sugar cane harvester machines are being applied to decrease the costs involved with ethanol production. The purpose of this study was to evaluate the accuracy, the cane loss and the operational field efficiency achieved by an auto-guidance system used to guide a sugar cane harvester over the field when compared to a manually-guided machine. The field test was conducted with two treatments: auto-guidance versus manual guidance; and day versus night. Each treatment was replicated four times. Each position recorded represented a single sample, which was used to calculate the error between the planned and actual paths. It was concluded that the use of an auto-guidance system operating on a sugar cane harvester during the day and night periods increased the field pass-to-pass accuracy relative to the planned row track, but it is essential that the crop was planted using the system. The use of the auto-guidance system did not significantly decrease the sugar cane loss, once the crop was well cultivated. More long-term research needs to be done related to this issue. The operational field efficiency of the cane harvester was the same for both auto-guidance and manual steering systems.

Steering a tractor by means of an EMG-based human-machine interface.

An electromiographic (EMG)-based human-machine interface (HMI) is a communication pathway between a human and a machine that operates by means of the acquisition and processing of EMG signals. This article explores the use of EMG-based HMIs in the steering of farm tractors. An EPOC, a low-cost human-computer interface (HCI) from the Emotiv Company, was employed. This device, by means of 14 saline sensors, measures and processes EMG and electroencephalographic (EEG) signals from the scalp of the driver. In our tests, the HMI took into account only the detection of four trained muscular events on the driver’s scalp: eyes looking to the right and jaw opened, eyes looking to the right and jaw closed, eyes looking to the left and jaw opened, and eyes looking to the left and jaw closed. The EMG-based HMI guidance was compared with manual guidance and with autonomous GPS guidance. A driver tested these three guidance systems along three different trajectories: a straight line, a step, and a circumference. The accuracy of the EMG-based HMI guidance was lower than the accuracy obtained by manual guidance, which was lower in turn than the accuracy obtained by the autonomous GPS guidance; the computed standard deviations of error to the desired trajectory in the straight line were 16 cm, 9 cm, and 4 cm, respectively. Since the standard deviation between the manual guidance and the EMG-based HMI guidance differed only 7 cm, and this difference is not relevant in agricultural steering, it can be concluded that it is possible to steer a tractor by an EMG-based HMI with almost the same accuracy as with manual steering.

Avaliação da acurácia no direcionamento com piloto automático e contraste da capacidade de campo operacional no plantio mecanizado da cana-de-açúcar

Com o crescimento da mecanização da cana-de-açúcar, é necessária uma dinamização dos processos, como no uso de técnicas de agricultura de precisão para uma diminuição do custo de produção. O presente trabalho foi desenvolvido com o objetivo de contrastar a acurácia nas passadas orientadas por dois sistemas de direcionamento, autodirecionamento via satélite versus manual, assim como comparar as capacidades de campo e a eficiência operacional envolvidos no plantio mecanizado da cana-de-açúcar. Foram analisados dois tratamentos: com e sem o auxílio do piloto automático por GPS RTK na operação de plantio mecanizado. As avaliações foram realizadas em condições de campo, na Usina IACO Agrícola S.A., em Chapadão do Sul - MS. De acordo com os resultados obtidos, afirmou-se que o uso do piloto automático na operação de plantio da cana-de-açúcar ofereceu uma acurácia de 0,033 m entre as passadas, sendo cinco vezes maior do que aquela obtida com o direcionamento manual, e que o seu uso não melhorou a eficiência operacional do conjunto mecanizado na operação de plantio, sendo limitada pelo sistema de colheita e transporte da cana muda para a plantadora.

Robotic versus manual control in magnetic steering of an endoscopic capsule

Capsular endoscopy holds promise for the improved inspection of the gastrointestinal tract. However, this technique is limited by a lack of controlled capsule locomotion. Magnetic steering has been proposed by the main worldwide suppliers of commercial capsular endoscopes and by several research groups. The present study evaluates and discusses how robotics may improve diagnostic outcomes compared with manual magnetic steering of an endoscopic capsule. An endoscopic capsule prototype incorporating permanent magnets was deployed in an ex vivo colon segment. An operator controlled the external driving magnet manually or with robotic assistance. The capsule was maneuvered through the colon, visualizing and contacting targets installed on the colon wall. Procedure completion time and number of targets reached were collected for each trial to quantitatively compare manual versus robotic magnetic steering ( T-test analysis with P = 0.01). Then, through a set of in vivo animal trials, the efficacy of both approaches was qualitatively assessed. In ex vivo conditions, robotic-assisted control was superior to manual control in terms of targets reached (87 % +/- 13 % vs 37 % +/- 14 %). Manual steering demonstrated faster trial completion time (201 +/- 24 seconds vs 423 +/- 48 seconds). Under in vivo conditions, the robotic approach confirmed higher precision of movement and better reliability compared with manual control. Robotic control for magnetic steering of a capsular endoscope was demonstrated to be more precise and reliable than manual operation. Validation of the proposed robotic system paves the way for automation of capsular endoscopy and advanced endoscopic techniques.

유량 및 부하가 변하는 상태에서의 양로드 유압실린더의 위치제어시스템

A double-end rod hydraulic cylinder is widely used with a steering valve for the steering control system in large tractors. For the development of automatic steering controller, the feasibility of using a proportional control valve replacing the conventional manual steering valve to control the position of hydraulic steering cylinder was investigated in terms of the max. overshoot, the steady-state error and the rise time. A simulation model for the electrohydraulic steering system with load using AMESim package was developed to be valid so that the proper control algorithm could be chosen through the computer simulation. It could be concluded that the P-control algorithm was sufficient to control the electrohydraulic steering system, where the control frequency should be no greater than 20 Hz at the P-gain of 5. In particular, the performance of the developed steering controller was satisfactory even at the conditions of varying flow rates and loads.

Design, development and testing of a low-cost electric powered wheelchair for India

Purpose. To design and develop an appropriate, low-cost electric powered wheelchair (EPW) for the Indian subcontinent.Method. We performed the following multi-phase design process: (1) Conceptual design; (2) System design, Prototype I fabrication, focus group testing with Indian stakeholders (n = 29); (3) System re-design, Prototype II fabrication and user trials with US (n = 5) and Indian (n = 25) subjects.Results. (1) Preliminary investigations revealed that a conventional EPW design was infeasible due to the high component cost. Instead, we constrained our design to incorporate a single drive motor and manual steering, with the option of upgrading to power steering where economically feasible. (2) The first prototype was fabricated out of easily available, low-cost materials. Focus group testing demonstrated feasibility of the design and revealed differences between stakeholder groups. (3) Prototype II incorporated feedback from the first focus group and a needs assessment. US subjects provided valuable design advice prior to the India trials. Indian subjects travelled further in the SIMPL-EPW than their own manual wheelchair (MWC). Depending on spinal injury level, Indian subjects found the entire (tetraplegia) or outdoor portion (paraplegia) of the obstacle course significantly less challenging in the SIMPL-EPW compared with their own MWC.Conclusions. We demonstrated a useful and successful multi-phase design approach for developing assistive technology for developing regions.

11810 支援操舵から手動操舵への切り替え時における運転者の従事度合が緊急回避制御に及ぼす影響(人間工学,一般講演,学術講演)

11810 支援操舵から手動操舵への切り替え時における運転者の従事度合が緊急回避制御に及ぼす影響(人間工学,一般講演,学術講演)

10201 支援操舵から手動操舵への切り替え時における適応動作(生体工学)

This study examined a time driver needs to adapt to characteristic of vehicle after assisted steering is changed to manual steering. The experiment used a driving simulator. The level of driver's involvement in driving (the concerned level) was "Holding a steering wheel and front gazing (Pattern A)" and "Not holding a steering wheel and not front gazing (Pattern B)". The experimental condition was "lane change" and "side wind". As a result, in the case of Pattern A, driver needs 1 second to adapt to characteristic of vehicle in lane changing and 3 seconds in side wind. In the case of Pattern B, driver needs 2 seconds to adapt to it in lane changing and 3 seconds in side wind.

支援操舵から手動操舵への切り替え時における運転者の従事度合が制御動作に及ぼす影響

支援操舵から手動操舵への切り替え時における運転者の従事度合が制御動作に及ぼす影響

フォールトトレラントなステアバイワイヤ装置の信頼性と安全性解析

A structural design is proposed for a fault tolerant steer-by-wire (SBW) system consisting of a principal and a standby SBW unit together with a manual backup. A fault tree is constructed for a top event, complete loss of Minimal cut sets are derived accordingly. Operation rules are derived for degraded system states with partial failures before causing a minimal cut set. A transition diagram is depicted to summarize the rules. Low level SBW control rules are also proposed for sensor failures of monitoring vehicle states. Experiments using driving simulator are performed to examine the operation and control rules from a safety point of view, indicating 1) fault tolerant drivability for steady driving including constant radius turns, and 2) potential vehicle unstabilities during unsteady pylon slalom driving when the SBW is switched into a manual steering.

HOW TO MAKE STEER-BY-WIRE FEEL LIKE POWER STEERING

In this paper for the design of a Steer-by-Wire (SbW) system a generic controller structure is proposed with bidirectional position feedback. The design goal for SbW here is to match the dynamics of an (electric/hydraulic power) steering system which may notionally be subdivided into a manual and an assistance steering part. For matching the manual steering part a generic linear controller structure and for matching the assistance steering part a nonlinear unilateral controller structure are suggested. The controller design problem is formulated as a system dynamics equivalence problem, either based on a physical or an identified model, and is solved exactly. This result is then adapted according to practical considerations. For robustness and stability analysis of the linear part of the steer-by-wire system passivity theory is applied and performance is evaluated by Bode magnitude plots and a H∞-performance criterion. Nonlinear simulations at various operating conditions (vehicle speed, road/tire contact) with a high fidelity vehicle dynamics model demonstrate the robustness of the whole system.

Performance Analysis of Drive‐Line Steering Methods in Excavator‐Mounted Sheet‐Piling Systems

Sheet‐piling processes pose the problem of guiding the pile to follow a fixed trajectory in order to drive it correctly into the ground. Since the complete system consists of the supporting excavator boom with hydraulic actuators, the gripper, and the vibratory unit, the large number of system variables implies the use of servo control to allow a human operator to handle the operation. An exact inverse kinematic transformation from Cartesian workspace to boom joint space variables allows the pile penetration to be guided, keeping the valve input of the main boom actuator as the free parameter, while the remaining actuators are governed automatically by the control computer. The penetration record of the pile differs based on whether a constant valve input is used in semiautomatic steering mode or, alternatively, the desired penetration speed is governing the valve input in a feedback loop in full‐automatic steering mode. A numerical model representing an actual industrial system has been developed. Variable results from computer simulations have led the manufacturer to realize the steering system. It has been verified in real piling tests that the steering system may be tuned to be stable and fast enough for practical working conditions. In particular, the performance of trajectory control in terms of tracking error is much better than in the conventional manual steering method, as expected.

A rendezvous navigation algorithm for orbit determination, based on visual measurements by space vehicle crew members

At present, various radio navigation systems are employed during the automated approach of a transport vehicle to a space station. Experience has shown that emergency situations can occur in which it is necessary to revert to manual override of the automatic approach. Such situations have indeed occurred during flight operations of the space station Mir. The crews of the transport vehicles and the Mir used manual steering more than 30 times for successful docking, and four times for approach to the station. Successful manual steering demands absolute understanding of the relative orbit parameters. The decisive task of the crew is to determine these relative parameters. This is possible using visual observations from either the transport vehicle or the station using simple and reliable instruments. This article explains the algorithm for determining the relative orbits from visual crew observations, based on similarities of relative orbit families.

Experimental Comparison of Manual and Voice Controls for the Operation of in-Vehicle Systems

Many previous research studies have found that the operation of in-vehicle systems while on-the-move using traditional manual controls (buttons, switches etc.) can adversely affect driving performance. It has been proposed that voice operation can reduce these effects by allowing the eyes to remain on the road, and the hands to remain on the steering wheel. A counter-argument to the incorporation of voice control is that, by mounting manual controls on or near the steering wheel, similar benefits can be experienced. To examine these arguments, a study was designed to compare different types of control for operating an in-car entertainment (ICE) system, incorporating radio, tape and CD functions. Thirty two participants carried out tasks using either (i) standard manual ICE controls, (ii) manual steering wheel button controls, (iii) voice controls with spoken and visual feedback, or (iv) voice controls with no feedback. The ICE was operated alone, or while carrying out a simultaneous PC-based driving task using steering wheel and pedals. Driving performance was found to be significantly better while using voice controls than the manual controls. Transaction times while driving were shortest for the standard controls, intermediate for the voice conditions, and longest for the steering wheel controls. Subjectively, the voice controls with feedback were rated easiest, most likeable, and most efficient to use while driving.

On the Instability Criterion of the Autopilot Steering of Ships (1 st Report)

The recent trend in ship design brought out fuller and beamier ships with poorer course stability. Naval architects are anxious about a remarkable loss of propulsive power which will be caused by such poor stability.On the instability criterion of manual steering, we already discussed from the view point of phase compensation ability of helmsman1), 2). In the present study, the same problem will be discussed on autopilot steering in open sea, utilizing the performance criterion of autopilot navigation1), 2).In this first report, we provide the method of calculation with some examples and discuss about the results.The numerical calculations were carried out by the frequency response analysis. This method is useful if the system is linear and each component of the system is known. The disturbance consists of wave and wind. Each spectrum and response amplitude operator are reasonably evaluated.By the calculations using E 10 (E Series ship with L/V=10 sec), it is found the following facts. If the system stability becomes inferior by the ship herself or by autopilot coefficients, low-frequency yawing grows by wind. On the other hand, high-frequency disturbance of wave causes large amount of rudder movement according to the increase of rate control in autopilot. However, this steering only acts for resistance and scarcely reduces yawing.Further investigation concerning to the effect of L/V, the relation between the phase margin of the system and the energy loss etc. will be dealt with in the second report.