Multi-use detection system for work vehicle

A work vehicle may include a chassis, a plurality of ground-engaging devices connected to the chassis and configured to provide support and traction to the chassis along a ground surface, an operator station connected to the chassis, and a rear object detection system configured to detect a presence of an object in an area at least partially rearward of the operator station. The rear object detection system may be further configured to detect a presence of a depression of the ground surface in the area.

FIELD OF THE DISCLOSURE

The present disclosure relates to a machine and a method. An aspect of the present disclosure relates to a backup detection system for a work vehicle and a method of alerting a user backing up a work vehicle.

BACKGROUND

Work vehicles may be operated in a forward mode in which the work vehicle travels in a certain direction, often the direction the operator is facing, and a reverse mode (backing up), often the opposite direction of the direction the operator is facing. Work vehicles may be equipped with a system to detect objects located behind the work vehicle.

SUMMARY

According to an aspect of the present disclosure, a work vehicle may include a chassis, a plurality of ground-engaging devices, an operator station, and a rear object detection system. The plurality of ground-engaging devices may be connected to the chassis and configured to provide support and traction to the chassis along a ground surface. The operator station may be connected to the chassis. The rear object detection system may be configured to detect a presence of an object in an area at least partially rearward of the operator station. The rear object detection system may be further configured to detect a presence of a depression of the ground surface in the area.

According to another aspect of the present disclosure, the rear object detection system may be configured to send radio waves, receive radio waves, and analyze the received radio waves to detect the presence of an object and the presence of a depression.

According to another aspect of the present disclosure, the rear object detection system may include a radio wave transmitter, a radio wave receiver, and a processor. The radio wave transmitter may be configured to transmit radio waves to the area. The radio wave receiver may be configured to receive radio waves traveling from the area to the radio wave receiver. The processor may be configured to analyze the received radio waves to detect the presence of an object. The processor may also be configured to analyze the received radio waves to detect the presence of a depression.

According to another aspect of the present disclosure, the processor may be configured to detect the presence of a depression by comparing the received radio waves to a baseline indicative of an absence of a depression of the ground surface in the area.

According to another aspect of the present disclosure, the processor may be configured to detect the presence of a depression by comparing a signal strength of the received radio waves to a signal strength of the baseline.

According to another aspect of the present disclosure, an operator seat may be included in the operator station. The area may be at least partially out of a line-of-sight of an operator seated in the operator seat.

According to another aspect of the present disclosure, the area may be at least partially out of a line-of-sight of the operator seat.

According to another aspect of the present disclosure, the area may be at least partially out of a line-of-sight of the operator station.

According to another aspect of the present disclosure, a work vehicle may include an upper chassis, a lower chassis pivotally connected to the upper chassis, a plurality of ground-engaging devices, an operator station, a sensor assembly, a rear object detection system, and a controller. The plurality of ground-engaging devices may be connected to the lower chassis and configured to provide support and traction to the work vehicle along a ground surface. The operator station may be connected to the upper chassis. The sensor assembly may be configured to provide a position signal indicative of the position of the upper chassis relative to the lower chassis. The rear object detection system may be connected to the upper chassis and configured to provide an object signal indicative of a presence of an object in an area rearward of the operator station. The controller may be configured to receive the position signal and the object signal and provide an alarm signal based on the position signal and the object signal.

According to another aspect of the present disclosure, the operator station may include an operator input. The operator input may provide a command signal indicative of a commanded direction of movement of at least one of the ground-engaging devices. The controller may receive the command signal and be configured to provide the alarm signal based on the position signal, the object signal, and the command signal.

According to another aspect of the present disclosure, the alarm signal may indicate an alarm when the position signal and the command signal indicate a commanded movement in a rearward direction for the upper chassis. The object signal may indicate the presence of an object in the area.

According to another aspect of the present disclosure, the rear object detection system, au be further configured to provide a depression signal indicative of a presence of a depression of the ground surface in the area. The controller may be configured to receive the depression signal and provide the alarm signal based on the position signal, the object signal, the depression signal, and the command signal.

According to another aspect of the present disclosure, the rear object detection system may include a radio wave transmitter, a radio wave receiver, and a processor. The radio wave transmitter may be configured to transmit radio waves to the area. The radio wave receiver may be configured to receive radio waves traveling from the area to the radio wave receiver. The processor may be configured to provide the object signal based on the received radio waves. The processor may also be configured to provide the depression signal based on the received radio waves.

According to another aspect of the present disclosure, the processor may be configured to provide the depression signal based on a comparison of the received radio waves to a baseline, where the baseline is indicative of an absence of a depression of the ground surface in the area.

According to another aspect of the present disclosure, the processor may be configured to provide the depression signal based on a comparison of a signal strength of the received radio waves to a signal strength of the baseline.

According to another aspect of the present disclosure, the alarm signal may indicate an alarm when the position signal and the command signal indicate a commanded movement in a rearward direction for the upper chassis, and the depression signal indicates the presence of a depression in the area.

According to another aspect of the present disclosure, a method may include transmitting radio waves into an area rearward of a work vehicle, sensing radio waves received from the direction of the area, providing an object signal indicative of a presence of an object in the area based on the sensed radio waves, providing an depression signal indicative of a presence of a depression of the ground surface in the area based on the sensed radio waves, receiving a command signal indicative of a command from an operator to move the work vehicle along a ground surface, activating an object alarm if the object signal indicates the presence of an object and the command signal indicates a command to move the vehicle rearward, and activating a depression alarm if the depression signal indicates the presence of a depression and the command signal indicates a command to move the vehicle rearward.

According to another aspect of the present disclosure, the method may include receiving a position signal indicative of a position of an upper chassis of the work vehicle relative to a lower chassis of the work vehicle and activating the object alarm if the object signal indicates the presence of an object and (i) the command signal indicates a command to move the lower chassis of the vehicle rearward and the position signal indicates a heading of the upper chassis is within 90 degrees of a heading of the lower chassis or (ii) the command signal indicates a command to move the lower chassis of the vehicle forward and the position signal indicates the heading of the upper chassis is not within 90 degrees of the heading of the lower chassis.

According to another aspect of the present disclosure, the method may include receiving a position signal indicative of a position of an upper chassis of the work vehicle relative to a lower chassis of the work vehicle and activating the depression alarm if the depression signal indicates the presence of a depression and (i) the command signal indicates a command to move the lower chassis of the vehicle rearward and the position signal indicates a heading of the upper chassis is within 90 degrees of a heading of the lower chassis or (ii) the command signal indicates a command to move the lower chassis of the vehicle forward and the position signal indicates the heading of the upper chassis is not within 90 degrees of the heading of the lower chassis.

According to another aspect of the present disclosure, the method may include providing a first tone pattern upon activation of the object alarm and a second tone pattern upon activation of the depression alarm, where the first tone pattern is different than the second tone pattern.

The above and other features will become apparent from the following description and accompanying drawings.

Like reference numerals are used to indicate like elements throughout the several figures.

DETAILED DESCRIPTION

FIG. 1andFIG. 2illustrate work vehicle100including lower chassis102in contact with a ground surface and upper chassis104connected to lower chassis102. Lower chassis102, which may also be referred to as an undercarriage, supports work vehicle100and provides tractive effort through ground-engaging devices106. Ground-engaging devices106provide support and traction to work vehicle100along a ground surface, and may be driven by an engine of work vehicle100to drive work vehicle100forward or rearward. Ground-engaging devices106are illustrated as a pair of tracks but may alternatively be wheels in other embodiments. Work vehicle100is illustrated as an excavator, but may be any number of construction, forestry, or other off-road work vehicles.

Upper chassis104is pivotally connected to lower chassis102so as to allow upper chassis104to rotate 360 degrees about lower chassis102, which may also be referred to as slewing or swinging. Due to this arrangement, upper chassis104may be oriented in any direction (i.e., heading) relative to lower chassis102. While movement by lower chassis102results in movement of upper chassis104in the same direction relative to the ground, the direction of movement experienced by an operator in operator station108may vary depending on the orientation of upper chassis104relative to lower chassis102. For example, inFIG. 1upper chassis104is oriented in the same direction as lower chassis102, and thus forward movement of lower chassis102results in forward movement for upper chassis104. Conversely, inFIG. 2upper chassis104is oriented in the opposite direction as lower chassis102, and thus forward movement of lower chassis102results in rearward movement for upper chassis104and movement in rearward direction108b. Work vehicle100may be referred to as traveling rearward, reversing, in a reverse mode, or backing up when operator station108is moving in rearward direction108b, which is rearward relative to the direction of operator109seated normally in operator station108, even if the lower chassis102is moving in a forward direction.

Sensor assembly110is positioned near the pivotal joint interconnecting upper chassis104and lower chassis102, and is configured to provide a position signal indicative of the position of upper chassis104relative to lower chassis102. For example, sensor assembly110may be a rotary position sensor which is configured to measure the relative angle between upper chassis104and lower chassis102. Alternatively, sensor assembly110may be a switch which is configured to detect whether upper chassis104is positioned in the same direction as lower chassis102(i.e., the heading of upper chassis104within 90 degrees of the heading of lower chassis102), or an opposite direction as lower chassis102(i.e., the heading of upper chassis104is 90-270 degrees away from the heading of lower chassis102). As another alternative, sensor assembly110may consist of a first sensor disposed on lower chassis102and configured to provide a first direction signal indicative of the direction of lower chassis102and a second sensor disposed on upper chassis104and configured to provide a second direction signal indicative of the direction of upper chassis104. The relative positioning of lower chassis102and upper chassis104may then be determined by comparing the first direction signal and the second direction signal.

Sensor assembly110may communicate its measurement to a controller on work vehicle100, such as controller112. Controller112may then determine the expected direction of movement of upper chassis104based on the measurement from sensor assembly110and the operator's commanded direction of movement for lower chassis102. For example, if controller112receives an operator command signal indicating a command for forward movement of lower chassis102and receives a position signal from sensor assembly110indicating that upper chassis104is positioned 180 degrees relative to lower chassis102(i.e., the forward direction for upper chassis104is the same as the rearward direction for lower chassis102), controller112can determine that upper chassis104will be moving in its rearward direction and thus operator station108will be moving in rearward direction108band work vehicle100will be reversing.

Operator station108is mounted on upper chassis104, and configured to provide a place for an operator to control work vehicle100, such as operator109. Operator109is seated within operator station108on operator seat111, and from this position operator109may input drive commands for work vehicle100, such as commanding lower chassis102to move in a forwards direction or a rearwards direction. The operator may input these commands through the use of one or more pedals. For example, the operator may depress a pedal in a forward direction to command forward movement of ground-engaging devices106and depress the same pedal in a backward direction to command reverse movement of ground engaging devices106. The operator may also be able to command the left and right ground-engaging devices106of work vehicle100at differing rates, such as commanding the left ground-engaging devices106forward at a greater speed than the right ground-engaging devices106to turn the vehicle rightward, or in differing directions, such as to turn the vehicle sharply or rotate it in place.

When seated within operator station108, operator109may have direct visibility in forward direction108aof operator station108, and operator109may turn his or her head while seated to look in rearward direction108bof operator station108. However, operator109may not have full visibility around the periphery of work vehicle100. For example, while looking in rearward direction108bof operator station108, the lowest operator109would be able to see from a seated position on operator seat111are objects at or above sight-line113, which is the sight-line from the operator to a top portion of upper chassis104. Certain areas surrounding the upper chassis104may not have any direct line-of-sight to an operator seated on operator seat111.

Operator station108may also include an operator display114which may be used to display information relating to work vehicle100, such as information about what is immediately behind work vehicle100, or which may be used by the operator to input commands or data. Operator display114may also be capable of generating sounds for the operator, including warning tones or speech, but in alternative embodiments a separate device such as a standalone speaker may be utilized for audio communications. Operator display114is in communication with controller112, enabling controller112to communicate with operator display114to display messages or generate audible warnings or speech for the operator.

Work vehicle100is equipped with a rear object detection system (RODS)116which is mounted to the rear of upper chassis104. RODS116is connected to upper chassis104and faces outward from the rear of upper chassis104, giving a line-of-sight to the ground and objects behind upper chassis104. RODS116may be utilized to detect objects located behind upper chassis104within a certain distance of work vehicle100, the distance determined by the capabilities of RODS116. In this embodiment, RODS116utilizes radar to sense objects located behind work vehicle100in area118, but other detection systems may utilize different sensing technologies, including laser (e.g., lidar), sound (e.g., ultrasound/sonar), or image capture (e.g., via one or more cameras). RODS116comprises a radio wave transmitter, a radio waver receiver, and a processor. RODS116functions by generating radio waves and transmitting them rearward of operator station108and rearward of upper chassis104, into area118via the radio wave transmitter, receiving (i.e., sensing) the radio waves after they are reflected off surfaces behind upper chassis104and return to RODS116via the radio wave receiver, and analyzing the sensed data to determine whether objects are present via the processor. In RODS116, the radio wave transmitter and radio wave receiver may both be included in a transceiver, a component capable of transmitting and receiving radio waves.

In normal operation, RODS116may be configured to detect an object rearward of operator station108and rearward of upper chassis104by determining whether it senses an object closer than a threshold distance, which may be pre-set or adjustable so as to avoid the ground setting off RODS116. RODS116may also be configured so as to require a detected object be larger than a threshold size before being considered an object, and this threshold size may be pre-set or adjustable, such as based on the distance to the object. In the embodiment illustrated inFIG. 1andFIG. 2, RODS116includes a processor which analyzes the sensed radio waves to determine whether an object is present in area118and then communicates an object signal indicative of the presence of an object in area118to controller112. In the embodiment illustrated inFIG. 1andFIG. 2, the object signal from RODS116is a value which indicates the absence of an object (e.g., 0) or the proximity of the object to RODS116(e.g., 1, 2, or 3 as the proximity increases). In alternative embodiments, the object signal from RODS116may not itself communicate the presence or absence of an object in area118, but may instead communicate a value representative of the signal strength of the radio waves received by RODS116(e.g., from 1-100) which is indicative of the presence of an object in area118(or the absence of such an object), and controller112may perform further determines using this object signal (e.g., indicating an object if the object signal is 50 or greater). In yet other alternative embodiments, RODS116may communicate other data to controller112, or data in an alternative format, to allow controller112to determine whether an object is present in area118.

In the embodiment illustrated inFIG. 1andFIG. 2, RODS116communicates to controller112whether an object is detected rearward of upper chassis104, within area118. In alternative embodiments, RODS116may communicate further information such as the size of, or distance to, the detected object, to enable controller112to take different actions based on the size or distance of the detected object. Area118is located rearward of operator station108and rearward of upper chassis104, and is not within a direct line-of-sight to an operator seated on operator seat111, such as operator109, although portions may be visible through indirect lines-of-sight such as via mirrors placed on work vehicle100. In alternative embodiments, area118may not be located entirely rearward of upper chassis104, but may instead be located only partially rearward of upper chassis104, or may not be entirely outside a direct line-of-sight to an operator seated on operator seat111.

FIG. 3,FIG. 4, andFIG. 5illustrate a work vehicle200, which includes RODS216. Similar toFIG. 1,FIG. 3illustrates work vehicle200with the upper chassis104oriented in the same direction as the lower chassis, and thus forward movement of the lower chassis102results in forward movement for the upper chassis104. Similar toFIG. 2,FIG. 4illustrates work vehicle with upper chassis104oriented in the opposite direction as lower chassis102, and thus forward movement of lower chassis102results in rearward movement for operator station108and upper chassis104.

RODS216, like RODS116, utilizes radar to detect objects rearward of operator station108and upper chassis104in area118. Unlike RODS116, RODS216is configured to additionally detect the presence of a depression in the ground surface below and rearward of operator station108and upper chassis104in area218, and communicate a depression signal to controller112indicative of a presence of a depression in area218(or the absence of such a depression). RODS216may be configured in this manner by hardware changes, including by changes to the radio wave transmitting and receiving elements within RODS216, and/or by changing how the sensed data is analyzed via the processor in RODS216. RODS216is configured to detect objects within area118in the same manner as RODS116, but additionally analyzes the reflected radio waves to determine whether a ground surface is sensed where area118intersects the ground surface, or within area218. If a ground surface is not detected, or detected at a distance greater than a threshold setting, RODS216communicates to controller112that a depression is detected below and rearward of upper chassis104. Similar to RODS116, the radio wave transmitter and radio wave receiver of RODS216may both be included in a transceiver, a component capable of transmitting and receiving radio waves.

For example, RODS216may be configured to detect an object if the reflected radio waves result in a signal above a threshold signal strength, the threshold indicative of the expected return signal when no object is present and the radio waves reflect off a ground surface where area118meets area218. This expected return signal may also be referred to as a baseline. In alternative embodiments, the baseline may not be indicative of a particular signal strength, but may instead be indicative of other qualities of the expected return signal such as frequency, distribution, phase, or timing. In the embodiment illustrated inFIGS. 3-5, if the signal falls below the threshold signal strength, RODS216may indicate that a depression exists. RODS216may be programmed to require the signal strength to vary from the threshold by an amount, which may be pre-set or adjustable, before an indication of either an object or a depression is communicated, thereby changing the size of objects or depressions necessary to trigger RODS216. By analyzing the reflected radio waves to determine whether the expected signature of the ground surface is present, and present at the expected distance, RODS216may be utilized as a multi-use detection system capable of detecting both objects in area118and ground surface depressions in area218without the need for additional hardware.

RODS216may be configured such that it communicates a detected depression to controller112only when it detects a depression of sufficient volume, surface area, depth, or some combination of these and other factors. In alternative embodiments, RODS216may communication further information such as the size or distance of the detected depression, to enable controller112to take different actions based on the size or distance of the detected depression.

FIG. 6is a flowchart of control system300of enabling object and depression chimes and displaying object and depression notifications on work vehicle200equipped with RODS216. In step302, controller112receives a signal from RODS216. In step304, controller112determines whether the signal received in step302indicates that an object is behind work vehicle200. For example, RODS216may communicate a message on a Controller-Area Network (CAN) which indicates a normal status, an object status, or a depression status, and this message may be received on the CAN by controller112.

If controller112determines that the signal indicates an object is behind work vehicle200, it may proceed to step306, in which it determines whether work vehicle200is in a reverse mode. Controller112may determine whether work vehicle200is in a reverse mode by a number of different methods. For example, it may keep track of the state of work vehicle200and change states when it receives certain inputs from an operator in operator station108such as a shift from forward to reverse or a depression of a reverse throttle pedal. As another example, it may determine whether work vehicle200is in a reverse mode by monitoring a message from a Transmission Control Unit (TCU) which broadcasts the current state of the transmission of work vehicle200. As yet another example, it may determine whether work vehicle200is in a reverse mode by monitoring the pressure or flow delivered to hydraulic motors which drive ground-engaging devices106. For work vehicle200, controller112determines whether the vehicle is in a reverse mode by receiving a signal from sensor assembly110indicating the position of lower chassis102relative to upper chassis104, and receiving a signal from operator station108indicating the direction that the operator is commanding for ground-engaging devices106. Using both of these as inputs, controller112determines whether the operator's command will result in operator station108moving in rearward direction108band thus whether work vehicle200is in a reverse mode. If work vehicle200is not in a reverse mode, step308is performed next, and any current object or depression chimes or notifications are disabled.

If work vehicle200is in a reverse mode, step310is performed next. In step310, controller112enables an object chime. This object chime may take multiple forms. In control system300, a specific chime may be sounded by a speaker in operator station108, for example a repeating tone, or beeping, which indicates to the operator that an object has been detected behind work vehicle200by RODS216. In alternative embodiments, the object chime may vary depending on the distance or size of the object detected by RODS216, for example with the object chime growing louder or with shorter intervals between beeps for objects which are larger or closer. Step312is performed next, with controller112communicating with operator display114to display an object notification. This message may take many forms. In the embodiment disclosed inFIG. 6, the notification may be displayed text of the form “Object detected behind vehicle.” In alternative embodiments, the text may vary or the notification may include non-text components, such as highlighting or other coloring of the detected object on a video feed from a camera placed to view behind work vehicle200. After step312, controller112returns to the beginning of the loop with step302.

If the signal from RODS216is not determined to indicate an object behind work vehicle200in step304, then step314is performed next. In step314, any pre-existing object chime or object notification is disabled as no object has been detected, and step316is performed next. In step316, controller112determines whether the signal from RODS216indicates a depression behind work vehicle200. If not, controller112performs step308next, after which controller112returns to step302.

If a depression is detected behind work vehicle200, step318is performed next and controller112determines whether work vehicle200is in a reverse mode. Similar to step306, controller112may determine whether work vehicle200is in a reverse mode by monitoring the state of work vehicle200, messages from a TCU, inputs from an operator in operator station108, or monitoring flows and pressures to drive components for ground-engaging devices106. If work vehicle200is not in a reverse mode, step308is performed next, after which controller112returns to step302. If work vehicle200is in a reverse mode, step320is performed next.

In step320, controller112enables a depression chime. Similar to the object chime, the depression chime may take multiple forms. In control system300, a specific chime which is different than the object chime may be sounded by a speaker in operator station108, for example a repeating tone, or beeping, which is of a different tone, frequency, intensity, or character than the object chime, may be sounded by a speaker in operator station108. Similar to the object chime, the depression chime may be varied to indicate the distance to, or size of, the detected depression, including by growing louder or more frequent as the distance to the detected depression is decreased or the size of the detected depression is increased.

In step320, controller112or RODS216may optionally analyze the sensed radio waves to determine characteristics of the depression on the ground surface in the area218and enable the depression chime based on these characteristics. As one example, controller112may analyze a message received from RODS216indicative of the size of a depression in the area218. Controller112may enable the depression chime only when the size (e.g., width, depth, volume) indicated by the message is greater than a threshold, and the threshold may be preset, operator adjustable, or set based on a feature of the work vehicle200such as a dimension of a ground-engaging device106(e.g., length). In this way, controller112may vary whether the depression chime is enabled depending on the size of the depression relative to the size of a feature of work vehicle200. As another example, RODS216may analyze the sensed radio waves to determine the position of the depression relative to ground-engaging devices106and may communicate a positive indication of a depression to controller112only when the depression is determined to be within the expected path of at least one of ground-engaging devices106.

Step322is performed next, with controller112communicating with operator display114to display a depression notification. This message may take many forms, including displayed text, such as of the form “Depression detected behind vehicle.” In alternative embodiments, the text may vary or the notification may include non-text components, such as highlighting or a zoomed-in view of the detected depression on a video feed from a camera placed to view behind work vehicle200. After step322, controller112returns to the beginning of the loop with step302.

After step322, controller112may optionally derate work vehicle200based on a communication from RODS216. For example, controller112may derate (e.g., limit the maximum speed, acceleration, or power of) work vehicle200or force work vehicle200to stop if RODS216communicates the presence of an object or a depression within a certain distance of one of ground-engaging devices106or upper chassis104. As another example, controller112may derate work vehicle200if RODS216indicates the presence of a depression positioned in the path of one of ground-engaging devices106, and may eventually prevent further movement of ground-engaging devices106toward the depression if the depression is close enough to one of ground-engaging devices106.

AlthoughFIG. 6is illustrated as a flowchart, the disclosure is not limited to such steps and the order of steps presented, and it would be well within the skill of one of ordinary skill in the art to reorder, combine, or split many of the steps and achieve the same result.

In alternative embodiments, when both an object and a depression are detected, controller112may be configured to operate differently than the embodiment illustrated inFIG. 6. For example, controller112may be configured to enable the depression chime and display the depression notification when both an object and a depression are detected. As another example, controller112may be configured to enable both the object and depression chimes and display both the object and depression notifications. As yet another example, the chimes and notifications may be the same for both objects and depressions, simplifying control system300down to enabling the chime or notification is either an object or depression is detected.

While the disclosure has been illustrated and described in detail in the drawings and foregoing description, such illustration and description is not restrictive in character, it being understood that illustrative embodiment(s) have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected. Alternative embodiments of the present disclosure may not include all of the features described yet still benefit from at least some of the advantages of such features. Those of ordinary skill in the art may devise their own implementations that incorporate one or more of the features of the present disclosure and fall within the spirit and scope of the appended claims.