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Road condition evaluation is a critical part of gravel road maintenance. One of the parameters that are assessed is loose Gravel. An expert does this evaluation by subjectively looking at images taken and written text for deciding on the road condition. This method is labor-intensive and subjected to an error of judgment; therefore, it is not reliable. Road management agencies are looking for more efficient and automated objective measurement methods. In this study, acoustic data of gravel hitting the bottom of the car is used, and the relation between these acoustics and the condition of loose gravel on gravel roads is seen. A novel acoustic classification method based on Ensemble bagged tree (EBT) algorithm is proposed in this study for the classification of loose gravel sounds. The accuracy of the EBT algorithm for Gravel and Nongravel sound classification is found to be 97.5. The detection of the negative classes, i.e., non- gravel detection, is preeminent, which is considerably higher than Boosted Trees, RUSBoosted Tree, Support vector machines (SVM), and decision trees.

Conventional road condition evaluation is an expensive and time-consuming task. Therefore data collection from indirect economical methods is desired by road monitoring agencies. Recently intelligent road condition monitoring has become popular. More studies have focused on automated paved road condition monitoring, and minimal research is available to date on automating gravel road condition assessment. Road roughness information gives an overall picture of the road but does not help in identifying the type of defect; therefore, it cannot be helpful in the more specific road maintenance plan. Road monitoring can be automated using data from conventional sensors, vehicles' onboard devices, and audio and video streams from cost-effective devices. This paper reviews classical and intelligent methods for road condition evaluation in general and, more specifically, reviews studies proposing automated solutions targeting gravel or unpaved roads.

This paper presents a mobile robot prototype used for mallard navigation in a paddy field. One shortcoming of rice-duck farming is that a flock of mallards tends to gather in a specific area that produces a spring pond. This study was designed to develop a prototype of an autonomous mobile robot that guides a mallard flock to achieve highly efficient rice-duck farming. We developed a robot and waterproof boxes used for the protection of electric devices, including motors. The robot body is 270 mm long, 210 mm wide, and 250 mm high. Its body width is less than the length between rice stalks. After checking the waterproof capability for the body waterproof box, we conducted an indoor driving test for manual operation. Moreover, we conducted an outdoor evaluation tests to assess running on a gravel road and on a snowy road. We evaluated the robot performance not only for uneven surface roads including steps, but also for the range of wireless communication for controlling the robot.

One of the main objectives for vehicle designers is to achieve flat, safe ride in any environmental conditions. When a vehicle is moving along the road it is exposed to vibrations in multiple axes and directions. Vehicle behavior is extensively investigated in reference to road imperfections that could be expressed as single step disruptions, like remote bumps on the road. A simulation model, previously designed, was already used to investigate vehicle behavior, when riding over the step inputs. This model is further upgraded and now can perform simulations of the scenarios when vehicle is subjected to continuous imperfections on the road, like long runs of the gravel road in the country areas. Vehicle behavior is analyzed for few, common, speed levels in such scenarios. We can achieve lover amplitudes of pitch vibrations driving with the certain speed, but far the best outcome is obtained when active suspension is applied.

Recently, electrical welfare vehicles with free casters are widely used by patients and elders indoors. However, welfare vehicles may not be able to move well on gravel or dirty roads as seen in suburbs. In order to expand driving area, the skid steer mechanism is focused on. The skid steer vehicle (SSV) has been used for its high traveling ability on rough road. However, the SSV has disadvantage that the driving assistance is required because its steering is highly affected by road conditions. In this paper, a driving assistance control of SSV using the model error compensator and state estimator, i.e. EKF and cornering power estimator is proposed. The maneuverability is evaluated by correlation coefficient of joystick operation comparing asphalt road and gravel road.

Recently, welfare vehicles are widely used by patients and elders indoors, and many welfare vehicles with free casters drive indoors. However, the vehicle with free casters may not be able to move well on gravel or dirty road as seen in rural yard. In order to expand driving area for welfare vehicles, it is necessary to apply a new mechanism on the rough road. To design compact welfare vehicles for outdoor use at low cost, the skid steer mechanism is focused on. The skid steer vehicle (SSV) has been used for its high traveling ability on rough road. However, the SSV has disadvantage that the maneuvering assistance is required because its steering is highly affected by road condition. This study aims a driving assistance of SSV for patients and elders by using Model Error Compensator (MEC) that suppresses the modeling error. The proposed controller consists of MEC, Extended Kalman Filter (EKF) that reduces sensor and system noise assuming the undulating and skiddy gravel road, and estimation of cornering power of SSV. The effectiveness of the proposed control system is confirmed by the outdoor driving experiment comparing asphalt and gravel roads.

220kV open type substation equipment's surface will readily accumulate industrial and natural filthy when they expose to outdoors in a long-term, and this situation will lead to the phenomenon of flashover. The Substation Water Washing Robot in this paper can transport the high pressure water jet equipment to the operating position by insulated telescopic boom, and then carry out water washing operation to substation insulators, surge arresters, electric equipment casing and others with the high purity water through RO reverse osmosis technology. robot can achieve a barrier-free travel in the area of substation outdoor road and grass or gravel road in the facilities religion with crawler mobile chassis; Using multistage combination insulation and insulated telescopic lifting arm structure to improve the stability of water flushing operation; Using wireless remote control to effectively reduce the intensity of manual work, improving the safety of operation and ensuring the operation safety.

The Quadruped walking robot “JINPOONG” is developed to be able to walk in the field which is use to detection, surveillance, reconnaissance, security, and assistance. It can move, carry the luggage of 60kg or more and walk at the uneven terrain such as gravel road and slope of 15 degrees or more. By adjusting the length of the leg caused by the ground reaction force and body posture balance control to the sagittal and lateral plane it is possible to walk stably on the uneven terrain. In this paper, we describe a method for the stable walk on the uneven terrain of JINPOONG and show experimental results about varied terrain.

The quadruped walking robot “JINPOONG” is developed to be able to walk in the field which is used to detection, surveillance, reconnaissance, security, and assistance. It can move, carry the luggage of 60kg or more and walk at the uneven terrain such as gravel road and slope of 15 degrees or more. To the legged robot walking stable, when an external force is applied to the body, the posture control is necessary to maintain stability. In this paper, we describe a method for the stabilization posture of JINPOONG and show experimental results about the external force.

The embankment load which under driving and a variety of natural factors, can have sufficient strength and stabiLity, to ensure the traffic and safety of smooth flow. According to the nature of the highway, grade, and technical standards and the local natural conditions, develop the right foundation design, as the basis for the construction. In this paper, by the formation of cement stabiLized crushed stone soil strength theory, construction techniques, introduced quaLity control of highway construction, by degree of compaction of road bed analysis of the factors, described soil cement stabiLized gravel road bed construction precautions.

Currently, the mileage of highway in China is increasing rapidly, which demands a huge amount of raw construction material. At the same time, numerous tons of construction and demolition waste (CDW) is produced during the city regeneration process, some of which is thought can be reused in roadbed, sub-base, asphalt gravel road and concrete road surface. This study examined the technical feasibility and economic efficiency of CDW re-usage in road construction, and explored new methods to deal with the recycling materials. There is a significant meaning for highway construction engineering and CDM recycling.

The heat stability of embankment with different road surfaces on the permafrost regions containing rich moisture in the eastern Plateau at a rising speed of 0.04°C/a for the air temperature is modeled by numerical methods, and the critical heights of embankment were figured out by a regression analysis of the results, respectively for asphalt-paved, concrete and gravel road surfaces, according to the local natural geologic, geographic and meteorological conditions along the National Road 214. The modeled results are compared with that without climate warming, i.e. at a rising speed of 0.0°C/a for the air temperature. From the results, under the three types of road surfaces, the thermal stable critical heights are, respectively, 5.0 m actually not existing), 3.50 m, and 2.50 m for the rising speed of 0.04°C, and 4.50 m, 1.60 m, and 1.00 m without climate warming, there are obvious differences between two same road surfaces with and without climate warming. It is proved that the protection and cooling embankment measures on permafrost regions should be applied to lift the permafrost table under roadbed and insure the roadbed stability.