Patent Description:
Warehouses typically employ the use of multiple material handling vehicles, specifically, operators may control travel of a material handling vehicle within the warehouse and navigate around obstacles, including other active material handling vehicles.

For certain types of vehicles that are manually operated, there are training requirements imposed by various government agencies, laws, rules and regulations. For example, the United States Department of Labor Occupational Safety and Health Administration (OSHA) imposes a duty on employers to train and supervise operators of various types of material handling vehicles. Recertification every three years is also required. In certain instances, refresher training in relevant topics shall be provided to the operator when required. In all instances, the operator remains in control of the material handling vehicle during performance of any actions. Further, a warehouse manager remains in control of the fleet of material handling vehicles within the warehouse environment.

One prior art document is <CIT>, that discloses an electronic systems that collect information related to the operation and movement of electronic badges in industrial applications. Another prior art document is <CIT>, that discloses a method and apparatus for avoiding collisions of moving vehicles using a position and motion location system to track vehicle location and motion. A further prior art document is <CIT>, that discloses a method an apparatus for avoiding collisions of moving vehicles in an environment that utilizes a position and rotational orientation system to track vehicle locations.

The present invention relates generally to vehicle awareness and, more specifically, to vehicle awareness systems and methods for use in conjunction with a material handling vehicle operated in a warehouse environment.

In one aspect, the present invention provides a system for vehicle-to-vehicle communication between a first material handling vehicle and a second material handling vehicle. The system includes a first material handling vehicle including a wireless transceiver configured to send and receive vehicle condition data, a speed sensor configured to detect a speed of the material handling vehicle, a steering angle sensor configured to detect a steering angle of a traction wheel, a position sensor configured to detect a position of the material handling vehicle, and a control unit in communication with the wireless transceiver, the speed sensor, the steering angle sensor, and the position sensor. The control unit is configured to receive a vehicle condition data, via the wireless transceiver, from a second material handling vehicle within a predetermined communication range of the wireless transceiver, calculate a first predicted vehicle position for the first material handling vehicle based on current vehicle condition data, calculate a second predicted vehicle position for the second material handling vehicle based on the received vehicle condition data, and determine if the first predicted vehicle position and the second predicted vehicle position overlap.

According to another aspect of the present invention, a method of controlling a material handling vehicle is provided. The method includes receiving vehicle condition data at a first material handling vehicle from a second material handling vehicle when the second material handling vehicle is within a predetermined communication range, determining a first predicted vehicle position for the first material handling vehicle based on current vehicle conditions, determining a second predicted vehicle position for the second material handling vehicle based on the received vehicle condition data, and determining if the first predicted vehicle position for the first material handling vehicle overlaps with the second predicted vehicle position for the second material handling vehicle. Upon the determination that the first predicted vehicle position overlaps with the second predicted vehicle position, the operator of the first material handling vehicle is provided an indication.

According to another aspect which is not part of the present invention, a system for assisting an operator of a material handling vehicle can include a first material handling vehicle. A transceiver can be configured to receive a condition data of a second material handling vehicle. A speed sensor can be configured to measure a speed of the first material handling vehicle. A steering angle sensor can be configured to measure a steering angle of the first material handling vehicle. The system can include an operator indicator. A control unit can be configured to calculate at least a first predicted path of the first material handling vehicle based at least in part on the speed of the first material handling vehicle received from the speed sensor and the steering angle of the first material handling vehicle received from the steering angle sensor. The control unit can receive, from the transceiver, the condition data. The control unit can calculate, using the condition data, a second predicted path of the second material handling vehicle. The control unit can determine if the first predicted path overlaps with the second predicted path. When the first predicted path overlaps with the second predicted path, the control unit can provide an indication to the operator.

The foregoing and other aspects and advantages of the invention will appear from the following description. In the description, reference is made to the accompanying drawings which form a part hereof, and in which there is shown by way of illustration a preferred configuration of the disclosure. Such configuration does not necessarily represent the full scope of the disclosure, however, and reference is made therefore to the claims and herein for interpreting the scope of the disclosure.

Before any aspects of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other aspects and of being practiced or of being carried out in various ways.

The following discussion is presented to enable a person skilled in the art to make and use embodiments of the invention. Various modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the generic principles herein can be applied to other embodiments and applications without departing from the scope of the claims. Thus, embodiments of the invention are not intended to be limited to embodiments shown, but are to be accorded the widest scope of the features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the claims. Skilled artisans will recognize the examples provided herein have many useful alternatives and fall within the scope of the claims.

It is also to be appreciated that material handling vehicles ("MHVs") are designed in a variety of classes and configurations to perform a variety of tasks. It will be apparent to those of skill in the art that the present disclosure is not limited to any specific MHV, and can also be provided with various other types of MHV classes and configurations, including for example, lift trucks, forklift trucks, reach trucks, SWING REACH® vehicles, turret trucks, side loader trucks, counterbalanced lift trucks, pallet stacker trucks, order pickers, transtackers, and man-up trucks, and can be commonly found in warehouses, factories, shipping yards, and, generally, wherever pallets, large packages, or loads of goods can be required to be transported from place to place. The various systems and methods disclosed herein are suitable for any of operator controlled, pedestrian controlled, remotely controlled, and autonomously controlled material handling vehicles.

In a conventional warehouse environment, methods of maintaining awareness of other nearby MHVs and their trajectories rely primarily on operators of the MHVs visually observing other vehicles and mentally predicting the vehicle's trajectory or intentions. To augment vehicle awareness, the use of a horn, floor spotlight, or continuous hazard lights are used.

According to aspects of the present disclosure, MHVs (e.g., manually driven or automated MHVs) can communicate their current position, speed, and trajectory to other nearby MHVs via a wireless vehicle-to-vehicle communication methods. This data communicates to other vehicles a predicted vehicle path that the MHV is currently occupying and/or including a load, or a predicted vehicle path that the MHV will soon be occupy in the immediate future. Nearby MHVs compare a predicted vehicle path that they plan to occupy based on their own position, speed, and trajectory with the predicted vehicle path claimed by all other MHVs within a predetermined communication range. If a vehicle calculates that its predicted vehicle path overlaps with the path already claimed (or predicted) by another MHV, a notification can be delivered to the operator of the MHV, or command the MHV to perform some other action, for example, to initiate slowing the MHV or denying a drive command given by the operator. In this way the operator is provided the ability to be made aware of other vehicles working nearby without direct line of sight to the other vehicles.

<FIG> and <FIG> illustrate one non-limiting example of a material handling vehicle <NUM> according to the present disclosure. The material handling vehicle <NUM> may include a vehicle frame <NUM>, a steerable traction wheel <NUM>, a fixed axle <NUM>, a power section <NUM>, and an operator compartment <NUM>. The power section <NUM> may be disposed within the vehicle frame <NUM> and may include a battery (or other power source) configured to supply power to various components of the material handling vehicle <NUM>. For example, a battery may supply power to a motor (not shown) and/or transmission (not shown) disposed within the power section <NUM> and configured to drive the traction wheel <NUM>. In the illustrated non-limiting example, the traction wheel <NUM> is arranged under the power section <NUM>. In other non-limiting examples, the traction wheel <NUM> may be arranged in another location under the vehicle frame <NUM>.

The operator compartment <NUM> may include a control handle <NUM> configured to provide a user interface for an operator and to allow the operator to control a speed and direction of travel of the material handling vehicle <NUM>. In some non-limiting examples, the control handle <NUM> may be configured to manually steer and control power to the traction wheel <NUM>. In the illustrated non-limiting example shown in <FIG> and <FIG>, the material handling vehicle <NUM> includes a pair of forks <NUM> configured to engage loads (e.g., a pallet). The forks <NUM> can be raised and lowered by an actuator (not shown) to lift/place loads. In some non-limiting examples, forks can be coupled to a mast and be raised or lowered via actuators in response to commands from a control handle.

The MHV <NUM> can be operated by an operator and can be capable of picking, placing, transporting, or otherwise manipulating a load, possibly including a pallet. In various examples, the operator controls the MHV <NUM> so that the forks <NUM> engage a pallet carrying a load. In so doing, the operator may extend or retract actuators (not shown) to pick, place, engage, or otherwise manipulate the load. Once the load is situated on the forks <NUM>, the operator can move the load to another location as needed. In some non-limiting examples, a human operator may be replaced with an automated controller to comprise a fully automated system (i.e., an autonomously guided material handling vehicle).

<FIG> illustrates a control system <NUM> for the MHV <NUM>. As will be described, the control system <NUM> can communicate via wireless communication with one or more MHVs 10a, 10b through a transceiver <NUM>. The communication may occur through one or more of any desired combination of wireless communication mechanisms and any desired network topology (or topologies when multiple communication mechanisms are utilized). Exemplary wireless communication networks include a <NUM> networks, a BLUETOOTH module, and/or a Wi-Fi transceiver, among others, including the Internet, cellular, satellite, microwave, and radio frequency, for providing data communication between MHVs <NUM>, 10a, and 10b. It is to be understood that, while only one MHV control system is illustrated in detail in <FIG>, each MHV (e.g., MHV 10a, 10b) would each include an identical control system. Further, although <FIG> illustrates two MHVs 10a, 10b in communication with MHV <NUM>, it is to be understood that the MHV <NUM> can be in communication with a plurality of MHVs.

In the illustrated non-limiting example, the MHV <NUM> can include a control unit <NUM> in communication with the transceiver <NUM>. The control unit <NUM> can include a processor <NUM> for processing and executing instructions stored in a memory <NUM>. It should be appreciated that the control unit <NUM> may be a stand-alone dedicated controller or integrated within a larger control system within the MHV. It should also be appreciated that the control unit <NUM> can include more than one processor <NUM>.

The MHV <NUM> also includes a positioning system <NUM> including a positioning device <NUM>, such as a real time location system ("RTLS") and/or a global positioning system ("GPS"), in communication with the control unit <NUM>. The positioning device <NUM> can be configured to detect a position or location of the MHV <NUM> within an operating environment (e.g., a warehouse, storage yard, etc.) and report that location to the control unit <NUM>. For example, the positioning device <NUM> can provide the control unit <NUM> with a coordinate location for the MHV <NUM>. The positioning system <NUM> can also include one or more gyroscopes <NUM>, and/or one or more accelerometers <NUM> to measure the position, orientation, direction, speed, and acceleration of the MHV <NUM>.

In the illustrated non-limiting example, the control unit <NUM> can be in communication with a variety of vehicle equipment. For example, the control unit <NUM> can be in communication with a steering system <NUM> of the MHV <NUM> to detect a position of the steerable traction wheel <NUM> and/or provide steering commands to the steerable traction wheel <NUM>. For example, the steering system <NUM> can include a steering angle sensor <NUM> configured to detect a steering angle of the traction wheel <NUM> and/or steering angle input on the control handle <NUM>. According to some non-limiting examples, the MHV <NUM> can be a four-wheeled vehicle including two steerable wheels. In this case, the steering angle can be determined as an average steer angle of the two steerable wheels.

According to some non-limiting examples, the control unit <NUM> can be in communication with a vehicle speed sensor <NUM> configured to detect a speed of the MHV <NUM>. For example, the speed sensor <NUM> can be configured to detect a wheel speed of the MHV <NUM>. The control unit <NUM> can be in communication with a drive system <NUM>. The drive system <NUM> may provide a motive force for moving the MHV <NUM> in a designated travel direction, for example, by driving the traction wheel <NUM> of the MHV <NUM>. The control unit <NUM> can receive drive commands via the drive system <NUM>, for example, via an operator input to the control handle <NUM>, and evaluate those drive commands in accordance with the methods described herein. The control unit <NUM> can also be in communication with a brake control system <NUM>, which can include a brake configured to slow or stop the MHV <NUM>. The control unit <NUM> can be configured to deliver a stop command to the vehicle brake control system <NUM> to stop the MHV <NUM> in response to an operator input to the control handle <NUM> or other form of vehicle brake control device.

According to the illustrated non-limiting example, the control unit <NUM> can be in communication with one or more operator indicators <NUM>, which may prompt visual, auditory, and/or tactile indications if certain conditions are determined, as will be described herein. For example, one or more light sources on the MHV <NUM> or indications on a vehicle display can provide a visual indication. According to some non-limiting examples, a vehicle horn and/or a speaker may provide an audible indication. In other non-limiting examples, a tactile or haptic indication can be provided as a vibration to the operator through the control handle <NUM>, or any other portion of the material handling vehicle <NUM> that can be in contact with the operator.

Referring now to <FIG>, a method <NUM> of augmenting vehicle awareness for an operator of an MHV is illustrated. The method <NUM> can begin at block <NUM>, where a first MHV 10a (see, e.g., <FIG>) can be continuously monitoring for MHVs nearby within a predetermined communication range 132a via the transceiver <NUM> arranged on the MHV 10a (see <FIG>). Similarly, the first MHV 10a is within a predetermined communication range 132b of the second MHV 10b. According to some non-limiting examples, the predetermined communication range can be defined by a radius around the MHV that is at least twice the maximum stopping distance for the MHV. In the following description, the method <NUM> will be described from the perspective of the first MHV 10a.

While the first MHV 10a and the second MHV 10b are within communication range of each other, vehicle condition data can be sent and received by the transceiver <NUM> on the corresponding MHV 10a, 10b. At block <NUM>, the first MHV 10a can receive the vehicle condition data from the second MHV 10b for processing and evaluation by the control unit <NUM> (see <FIG>). The vehicle condition data for the second MHV 10b can include a pre-calculated predicted vehicle path for the second MHV 10b and/or a position (e.g., two-dimensional coordinates of the MHV within a warehouse, a GPS location, etc.), speed, and steering angle (e.g., from the speed sensor <NUM> and the steering angle sensor <NUM>, respectively) for the second MHV 10b.

The first MHV 10a, via the control unit <NUM>, can then calculate predicted positions or position information for the first and second MVHs 10a, 10b, based on the vehicle condition data of the first MHV 10a and the received vehicle condition data from the second MHV 10b. As shown in <FIG>, the predicted position information can be a first predicted vehicle path 134a for the first MHV 10a and a second predicted vehicle path 134b for the second MHV. For example, each MHV 10a, 10b can store (e.g., in the memory <NUM>) a map or coordinate space of the operating environment. As illustrated in <FIG>, a second MHV 10b is within the predetermined communication range 132a of the first MHV 10a. The first MHV 10a can update the map of the operating environment within the memory <NUM> with the calculated predicted vehicle paths for the first MHV 10a and the second MHV 10b. With the predicted vehicle paths 134a, 134b calculated, the first MHV 10a can determine if the predicted vehicle paths 134a, 134b overlap/intersect at block <NUM>. For example, as illustrated in <FIG>, the predicted vehicle paths 134a, 134b do not overlap. In this case, the first MHV 10a would return to block <NUM> and continue to monitor for MHVs within its predetermined communication range 132a.

Alternatively, as illustrated in <FIG>, the predicted vehicle paths 134a, 134b overlap, and the method <NUM> illustrated in <FIG> can provide an indication to the operator at block <NUM>. In this case, the first MHV 10a provides an indication 136a to the operator, for example, via the operator indicator <NUM> (see <FIG>) indicating to the operator that the second MHV 10b, which may or may not be within a line of sight of the operator, is approaching to increase the awareness of the operator. It is to be understood that the second MHV 10b is also continuously executing the method <NUM>, and likewise, would provide an indication 136b to the operator of the second MHV 10b.

According to another non-limiting example, the method <NUM> can be applied in situations where a drive command is being given by an operator of a MHV and the MHV can calculate a predicted vehicle path based on the received drive command and prior to the control unit <NUM> executing the received drive command. For example, as illustrated in <FIG>, the first MHV 10a is traveling along while the second MHV 10b is stationary. As a result, the predicted vehicle path 134a of the first MHV 10a projecting forward from the first MHV 10a along the direction of travel is larger than the area occupied by the second MHV 10b. As illustrated, the stationary second MHV 10b is located at an end of an aisle, resulting in a predicted vehicle path 134b correlating to the area occupied by the MHV 10b.

As illustrated in <FIG>, when the control unit <NUM> of the second MHV 10b receives a drive command from the operator (e.g., via the control handle <NUM> or other input device), the control unit <NUM> can calculate an estimated vehicle path 138b based on the driver command and execute the method <NUM> based on that estimated vehicle path 138b. That is, with the first MHV 10a and the second MHV 10b within communication range 132a, 132b of each other, vehicle condition data, including the estimated vehicle path 138b, can be sent and received therebetween. The second MHV 10b can receive vehicle condition data from the first MHV 10a for evaluation. The second MHV 10b, via the control unit <NUM>, can then calculate a predicted vehicle path 134a for the first MHV 10a and compare that predicted vehicle path 134a with the estimated vehicle path 138b. With the vehicle paths calculated, the second MHV 10b can determine if the vehicle paths 134a, 138b overlap/intersect. For example, as illustrated in <FIG>, the vehicle paths 134a, 138b overlap. In this case, the second MHV 10b provides an indication 136b to the operator, indicating to the operator that the first MHV 10a is approaching to increase the awareness of the operator. It is to be understood that the first MHV 10a can also receive the calculated estimated vehicle path 138b from the second MHV 10b, and execute method <NUM> to provide an indication to the operator.

According to some non-limiting examples, the control unit <NUM> can intercept the drive command and determine to execute that command dependent upon the determination that the predicted or estimated vehicle paths overlap. For example, the control unit <NUM> can receive a drive command and, upon the determination that the estimated path 138b of the second MHV 10b overlaps with the predicted vehicle path 134a of the first MHV 10a, prevent the drive system <NUM> from executing the drive command. According to some non-limiting examples, the control unit <NUM> can be configured to activate the brake via the vehicle brake control system <NUM>, or deactivate the drive system <NUM>, upon the detection of overlapping predicted vehicle paths. In other non-limiting examples, the control unit <NUM> can alter the drive command to a different value. For example, travel of the MHV can be allowed in the specified direction at a reduced speed, for which the vehicle paths of the MHV and other MHVs in proximity do not overlap.

Referring now to <FIG>, a method of calculating a predicted vehicle path will be described. According to the illustrated non-limiting example, the predicted vehicle path can be a two-dimensional planar area including the footprint of the MHV <NUM>, along with any loads received thereon, and an estimation of the area to be occupied by the MHV <NUM> in the immediate future based on the current vehicle conditions (e.g., position, speed, steering angle, etc.). For example, given a vehicle's geometry (footprint, wheelbase, position of steered tire, etc.) it is possible to calculate an estimated path the vehicle will travel (i.e., predicted vehicle path). Accounting for the speed and/or stopping distance of the MHV <NUM>, given current vehicle conditions, the floor area the vehicle has a high probability of occupying in the immediate future can be calculated. In the following description, a two-dimensional example of calculating a predicted vehicle path is described, although it is to be understood that calculating a three-dimensional example is within the capability of those skilled in the art.

Referring to <FIG>, the geometry of the MHV <NUM> can be defined by a bounding box <NUM> surrounding the outer periphery of the MHV <NUM>. In the illustrated non-limiting example, the bounding box <NUM> is defined by the rectangular area between point A at the front left of the MHV <NUM>, point B at the front right of the MHV <NUM>, point E at the rear left of the MHV <NUM>, and point D at the rear right of the MHV <NUM>. The MHV <NUM> can also define an axle axis <NUM> and a turning axis <NUM>. The axle axis <NUM> can be defined by a line passing through the fixed axle <NUM> of the MHV <NUM> and the turning axis <NUM> can be defined by an axis passing through the center of the steerable traction wheel <NUM>, orthogonal to the direction of the traction wheel <NUM>. An origin <NUM> for the MHV <NUM>, for the purposes of the calculation below, at the orthogonal projection of the center of the steerable traction wheel <NUM> onto the axle axis <NUM>, defined along the fixed axle <NUM>, with the steerable traction wheel in a neutral (e.g., straight) position. As the MHV <NUM> begins to steer, a turning center <NUM> can be defined as the intersection between the axle axis <NUM> and the turning axis <NUM>.

A predicted vehicle path of a material handling vehicle can be a composite or combination of the areas of a bounding box of the MHV at a first location, a bounding box of the MHV at a predicted stopping location, and a plurality of annulus areas that extend therebetween. In this regard, <FIG> illustrates an exemplary predicted vehicle path <NUM> calculated for a MHV <NUM> executing a left turn. This area can be approximated by employing the following calculations. First, the bounding box <NUM> defined by the geometry of the MHV <NUM> can be calculated (<FIG>) at a current position of the MHV <NUM>. Then, a bounding box <NUM>' at a predicted location of the MHV <NUM> can be calculated. According to one non-limiting example, the predicted location can be determined by the distance the MHV <NUM> will travel prior to being able to come to a stop based on the current vehicle conditions. The bounding box <NUM>' can be calculated by revolving each of the points A, B, C, D of bounding box <NUM> about the turning center <NUM> by a revolving angle ϕ, resulting in the bounding box <NUM>' defined by points A', B', C', D'. According to one non-limiting example, the revolving angle ϕ can be determined by setting the traction wheel <NUM> arc length equal to the stopping distance based on the current vehicle conditions.

Then, referring to <FIG>, a first, second, and third annulus areas can be calculated. The annulus areas are configured to account for the portions of the MHV <NUM> that turn at different radii depending on their location relative to the traction wheel <NUM>. Referring specifically to <FIG>, the first annulus area <NUM> can be defined by forming an annulus sector by sweeping about the turning center <NUM> by the revolving angle ϕ along an inner radius defined by the distance between the turning center <NUM> and point F (where the edge of the bounding box <NUM> intersects with the axle axis <NUM>, see <FIG>) and an outer radius defined by the distance between the turning center <NUM> and the origin <NUM>. It is to be understood that, in the case of a right hand turn, point C would be utilized (see <FIG>) instead of point F, and the turning center <NUM> would be arranged on the right hand side of the MHV <NUM>.

Referring now to <FIG>, the second annulus area <NUM> can be defined by forming an annulus sector by sweeping about the turning center <NUM> by the revolving angle ϕ along an inner radius defined by the distance between the turning center <NUM> and the origin <NUM> and an outer radius defined by the distance between the turning center <NUM> and point B. It is to be understood that, in the case of a right hand turn, point A would be utilized (see <FIG>) instead of point B, and the turning center <NUM> would be arranged on the right hand side of the MHV <NUM>.

Referring now to <FIG>, the third annulus area <NUM> can be defined by forming an annulus sector by sweeping about the turning center <NUM> by the revolving angle ϕ along an inner radius defined by the distance between the turning center <NUM> and the origin <NUM> and an outer radius defined by the distance between the turning center <NUM> and point D. It is to be understood that, in the case of a right hand turn, point E would be utilized (see <FIG>) instead of point D, and the turning center <NUM> would be arranged on the right hand side of the MHV <NUM>.

Referring back to <FIG>, the predicted vehicle path <NUM> can be defined by an overlay of the bounding box <NUM> for the MHV <NUM> at its current position, the bounding box <NUM>' of the MHV <NUM> at its predicted location, and the first, second, and third annulus areas <NUM>, <NUM>, <NUM>. According to some non-limiting examples, the predicted vehicle path <NUM> can be calculated in a first MHV and then delivered as an output to a second MHV. According to some non-limiting examples, the predicted vehicle path <NUM> can be calculated by a first MHV based on vehicle condition data delivered from a second MHV.

In other embodiments, as illustrated in <FIG>, an example method <NUM> of augmenting vehicle awareness for an operator of an MHV can be utilized. At block <NUM>, as at block <NUM> of the method <NUM>, the first MHV 10a can be continuously monitoring for MHVs nearby within a predetermined communication range 132a via the transceiver <NUM> arranged on the MHV 10a (see <FIG>). At block <NUM>, the first MHV 10a can receive the vehicle condition data from the second MHV 10b for processing and evaluation by the control unit <NUM> (see <FIG>). Additionally or alternatively to the vehicle condition data described with respect to block <NUM> of the method <NUM>, the vehicle condition data for the second MHV 10b can include a list of pre-calculated possible vehicle positions at set points in time in the future for the second MHV 10b, and/or maximum and minimum values for acceleration and steer angles. Alternatively, the material handling vehicle 10a could receive data about the dynamic conditions of vehicle 10b (e.g., current speed, dimensions, weight, steer angle, etc.), and could generate one or more precalculated possible vehicle positions of the second MHV 20b.

At block <NUM>, the method <NUM> can determine possible future positions of the first MHV 10a and the second MHV 10b at set time points in time or time intervals, based on the vehicle condition data received at block <NUM>. The possible future positions can include multiple possible positions for one or both of the MHVs 10a, 10b for different dynamic conditions of the respective MHV (e.g., steer angle changes, acceleration, deceleration).

Referring now to <FIG>, an envelope <NUM> for future possible vehicle positions is shown at a time t for MHV <NUM>. The envelope <NUM> can define an area which can include an overlay of a plurality of possible positions for the MHV <NUM> at time t, assuming different dynamic conditions. For example, the envelope <NUM> can include an area for a first possible position <NUM> of the MHV <NUM>, which as illustrated is the position the MHV <NUM> would occupy at time t if travelling at a maximum leftward steering angle, and a maximum deceleration. The envelope could also include an area for a second possible position <NUM> of the MHV, which is the position MHV would occupy at time t if travelling at a maximum rightward steering angle and a maximum deceleration for time t. The envelope could further include a third possible position <NUM> which assumes a maximum acceleration and maximum rightward steering angle at time t, and a fourth possible position <NUM> which assumes a maximum acceleration and maximum leftward steering angle of the MHV at time t. In other non-limiting examples, the envelope can also include possible positions for the MHV when travelling at other steering angles or accelerations, including a possible position for the MHV <NUM> when travelling at a maximum acceleration with a <NUM> degree steering angle, and/or a possible position for the MHV <NUM> when travelling at a maximum deceleration at a <NUM> degree steering angle. Thus, for a given future point in time, and envelope <NUM> can include or encompass all possible positions for the MHV at the given time, or a subset of possible positions, given different dynamic conditions. A plurality of envelopes <NUM> can be calculated for each MHV <NUM>, 10a, 10b, for a plurality of corresponding points in time. In some non-limiting examples, an envelope for a future possible position can be calculated for every <NUM> seconds up to <NUM> seconds (e.g., a future position can be calculated at <NUM>, <NUM>, <NUM>, s, <NUM>, etc.). In some embodiments, future positions can be calculated at about <NUM> second intervals, or <NUM> second intervals, or <NUM> second intervals. In some embodiments, a stopping time can be calculated, based on the time it would require for an MHV to come to a full stop at a maximum deceleration, and this stopping time can define an ultimate time for which a possible future position is calculated. For example, if a stopping time for a material handling vehicle is <NUM> seconds, the future positions of the material handling vehicle can be calculated up to <NUM> seconds. In some embodiments, the maximum time for which a future position is calculated can be a setting that is set by a user of the material handling vehicle.

It is to be understood that calculating an envelope for future possible positions can take into account a current position, velocity, trajectory, steering angle, or acceleration of the material handling vehicle. Additionally, the possible future positions, and envelopes containing these possible future positions can be predicted based on a drive command from the operator of the MHV, as discussed, for example, with respect to <FIG> and <FIG>.

Referring back to <FIG>, at block <NUM>, the example method <NUM> can include a determination of whether a possible future position of the second MHV 10b at a given time overlaps with a corresponding possible future position of the first MHV 10a at the same point in time. In this regard, <FIG> illustrate a non-limiting example showing initial positions 140a, 140b, and calculation of envelopes 160a, 160b for the first MHV 10a and the second MHV 10b. As shown in the non-limiting example in <FIG>, at an initial time t<NUM>, the first MHV 10a is travelling rightward and the second MHV 10b is traveling in a direction towards the initial position 140a of MHV 10a (e.g., MHV 10a is in a path of travel of MHV 10b). A calculation is performed at <FIG> for envelopes 160a, 160b of future possible positions of MHVs 10a and 10b at time t<NUM>. It is to be understood that either or both of the MHVs 10a, 10b can perform this calculation based on the condition data received. As shown, the envelope 160b for a possible future position of the second MHV 10b at time t<NUM> overlaps with the first MHV 10a at the first MHV 10a initial position (e.g., initial position 140a). However, because the envelope 160b does not overlap with envelope 160a at time t<NUM>, no indication is provided to the operator at step <NUM>, as the possible future positions of the MHVs 10a, 10b at time t<NUM> do not intersect or overlap. <FIG> illustrate envelopes 160a, 160b for future possible positions of MHVs 10a, 10b respectively at time t<NUM>. The method <NUM> can determine if the envelopes 160a, 160b intersect at t<NUM> simultaneously to making that determination for t<NUM>, and thus the method could not only identify a potential overlap or intersection, but also a potential timing of the intersection, and could provide that additional information to the operator or to the control unit <NUM> to take an appropriate action in response thereto. As shown, the future possible positions represented by envelopes 160a, 160b at t<NUM> do not overlap, and therefore, no indication is provided to the operator at step <NUM>.

<FIG> illustrates another non-limiting example showing the operation of method <NUM> for MHVs 10a, 10b. In the illustrated example, an envelope 160a is calculated for possible future positions of MHV 10a at time tn, and an envelope 160b is calculated for possible future positions of MHV 10b at time tn. As shown, the envelopes 160a, 160b overlap, and therefore at step <NUM> (see <FIG>), an indicator can be provided to the operator of either or both of MHVs 10a, 10b.

The present disclosure provides distinct advantages, such as the ability to provide an indication to operators that other MHVs are nearby, without the need for line of sight, increasing the vehicle awareness of the operator. Further, the systems and methods described herein can selectively notifying operators when the predicted vehicle path of their MHV overlap with that of another MHV's predicted vehicle path. In addition, the present disclosure provides systems and methods for evaluating an operator's drive commands, and evaluate that command based on environmental conditions, such as the vehicle conditions of nearby MHVs, before executing the drive command.

While various spatial and directional terms, such as top, bottom, lower, mid, lateral, horizontal, vertical, front, and the like may be used to describe examples of the present disclosure, it is understood that such terms are merely used with respect to the orientations shown in the drawings. The orientations may be inverted, rotated, or otherwise changed, such that an upper portion is a lower portion, and vice versa, horizontal becomes vertical, and the like.

Claim 1:
A system for vehicle-to-vehicle communication between a first material handling vehicle (10a) and a second material handling vehicle (10b), the system comprising:
a first material handling vehicle (10a) including a wireless transceiver (<NUM>) configured to send and receive vehicle condition data, a speed sensor (<NUM>) configured to detect a speed of the material handling vehicle (10a), a steering angle sensor (<NUM>) configured to detect a steering angle of a traction wheel (<NUM>), a position sensor (<NUM>) configured to detect a position of the material handling vehicle (10a), and a control unit (<NUM>) in communication with the wireless transceiver (<NUM>), the speed sensor (<NUM>), the steering angle sensor (<NUM>), and the position sensor (<NUM>), the control unit (<NUM>) configured to:
receive a vehicle condition data, via the wireless transceiver (<NUM>), from a second material handling vehicle (10b) within a predetermined communication range of the wireless transceiver (<NUM>);
calculate a first predicted vehicle position for the first material handling vehicle (10a) based on current vehicle condition data;
calculate a second predicted vehicle position for the second material handling vehicle (10b) based on the received vehicle condition data; and
determine if the first predicted vehicle position and the second predicted vehicle position overlap.