The present disclosure relates to a control system for winter maintenance vehicles, specifically a control system adapted for improved safety and efficiency of snow plow vehicles.
Winter maintenance vehicles, such as snow plows, are used to remove snow and ice from roadways, sidewalks, parking lots, etc. Snow plow vehicles are mostly manually operated on-road vehicles where the operators drive the vehicle, control the plow blade, and activate salt or brine dispensing. The manual multitasking by the operator leads to concerns over safety, operational efficiency, and environmental impact.
In regards to safety concerns, snow plow vehicles are often large in size and may be difficult to navigate through narrow city streets that are often congested with obstacles such as curbs, signs, light posts, parked cars, etc. Further, snow plow vehicles often operate under adverse weather conditions where road conditions are at their most treacherous, which demand the operator's utmost attention. As mentioned, the operator may also have the added responsibility of operating various vehicle components, such as de-icing/snow removal material dispensers. The foregoing is likely to result in an elevated level of snow plow related incidents that may be of considerable cost to municipalities and that could also result in personal injuries. In some cases, medium to large sized municipalities pay an average of $500,000 a year in damaged property claims and settlements from accidents caused by snow plow vehicles.
With respect to operational efficiency and environmental impact, it is understood that the manual operation of salt or brine dispensing units by the snow plow operator is inexact and often leads to over application. Not only does over-salting or over application result in increased cost, its negative environmental impact is also well known. Salt distribution is often inexact because the current solutions lack closed-loop salt measurement and control. Currently, about five million tonnes of road salt are used in Canada each year, which costs approximately $250 million dollars. Over $5 billion dollars of damages to Canadian infrastructure may be directly attributable to salt on the roadways.
Over-salting can also lead to increased salinity in waterways, causing irreparable harm to wildlife and the environment. If municipalities could measure the amount of salt applied to roads and work to reduce it, there would be a significant benefit to their operating costs, their townships and the environment.
Accordingly, there is a need for an improved snow plow vehicle control system which enhances vehicle operation safety and minimizes vehicle operator responsibilities with regards to non-driving tasks.
To at least partially overcome some of the above-mentioned challenges, in one aspect, the present disclosure provides a winter maintenance vehicle control system that reduces de-icing/snow removal material dispensing control from the operator's responsibility. The dispenser operation may be monitored to determine the amount of de-icing/snow removal material dispensed and used to regulate the rate at which the material is dispensed. The closed-loop system may automate the material dispensing procedure by being able to apply quantifiable amounts of de-icing/snow removal material on the roads more consistently. In some embodiments, the material dispensing operation may also be varied based on a pre-determined profile containing desire dispensing volume data based on geographical locations with corresponding weather data and other relevant factors, which may increase the safety of operators, minimize municipality liability, increase operational efficiency, and reduce material costs.
In some further embodiments, the material dispensing operation decisions for one or more winter maintenance vehicles may be determined and/or coordinated at a centralized command center rather than at each local truck. The use of a centralized command center ensures someone is observing the trucks and their functions. If the weather changes, a central agent is able to respond and makes changes accordingly. This may be done using a cloud base server.
In another aspect, the present disclosure provides a winter maintenance vehicle control system with a collision avoidance feature. Specifically, an array of sensors may be incorporated into the vehicle so as to enable the control system to differentiate between accumulation of snow and ice from objects to be avoided. In some embodiments, the identification of objects to avoid may be made even though the object is partially or fully covered in snow. In further embodiments, radar sensors may be used since they are able to penetrate through snow and ice and reflect energy back. In some embodiments, a control signal may be sent to change the position of one or more of the plow blades to avoid potential collisions. In other embodiments, the vehicle operator may be notified of a possible collision in order to enable them to take corrective action. In other embodiments, LiDAR is used.
In a still further aspect, the present disclosure provides a control system for a winter maintenance vehicle having a dispenser for dispensing a material, the dispenser being connected, via an output path, to a storage unit for storing the material, the storage unit having at least an opening for allowing the material to flow therefrom to the output path, the opening controlled by at least one control valve, the control system comprising: a sensing mechanism configured to detect an amount of material dispensed through the output path; and a controller operatively coupled to the control valve and the sensing mechanism, the controller configured to send a control signal to the control valve based on the detected amount of dispensed material.
In a still further aspect, the present disclosure provides a control system for a winter maintenance vehicle that includes a plow, the control system comprising (i) a sensor array comprising a first sensor configured to determine the plow position relative to the vehicle, and a second sensor configured to detect a plurality of encountered objects; and (ii) a controller coupled with the sensor array, the controller configured to determine a footprint of the vehicle based on the plow position, to make an identification with respect to the plurality of encountered objects, and to determine potential collisions based on the determined footprint and identification.
This footprint may be dynamically based on the extension and retraction of the blades. Movement of the wing also often greatly changes the width of the vehicle. The controller is further configured to assess a likelihood of collision based on the determined footprint and identification.
In a further aspect of the present disclosure, a control system is provided with collision avoidance feature. Even though automobile collision avoidance systems are well known in the art, existing systems are often unsuitable for the operating conditions associated with winter maintenance vehicles such as snow plow vehicles. Specifically, the accumulation of snow and ice on road surfaces could trigger false detection, which could lead to inefficient snow/ice removal operation as piles of snow and ice are avoided and not removed. Further, irregular shapes/outlines of snow/ice accumulation may also not serve as a distinguishing feature since common snow plow collision objects, such as parked vehicles, guardrails, and base of light posts, may be partially or completely buried under snow and ice. The inability of existing collision avoidance systems to distinguish between obstacles and snow/ice accumulation may lead to collisions and property damage as well as potential injuries.
The present disclosure presents an improved collision avoidance system for a snow plow vehicle control system that at least partially addresses some of the deficiencies of known collision avoidance systems identified above.
Reference will now be made, by way of example, to the accompanying drawings which show example embodiments of the present application, and in which:
Similar reference numerals may have been used in different figures to denote similar components.
The present disclosure is made with reference to the accompanying drawings, in which embodiments are shown. However, many different embodiments may be used, and thus the description should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete. Like numbers refer to like elements throughout. Separate boxes or illustrated separation of functional elements of illustrated systems and devices does not necessarily require physical separation of such functions, as communication between such elements may occur by way of messaging, function calls, shared memory space, and so on, without any such physical separation. As such, functions need not be implemented in physically or logically separated platforms, although they are illustrated separately for ease of explanation herein. Different devices may have different designs, such that although some devices implement some functions in fixed function hardware, other devices may implement such functions in a programmable processor with code obtained from a machine readable medium. Elements referred to in the singular may be implemented in the plural and vice versa, except where indicated otherwise either explicitly or inherently by context.
Other examples and corresponding advantages may be readily discernible in view of the present disclosure.
Reference is first made to
Situated behind cab 14 is often a storage unit or hopper 16 configured for storing a material 18 to be dispensed for de-icing and/or snow removal purposes. In some embodiments, the hopper 16 may be installed in the middle of the vehicle 10, known as a cross-conveyor configuration. As it is known to those skilled in the art, the material 18 may include any suitable mixture or compound having a low freezing point and/or is capable of increasing road surface friction. The material 18 may be in granular form such as rock salt, sand, gravel, and other types of salt (calcium chloride and magnesium chloride). Alternatively, the material may be in liquid form such as brine, a type of salt-based solution, beet juice, or any other liquid used for de-icing/snow removal purposes.
As shown, the hopper 16 is coupled to a dispenser 20 near the back end of the vehicle 10 through an output path 22. It may be appreciated by those skilled in the art that for embodiments with a front discharge or cross conveyor configurations, the dispenser 20 may be positioned between hopper 16 and the cab 14. The dispenser 20 is configured to dispense the material 18 onto a road surface upon which the vehicle 10 travels.
As shown in
At least a portion of the output path 22 may be defined by the feed conveyor 26, which transports the material 18 in the direction as indicated by the arrow towards the dispenser 20. The feed conveyor 26 in the illustrated embodiment includes rollers 30, 32 configured to facilitate movement of a conveyor belt 34. It is to be appreciated that the conveyor belt 34 may be driven by any other appropriate means, such as a chain drive. As is known in the art, at least one of the rollers 30 and 32 is driven by a motor (not shown). The rollers 30, 32 facilitate movement of the conveyor belt 34 in a given direction such as in a clockwise direction as indicated by the arrow in
Once the material 18 is delivered into the dispenser 20, a rotating member, or a spinner 36, of the dispenser 20 may dispense the material 18 onto a road surface below (not shown). As known to those skilled in the art, the spinner 36 is generally used for material 18 in granular form. For material 18 in liquid form, a spray faucet or any other type of solution dispenser may be used instead of, or in conjunction with, the spinner 36. It is to be appreciated that other forms of dispensing component may be used. The rotation speed of the spinner 36 may depend on the number of lanes across which the material is to be dispensed. The rotating member may include two or more spinners.
In the illustrated embodiment, the control system 40 includes a controller 42 that is in connection with a sensing mechanism 44. The sensing mechanism 44 may be secured proximate to the output path and configured to detect an amount of material 18 outputted from the storage unit to the dispenser 20. For example, in one embodiment the amount of material 18 detected by sensing mechanism 44 may be a volume of material 18 outputted from the storage unit to the dispenser 20.
In some embodiments, such as the one shown in
In some embodiments, the LiDAR sensor 46 may first be calibrated by measuring the distance Y to conveyor belt 34 without the presence of any material 18. This initial Y value may be set as a reference distance. After material 18 is dispensed onto the conveyor belt 34 as shown in
In order to determine the volume of the dispensed material 18, the depth of the material along the longitudinal direction of the conveyor belt 34 is also determined. In some embodiments, the depth of the material 18 along the conveyor belt 34 may be determined using a conveyor encoder 35, as shown in
Hence, a volume of the dispensed material 18 can be determined by using V=ΔY*X*D for each segment 52. Summation of the volume, V, for all segments 52 would provide the total volume snapshot per encoder pulse.
The amount of material 18 outputted from the storage unit to the dispenser 20 and detected by sensing mechanism 44 is described above as one of volume. As understood by the skilled person, in alternate applications, the amount of material 18 detected by sensing mechanism 44 may instead by one or more of volume, weight, area, and density of material 18.
For material 18 in liquid form, the sensing mechanism 44 may include any suitable liquid flow sensor, such as an inline flow meter, which may be used to measure volumetric flow rate of a liquid or gas.
It is to be understood by those skilled in the art that any other suitable forms of mounting mechanisms for positioning the sensing mechanism may be used. The mounting assembly 54 may be customized to allow the sensor 46 to be configured physically for optimum sensing angle and distance away from feed conveyor 26. In some embodiments, the LiDAR sensor 46 may be mounted onto the hoist cylinder between the cab 14 and the hopper 16. In some other embodiments, the sensor 46 may be mounted onto the metering gate. The sensor 46 may also be mounted to any other location on the vehicle 10 so long as the sensor is capable of monitoring the output path 22. A pneumatic device may be mounted proximate to the sensor 46 in order to produce a constant air flow past the sensor 46 to ensure the sensor 46 stays clean.
Referring back to
In some embodiments, information from available a third-party database 72 may be obtained by the remote server 74 and used to create a pre-determined de-icing/snow removal material application profile 76 by remote server 74. In some embodiments, the remote server 74 may be a cloud-based web server with corresponding web applications to handle queries, such as in a SQL format, firebase, firecloud, from snow plow vehicles 10.
The profile 76 may comprise information on desired volume of de-icing/snow removal material for sections of a route. The volume information in the profile 76 may be based on one or more of historical data, predicative modelling, environmental sensitivity, or another suitable basis. With respect to the third-party database 72, by way of a non-limiting example, the Ministry of Transportation of Ontario, Canada (MTO) maintains a Road Weather Information System (RWIS) which utilizes a network of road sensors, meteorological sensors, and cameras to monitor and collect weather information on roadways. In addition, weather forecast information may also be readily obtainable from various meteorological agencies, and may be integrated with the road weather information to generate a desirable salt/brine application profile 76 that may permit efficient use of de-icing/snow removal resources with improved effectiveness.
This information may be received through the remote service bidirectional communication. In some embodiments, real time changes can be made to the de-icing application. If the weather forecast worsens, a storm severity slider may be used. Each road is classified into a category to determine how much of each de-icing material should be dispensed. This feature includes predetermined set amounts to increase the dispensed material 18 when the slider is activated.
The generated profile 76 may be stored in a remote database 78. The profile 76 may be communicated to controller 42 via a vehicle communication unit 80. The profile 76 may be stored locally within a computer-readable memory 82 onboard the controller 42 such that when communication link with the remote server 74 is unavailable, de-icing/snow removal material dispensing operation may still commence. The memory 82 may also be used to store dispensed material volume data 84 as generated from the sensing mechanism 44. Volume data 84 may be in any suitable format, such as SQL data. In some embodiments, dispensed material volume information 84 may be uploaded from controller 42 to remote server 74 via communication unit 80. The remote server 74 may use the uploaded information to update existing profiles 76 or to be taken into consideration for future profiles 76. Subject to availability of communication link between communication unit 80 with the remote server 74, the profile 76 stored in memory 82 may be periodically updated based on the most recent data obtained from the third party server or database 72. For example, profile 76 may be updated on a week-to-week, day-to-day, or hour-to-hour basis, or continuously updated in real-time. In some embodiments, the vehicle GPS/GNSS data may also be uploaded to remote server 74 such that any uploaded dispensed material volume data 84 may be correlated with the location data by the remote server 74. Additionally, by locally storing the profile 76, the snow plow vehicle 10 may continue to execute de-icing/snow removal operation in offline mode where a communication link with the remote server 74 is unavailable.
In some embodiments, routes to be travelled by the snow plow vehicle 10 may be generated based on needs as determined with the road weather information and weather forecast. In other words, routes may be created for a given salt/brine application profile. Alternatively, a predetermined route may be created based on other factors, such as traffic volume and/or environmental sensitivity, and a corresponding salt/brine application profile may be created for the specific route. Further, in some instances as weather and road conditions change, real time changes could be made to application rates and profiles where a predetermined rate and profile has been provided to a vehicle. Heat maps, trends, and overall salt usage can be prepared for operational purposes, on a daily, shift-based, or seasonal basis.
The controller 42 may comprise a processor 86 which may be used to determine the dispensed material volume data 84 based on the sensing data provided by the sensing mechanism 44. Further, in some embodiments, the processor 86 may compare the dispensed material volume data 84 with that of the profile 76 and determine whether a discrepancy exists between the desired dispensing volume and the detected dispensed volume. The controller 42 may be connected to the control valve 28 of the hopper 16 such that the controller 42 is capable of sending a control signal 88 to the control valve 28 to change the size of opening 24 and thereby control the output rate of the material 18. The control signal 88 may be based on the CAN-bus protocol, which may be compatible with existing vehicle communication network. The control signal 88 may be generated based on the determined discrepancy between monitored material dispensing volume and the desired dispensing volume in the profile 76, and sent to the control valve 28 over the vehicle communication network.
By way of non-limiting examples, should the dispensed volume data 84 for a given location along a route exceed its corresponding desired volume as indicated by the profile 76, the controller 42 may send the signal 88 to the control valve 28 to decrease material output rate by decreasing the size of the hopper opening 24. Alternately, should the dispensed volume data 84 for a given point be less than its desired volume, as indicated by profile 76, the controller 42 may send a control signal 88 to control valve 28 to increase the size of the hopper opening 24.
In a further aspect of the present disclosure, a control system is provided with collision avoidance features. Even though automobile collision avoidance systems are well known in the art, existing systems are often unsuitable for the operating conditions associated with winter maintenance vehicles, such as snow plow vehicles. Specifically, the accumulation of snow and ice on road surfaces could trigger false detections, which could lead to inefficient snow/ice removal operation as piles of snow and ice are avoided and not removed. Further, irregular shapes or outlines of snow and/or ice accumulation may also not serve as a distinguishing feature, since common snow plow collision objects, such as parked vehicles, guardrails, and the base of light posts, may be partially or completely buried under snow and ice. The inability of existing collision avoidance systems to distinguish between obstacles and snow/ice accumulation may lead to collisions and property damage as well as potential injuries.
The present disclosure presents an improved collision avoidance system for a snow plow vehicle control system that at least partially addresses some of the deficiencies of known collision avoidance systems identified above.
The sensor array 142 includes a sensor to detect a plow position 148 and a sensor to detect incoming objects 150.
The plow sensing mechanism 148 is configured to detect plow positions of the main plow blade 12 as well as any wing plows in real-time. In some embodiments, the plow sensing mechanism 148 may include in-cylinder LVDTs (Linear Variable Displacement Transducers) 156 to determine cylinder stroke. The cylinder stroke measurements may be translated, by controller 144, into positional information in relation to the vehicle 10. In some further embodiments, to detect the position of the plow blades, the plow sensing mechanism 148 may include at least a position sensor 152 in combination with an angle sensor 154. In some embodiments, plow sensing mechanism 148 may be arranged in a “heel-and-toe” blades sensing configuration on the front and mid-rear plow blades. In some embodiments, a real-time GPS positioning locator 158 may be used, whereby the controller 144 may continuously track the position of the main plow blade 12 and wings in real-time.
The object detection mechanism 150 may be configured to detect objects within the travelling path of the snow plow vehicle 10. The object detection mechanism 150 may include a plurality of distance sensing elements 160 to permit the controller 144 to perform real-time signal processing of all distance measurement data provided by distance sensing elements 160 simultaneously so as to map the immediate area of concern, such as in front or to the side of the vehicle 10, and may designate the series of measurements as an “object”. In the case of snow plows, detecting an object to avoid has an additional level of complexity. As mentioned above, there is a need for the ability to distinguish between objects to avoid from accumulations of snow and ice.
In some embodiments, in addition to the plurality of distance sensing elements 160, the object detection mechanism 150 may include at least one object density sensor 162 that is capable of detecting object density. The controller 144 may be calibrated with the density value of snow and ice as a reference point, to enable it to perform object identification based on a density value greater than the reference point.
In some embodiments, the object detection mechanism 150 may include ground penetrating radars (GPR)s 164 capable of detecting depth, size, and material characteristics of objects under snow cover.
The controller 144 may be configured to receive the plow positional information and the object detection identification data, and to utilize them to determine a likelihood of collision with one or more identified objects to avoid. Specifically, in combination with the known dimensions of vehicle 10, the plow positional information may be used to determine, by controller 144, a footprint of the snow plow vehicle. The footprint would then be used to project the path of the vehicle based on vehicle data as provided by the vehicle controller 146, which may be in bi-directional communication connection with the controller 144. By way of non-limiting example, readings from the vehicle speedometer, groundspeed sensors, J1939 ECU messaging, and steering mechanism may be used to generate a projected path of the vehicle 10. The projected path may be overlain with the object identification to determine the likelihood of collision.
In some embodiments, when a potential collision is detected, a warning signal may be sent to a Human Machine Interface (HMI) situated within the cab 14, to notify the vehicle operator. In some further embodiments, the controller 144 may be configured to send a control signal to the vehicle controller 146 to automatically adjust the plow blade angle so as to minimize the footprint of the vehicle 10 and thereby avoid the potential collision, independent of operator control. In other instances, signals could be sent to the vehicle's braking and/or engine speed control systems in an attempt to avoid a collision.
The potential collision detection speed may be taken into account in order to allow the operator time to react and take evasive maneuvers if necessary. For example, the maximum speed for a successful notification may be calibrated for 100 km/h with the minimum distance for collision warning being 50 m. It is to be understood that the foregoing values may vary based on the speed limits, operating limits, maneuverability of the snow plow vehicle, road conditions, etc.
In some embodiments, the controller 144 may be implemented using 32-bit microprocessors, or better, and utilize a lean approach to the algorithm design to minimize processing time and enable real-time signal processing.
In addition to the above-mentioned sensing elements, the sensor array 142, the plow sensing mechanism 148, and the object detection mechanism 150 may include vision, ferrous, LiDAR, radar and/or various other sensing options. Further, any of the above-disclosed sensing elements may be implemented using suitable integrated sensors that are capable of performing the sensing functionalities of one or more of the above-disclosed sensors.
Certain adaptations and modifications of the described embodiments can be made. Therefore, the above discussed embodiments are considered to be illustrative and not restrictive.
This application claims the benefit of U.S. Provisional Application No. 62/862,790 filed on Jun. 18, 2019, which is incorporated by reference herein in its entirety.
Number | Date | Country | |
---|---|---|---|
62862790 | Jun 2019 | US |