Patent Description:
There is a work vehicle including a boom that can be raised and laid down. The boom is laid down during traveling of the work vehicle, and a tip end portion of the boom protrudes forward from a front end of a vehicle body.

Patent Literature <NUM> discloses a vehicle equipped with a sensor that detects a front side of the vehicle, and a brake control system. The brake control system controls an operation of a brake of the vehicle in accordance with an obstacle in front of the vehicle detected by the sensor.

Patent Literature <NUM> discloses a safety device consisting of a lower travel body and an upper revolving superstructure rotatably mounted on the lower travel body. The upper revolving superstructure is provided with a boom body capable of freely rising and falling.

Patent Literature <NUM> discloses a crane that is provided with an obstacle sensor that, during travel, detects the approach of obstacles toward a front side part of a travel body and, during work, detects the approach of obstacles toward a rear side part of a turning body.

Patent Literature <NUM> discloses a surrounding display device for a traveling crane, whereby the positional relationship between surrounding objects and a boom can be easily understood.

The inventor of the present application notices that in a work vehicle including a boom, a problem that does not occur in a normal vehicle may occur. Specifically, there is a problem that when the work vehicle including a boom enters an intersection or the like without a traffic light for a left turn and a right turn, a driver of another vehicle travels straight from a lateral side without being aware of the boom protruding forward from a front end of a vehicle body of the work vehicle, and the other vehicle may come into contact with a tip end portion of the boom.

The present invention is made in consideration of the above circumstances, and has an object to provide a means capable of preventing another vehicle from coming into contact with a tip end portion of a boom at the time of entering an intersection or the like.

When it is determined that an obstacle in front of the vehicle body detected by the sensor, such as an elevated structure or a viaduct, is coming into contact with the boom, the controller drives the brake device to stop the vehicle body. Therefore, the work vehicle according to the present invention can also travel safely by preventing contact between an obstacle such as an elevated structure and the boom.

The work vehicle according to the present invention can prevent another vehicle from coming into contact with the tip end portion of the boom when entering an intersection or the like.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings as appropriate. The embodiments to be described below are merely one aspect of the present invention, and it is needless to say that the embodiments may be modified without departing from the scope of the present invention, defined by the claims.

<FIG> shows a crane vehicle <NUM> according to the present embodiment. The crane vehicle <NUM> is an example of a "work vehicle" according to the present invention. However, the work vehicle is not limited to the crane vehicle <NUM>. The work vehicle may include a boom such as a truck crane that can be laid down and whose tip end protrudes forward from a front end of a vehicle body during traveling.

The crane vehicle <NUM> mainly includes a traveling body <NUM>, and a crane device <NUM> and a cabin <NUM> that are mounted on the traveling body <NUM>.

The traveling body <NUM> includes a vehicle body <NUM>, an axle (not shown) and wheels <NUM>, an engine (not shown), a battery <NUM> (<FIG>), and a hydraulic device (not shown).

The axle is rotatably supported by the vehicle body <NUM>. The wheels <NUM> are held at both ends of the axle. The engine rotationally drives the axle, and rotates the wheels <NUM> via the axle. In addition, the engine charges the battery <NUM> (<FIG>). Furthermore, the engine drives a hydraulic pump provided in the hydraulic device. The hydraulic pump discharges hydraulic oil having a predetermined pressure to drive a swing motor or the like to be described later.

As shown in <FIG>, the vehicle body <NUM> includes a front outrigger <NUM> and a rear outrigger <NUM> that stabilize a posture of the vehicle body <NUM>.

The front outrigger <NUM> is provided at a front portion of the vehicle body <NUM>. The front outrigger <NUM> includes an outer cylinder, a pair of left and right inner cylinders, an outrigger cylinder, and a pair of right and left jack cylinders. The outer cylinder extends along a width direction of the vehicle body <NUM>. The inner cylinders are inserted into the outer cylinder, and are slidable in the width direction of the vehicle body <NUM>. The outrigger cylinder is supplied with the hydraulic oil by the hydraulic device and expands and contracts so as to slide the inner cylinders. The jack cylinders are fixed to tip ends of the inner cylinders, respectively. The jack cylinder is supplied with the hydraulic oil by the hydraulic device, and expands and contracts in a vertical direction.

The rear outrigger <NUM> is provided at a rear portion of the vehicle body <NUM>. The rear outrigger <NUM> has the same configuration as the front outrigger <NUM>, and includes an outer cylinder, a pair of left and right inner cylinders, an outrigger cylinder, and a pair of left and right jack cylinders.

As shown in <FIG>, the cabin <NUM> is mounted on a swing base <NUM>. The cabin <NUM> includes a driving device <NUM> (<FIG>) that drives the crane vehicle <NUM> and a steering device <NUM> (<FIG>) that steers the crane device <NUM>. That is, the crane vehicle <NUM> is a work vehicle which is a so-called rough terrain crane, in which driving of the crane vehicle <NUM> and steering of the crane device <NUM> are performed in one cabin <NUM>. However, the crane vehicle <NUM> may be an all-terrain crane including two cabins, a cabin having the driving device <NUM> and a cabin having the steering device <NUM>.

In addition, the cabin <NUM> includes a display <NUM> (<FIG>) that displays an operation state and images captured by cameras <NUM> and <NUM> to be described later. The display <NUM> is provided in the cabin <NUM> at a position where a driver seated in a driver seat can easily see the display <NUM>. The display <NUM> is connected to a controller <NUM> (<FIG>) to be described later by a cable (not shown). The display <NUM> displays image data received from the controller <NUM>.

In addition, the cabin <NUM> includes a control box (not shown). The control box houses a control substrate. The control substrate is equipped with a microcomputer, a resistor, a capacitor, a diode, and various ICs, and constitutes the controller <NUM> and a power source circuit <NUM> shown in <FIG>. In addition, a speaker <NUM> that outputs a sound is mounted on the control substrate. The speaker <NUM> outputs a sound corresponding to a sound signal received from the controller <NUM>. The speaker <NUM> and the display <NUM> are examples of a "notification device" in the present invention. The controller <NUM> and the power source circuit <NUM> will be described later.

As shown in <FIG>, the crane device <NUM> includes the swing base <NUM> rotatably supported by the vehicle body <NUM>, and a boom <NUM> supported by the swing base <NUM>. The boom <NUM> includes a base end boom <NUM>, a single or a plurality of intermediate booms <NUM>, and a tip end boom <NUM>. The base end boom <NUM>, the intermediate booms <NUM>, and the tip end boom <NUM> are arranged in a nested manner, and the boom <NUM> can be expanded and contracted. The base end boom <NUM> is supported by the swing base <NUM> so as to be raised and laid down. That is, the boom <NUM> can be raised and laid down, and can be expanded and contracted.

The boom <NUM> is reduced and laid down during traveling of the crane vehicle <NUM>. Hereafter, a posture of the boom <NUM> during the traveling will be described as a retracted posture. <FIG> shows the crane vehicle <NUM> in a state in which the boom <NUM> is in the retracted posture. A tip end portion of the boom <NUM> in the retracted posture protrudes forward from the front end of the vehicle body <NUM>.

The crane device <NUM> further includes the swing motor, a derricking cylinder by which the boom <NUM> is raised and laid down, and a telescopic cylinder that expands and contracts the boom <NUM>.

The swing motor is provided on the vehicle body <NUM>. The swing motor is rotated by being supplied with the hydraulic oil from the hydraulic device described above, and rotates the swing base <NUM> via a known gear.

The derricking cylinder is provided at the swing base <NUM>. The telescopic cylinder is provided at the boom <NUM>. The derricking cylinder and the telescopic cylinder are supplied with the hydraulic oil from the hydraulic device so as to expand and contract. The boom <NUM> is raised and laid down by the derricking cylinder that expands and contracts. The boom <NUM> is expanded and contracted by the telescopic cylinder that expands and contracts.

A jib <NUM> is attached to the boom <NUM>. The jib <NUM> is attached to a side surface (a right side surface in an example shown in <FIG>) of the boom <NUM> when the crane vehicle <NUM> travels, and is attached to the tip end portion of the boom <NUM> when the crane device <NUM> is operated. However, a presence or absence of the jib <NUM> is optional.

The crane vehicle <NUM> has a system that prevents another vehicle from coming into contact with a tip end of the boom <NUM> when entering an intersection or the like. The system includes a brake device <NUM> provided in the traveling body <NUM>, the left camera <NUM> and the right camera <NUM>, and the controller <NUM> and the power source circuit <NUM>. The details will be described below.

The brake device <NUM> includes a brake member <NUM>, and a drive device <NUM> that operates the brake member <NUM>.

The brake member <NUM> is a member that directly or indirectly applies a load (braking force) to the wheels <NUM> or the axle to prevent or stop rotation of the wheels <NUM> or the axle. The brake member <NUM> is, for example, a brake pad of a so-called disc brake or a shoe of a so-called drum brake. However, the brake member <NUM> is not limited to the brake pad or the shoe as long as the brake member <NUM> can prevent or stop the rotation of the wheels <NUM> or the axle.

The drive device <NUM> presses the brake member <NUM> against a disc or a drum to prevent the rotation of the wheels <NUM> or the axle. The drive device <NUM> is, for example, an actuator such as a hydraulic cylinder operated by a hydraulic pressure, a hydraulic motor, a pneumatic cylinder operated by a pneumatic pressure, an electric motor, or an electric cylinder. In addition, the drive device <NUM> may be an electromagnet that generates a magnetic field. The drive device <NUM> presses the brake member <NUM> having at least a part of a magnetic material against the disc or the drum by the generated magnetic field.

When the drive device <NUM> is a hydraulic cylinder or a hydraulic motor, the controller <NUM> controls driving of the drive device <NUM> by inputting a control signal to a solenoid valve provided in the hydraulic device. In addition, when the drive device <NUM> is an electric motor or an electric cylinder, the controller <NUM> controls the driving of the drive device <NUM> by inputting a control signal to a switching element provided in the drive device <NUM>. Furthermore, when the drive device <NUM> is an electromagnet, the drive device <NUM> includes an exciting coil. The exciting coil is energized by a drive circuit of the switching element. The controller <NUM> controls the driving of the drive device <NUM> by inputting a control signal to the switching element of the drive circuit. That is, the driving of the drive device <NUM> is controlled by the controller <NUM>. The controller <NUM> outputs a control signal, and thus the brake member <NUM> is pressed against the disc or the drum to stop the wheels <NUM>.

The brake member <NUM> may be pressed against the disc or the drum in conjunction with a brake pedal (not shown) provided in the cabin <NUM> in addition to the drive device <NUM>. That is, the brake member <NUM> is automatically pressed against the disc or the drum by the controller <NUM>, and is manually pressed against the disc or the drum by the driver.

The left camera <NUM> and the right camera <NUM> (hereinafter also referred to as the cameras <NUM> and <NUM>) shown in <FIG> each include an imaging element, and generate and output image data by performing imaging (image capturing). The cameras <NUM> and <NUM> are connected to the power source circuit <NUM> and the controller <NUM> (<FIG>) by cables (not shown). The cameras <NUM> and <NUM> are driven by being supplied with power from the power source circuit <NUM>, and receive a control signal from the controller <NUM> to perform imaging. The image data output by the cameras <NUM> and <NUM> is input to the controller <NUM> through the cables. The image data is an example of "detection data" in the present invention.

As shown in <FIG>, the cameras <NUM> and <NUM> are provided at the tip end portion of the boom <NUM>. Specifically, the left camera <NUM> is fixed to a left side surface of a tip end portion of the tip end boom <NUM>. A lens of the left camera <NUM> faces a left side of the vehicle body <NUM>. That is, the left camera <NUM> images the left side of the tip end portion of the boom <NUM>. The right camera <NUM> is fixed to a right side surface of the tip end portion of the tip end boom <NUM>. A lens of the right camera <NUM> faces a right side of the vehicle body <NUM>. That is, the right camera <NUM> images the right side of the tip end portion of the boom <NUM>.

The cameras <NUM> and <NUM> each include a distance measuring sensor and a motor that realize an automatic focusing function. The distance measuring sensor is an ultrasonic sensor, a laser sensor, or the like, detects a distance to an obstacle (subject), and outputs distance data indicating a detected distance. The motor moves the lens or the like to adjust a focal length. Each of the cameras <NUM> and <NUM> drives the motor such that a distance indicated by the distance data output by the distance measuring sensor and the focal length are the same distance. In addition, the cameras <NUM> and <NUM> output the distance data together with the image data generated by imaging. The output distance data is input to the controller <NUM> through the cables. The cameras <NUM> and <NUM> correspond to a "sensor" in the present invention. The distance data is an example of the "detection data" in the present invention.

The power source circuit <NUM> shown in <FIG> is a circuit that generates power to be supplied to the display <NUM>, the cameras <NUM> and <NUM>, and the drive device <NUM>. The power source circuit <NUM> is, for example, a DC-DC converter. The power source circuit <NUM> converts a DC voltage supplied from the battery <NUM> into a stable DC voltage having a predetermined voltage value and outputs the stable DC voltage. For example, the power source circuit <NUM> converts a DC voltage of such as <NUM> V or <NUM> V supplied from the battery <NUM> into a stable DC voltage of such as <NUM> V, <NUM> V, or <NUM> V and outputs the stable DC voltage. The power source circuit <NUM> is, for example, a switching regulator including a switching element. The controller <NUM> controls driving of the display <NUM> and the cameras <NUM> and <NUM> by inputting a control signal to the switching element of the power source circuit <NUM> or outputting a signal for turning on and off a switch provided between an output terminal of the power source circuit <NUM> and the display <NUM> or the cameras <NUM> and <NUM>.

The controller <NUM> includes a CPU <NUM>, which is a central processing unit, a ROM <NUM>, a RAM <NUM>, and a memory <NUM>.

The ROM <NUM> stores an OS <NUM>, which is an operation system, and a control program <NUM>. The control program <NUM> is executed by the CPU <NUM> executing an instruction described in an address. The control program <NUM> executes brake control processing which will be described later.

The RAM <NUM> is used to execute the control program <NUM>. The memory <NUM> stores data necessary for executing the control program <NUM>. Specifically, the memory <NUM> stores a threshold distance and a first threshold.

The control program <NUM> executes, based on the image data received from the cameras <NUM> and <NUM>, the brake control processing for controlling the driving of the drive device <NUM>. Hereafter, the processing executed by the control program <NUM> is described as processing executed by the controller <NUM>.

As shown in <FIG>, the controller <NUM> determines whether or not the crane vehicle <NUM> is traveling (S11), and executes processing of step S12 and subsequent steps when it is determined that the crane vehicle <NUM> is traveling (S11: Yes). That is, the brake control processing is executed when the crane vehicle <NUM> is traveling. For example, the controller <NUM> determines that the crane vehicle <NUM> is not traveling according to a fact that the engine is not driven or the crane device <NUM> is being operated (S11: No). In addition, the controller <NUM> determines that the crane vehicle <NUM> is traveling according to facts that the engine is being driven and the crane device <NUM> is not being operated (S11: Yes).

When it is determined that the crane vehicle <NUM> is traveling (S11: Yes), the controller <NUM> executes camera drive processing (S12). Specifically, the controller <NUM> supplies power to the cameras <NUM> and <NUM> by controlling driving of the power source circuit <NUM>, and inputs a control signal to the cameras <NUM> and <NUM> to cause the cameras <NUM> and <NUM> to perform imaging.

When the control signal is input, each of the cameras <NUM> and <NUM> causes the distance measuring sensor to detect a distance to an obstacle (subject), adjusts a focal length according to the distance detected by the distance measuring sensor, and performs imaging. The cameras <NUM> and <NUM> each output image data generated by the imaging and the distance (hereinafter referred to as an obstacle distance) detected by the distance measuring sensor. The image data and the obstacle distances output by the cameras <NUM> and <NUM> are input to the controller <NUM>. The controller <NUM> executes obstacle detection processing for detecting an obstacle by analyzing the received image data (S13).

For example, the controller <NUM> calculates a displacement point at which a color, luminance, or lightness changes by a threshold or more in the received image data. The controller <NUM> detects a region surrounded by the displacement points as an obstacle. The number of obstacles detected by the controller <NUM> is one or more. Other existing methods may be used to detect the obstacles. In addition, the controller <NUM> may determine a subject determined by the cameras <NUM> and <NUM> as an obstacle. Furthermore, in order to reduce the number of operations of the CPU <NUM>, binarization processing or the like may be used for the obstacle detection processing.

Next, the controller <NUM> determines, based on the received obstacle distance, whether or not the detected obstacle is approaching the tip end portion of the boom <NUM> (S14). Specifically, the controller <NUM> executes the camera drive processing at the step S12 periodically (for example, at intervals of <NUM> seconds). Then, the controller <NUM> periodically receives input of the obstacle distance. The controller <NUM> determines that the obstacle is approaching according to the fact that the obstacle distance decreases over time (S14: Yes). The controller <NUM> determines that the obstacle is not approaching according to the fact that the obstacle distance increases over time or the obstacle distance does not change over time (S14: No).

When it is determined that the obstacle is not approaching (S14: No), the controller <NUM> determines whether or not traveling of the crane vehicle <NUM> is ended (S21). For example, the controller <NUM> determines that the traveling of the crane vehicle <NUM> is ended according to a fact that the engine is stopped (S21: Yes), and determines that the traveling of the crane vehicle <NUM> is not ended according to a fact that the engine is not stopped (S21: No). The controller <NUM> ends the brake control processing according to a determination that the traveling of the crane vehicle <NUM> is ended (S21: Yes). Meanwhile, the controller <NUM> continues to execute processing of step S14 and subsequent steps according to a determination that the traveling of the crane vehicle <NUM> is not ended (S21: No).

When it is determined in step S14 that the obstacle is approaching (S14: Yes), the controller <NUM> determines whether or not an obstacle distance of the approaching obstacle is less than the threshold distance stored in the memory <NUM>. The threshold distance is, for example, <NUM> to <NUM>. That is, the controller <NUM> determines whether or not a distance to the approaching obstacle is a distance that may cause contact between the boom <NUM> and the obstacle.

When it is determined that the obstacle distance to the approaching obstacle is not less than the threshold distance (S15: No), the controller <NUM> skips processing of steps S15 to S20, and executes processing of step S21.

Meanwhile, when it is determined that the obstacle distance to the approaching obstacle is less than the threshold distance (S15: Yes), the controller <NUM> determines whether or not an obstacle height, which is a height of an obstacle from ground, is equal to or greater than the first threshold stored in the memory <NUM>. Specifically, the controller <NUM> calculates the obstacle height based on the received image data and obstacle distance, and determines whether or not the calculated obstacle height is equal to or greater than the first threshold. The obstacle height corresponds to a vehicle height when the obstacle is a vehicle. The first threshold is a value corresponding to a height of the tip end portion of the boom <NUM> in a retracted posture from ground, and is, for example, <NUM> to <NUM>. That is, the controller <NUM> determines whether or not an obstacle, such as an approaching vehicle, may come into contact with the boom <NUM>.

When it is determined that the obstacle height is not equal to or greater than the first threshold (S16: No), that is, when it is determined that there is no risk that the approaching obstacle comes into contact with the boom <NUM>, the controller <NUM> skips processing of steps S17 to S20, and executes processing of step S21.

Meanwhile, when it is determined that the obstacle height is equal to or greater than the first threshold (S16: Yes), that is, when it is determined that the approaching obstacle may come into contact with the boom <NUM>, the controller <NUM> executes the brake drive processing (S17). Specifically, the controller <NUM> inputs a control signal to the drive device <NUM> of the brake device <NUM> to press the brake member <NUM> against the disc or the drum, so as to stop the wheels <NUM>.

Then, the controller <NUM> executes notification processing (S18). Specifically, the controller <NUM> inputs a sound signal to the speaker <NUM> to cause the speaker <NUM> to output a warning sound, or inputs image data to the display <NUM> to cause the display <NUM> to display a warning screen. The sound signal and the image data output from the controller <NUM> in the notification processing are stored in the memory <NUM> in advance.

After executing the processing of step S18, the controller <NUM> determines whether or not the detected obstacle continues approaching (S19). The determination processing of step S19 is executed in the same manner as the determination processing of step S14.

When it is determined that the obstacle continues approaching (S19: Yes), the controller <NUM> continues to execute the driving of the drive device <NUM> of the brake device <NUM> and the notification processing (S18).

The brake drive processing of step S17 may be executed in a plurality of stages. Specifically, the controller <NUM> first drives the brake device <NUM> as a preliminary brake, and then drives the brake device <NUM> as a main brake when it is determined that the obstacle continues approaching. In the preliminary brake and the main brake, a pressing force for pressing the brake member <NUM> against the disc or the drum may be changed. For example, in the preliminary brake, the brake member <NUM> is pressed against the disc or the drum with a pressing force lower than that in the main brake.

When it is determined that the obstacle is not approaching as the obstacle such as a vehicle makes a right or left turn, the obstacle passes an intersection, or the obstacle stops (S19: No), the controller <NUM> executes brake release processing (S20). Specifically, the controller <NUM> stops input of the control signal to the drive device <NUM> of the brake device <NUM>. Then, the controller <NUM> determines whether or not the traveling of the crane vehicle <NUM> is stopped (S21), and continues to execute the processing of step S14 and subsequent steps when it is determined that the traveling of the crane vehicle <NUM> is not stopped (S21: No). When it is determined that the traveling of the crane vehicle <NUM> is stopped (S21: Yes), the controller <NUM> ends the brake control processing.

The controller <NUM> drives the brake device <NUM> based on the image data and the obstacle distance received from the cameras <NUM> and <NUM> that are provided at the tip end portion of the boom <NUM> and detect an obstacle on a lateral side of the vehicle body <NUM>. Therefore, the crane vehicle <NUM> can prevent another vehicle or the like (obstacle) from coming into contact with the tip end portion of the boom <NUM> when entering an intersection or the like.

In addition, the controller <NUM> does not drive the brake device <NUM> when the detected obstacle is stopped or moves away (S14: No), and drives the brake device <NUM> when the detected obstacle is approaching (S14: Yes). Therefore, the crane vehicle <NUM> can drive the brake device <NUM> to stop the vehicle body <NUM> when another vehicle or the like (obstacle) may come into contact with the tip end portion of the boom <NUM>. That is, the crane vehicle <NUM> can appropriately stop the vehicle body <NUM>.

Further, the controller <NUM> does not drive the brake device <NUM> when the detected obstacle is a motorcycle, a person, or an automobile at a height where the obstacle does not come into contact with the boom <NUM> (S16: No), and drives the brake device <NUM> when the detected obstacle is an automobile or the like at a height where the obstacle comes into contact with the boom <NUM> (S16: Yes). Therefore, the crane vehicle <NUM> can stop the vehicle body <NUM> more appropriately.

Furthermore, when the obstacle is no longer detected, or the obstacle moves away from the boom <NUM> (S19: No), the controller <NUM> stops the driving of the brake device <NUM> (S20) to enable travelling of the crane vehicle <NUM>. Therefore, the brake device <NUM> is prevented from being driven unnecessarily. As a result, usability of the crane vehicle <NUM> is improved.

Moreover, the controller <NUM> executes the notification processing (S18) according to the driving of the brake device <NUM> (S17). Therefore, the driver can easily recognize that the vehicle body <NUM> is stopped according to a fact that an obstacle may come into contact with the boom <NUM>.

In the first embodiment, an example is described in which the brake device <NUM> is driven to stop the crane vehicle <NUM> when an obstacle detected by the cameras <NUM> and <NUM> may come into contact with the boom <NUM>. In the present embodiment, an example will be described in which a lighting device <NUM> and a horn <NUM> shown in <FIG> are driven and displayed on the display <NUM> when an obstacle detected by the cameras <NUM> and <NUM> may come into contact with the boom <NUM>. A configuration of the crane vehicle <NUM> other than the lighting device <NUM> and the horn <NUM> in the present embodiment is the same as a configuration of the crane vehicle <NUM> described in the first embodiment.

The lighting device <NUM> is, for example, a rotary lamp in which a direction of light to be emitted rotates. The lighting device <NUM> is provided, for example, at the tip end portion of the boom <NUM>, a tip end portion of a support member (not shown) extending from the traveling body <NUM> to a position corresponding to the tip end portion of the boom <NUM>, or a front end portion of the traveling body <NUM>. That is, the lighting device <NUM> is installed at a position that can be visually recognized by a driver of a vehicle approaching the boom <NUM>. The lighting device <NUM> is turned on by power supplied from the power source circuit <NUM>. For example, the controller <NUM> turns on and off the lighting device <NUM> by outputting a control signal for turning on and off a switch provided between the power source circuit <NUM> and the lighting device <NUM>.

The horn <NUM> is a device, a speaker, or the like that outputs a horn sound when a pressure is applied. The controller <NUM> causes the horn <NUM> to issue a notification of a sound such as a horn sound, for example, by inputting a control signal to a pressing device that applies a pressure to the horn <NUM> or by inputting a sound signal to the horn <NUM>. The lighting device <NUM> and the horn <NUM> are examples of the "notification device" according to the present invention. Only one of the lighting device <NUM> and the horn <NUM> may be provided on the crane vehicle <NUM>.

The controller <NUM> executes notification processing shown in <FIG> instead of the brake control processing (<FIG>) described in the first embodiment. Hereinafter, the notification processing will be described with reference to <FIG>. The same processing as that of the first embodiment is donated by the same reference numeral (step number) as that of the first embodiment and a description thereof is omitted.

As in the first embodiment, the controller <NUM> executes the processing from step S11 to step S16. Then, in step S16, the controller <NUM> determines whether or not the obstacle approaching the threshold distance is an obstacle at a height where the obstacle comes into contact with the boom <NUM>.

When it is determined that the obstacle approaching the threshold distance is an obstacle at a height where the obstacle comes into contact with the boom <NUM> (S16: Yes), the controller <NUM> executes notification device drive processing (S41). Specifically, the controller <NUM> turns on the lighting device <NUM>, causes the horn <NUM> to output the horn sound, and further causes the display <NUM> to display that an obstacle is approaching.

Next, the controller <NUM> determines whether or not the obstacle continues approaching (S19), as in the first embodiment. That is, the controller <NUM> determines whether or not a driver of an obstacle (vehicle) who detects a danger from lighting of the lighting device <NUM> or the horn sound stops the vehicle. When it is determined that the obstacle continues approaching (S19: Yes), the controller <NUM> continues to execute the notification device drive processing. When it is determined that the obstacle is no longer approaching as the obstacle is stopped, turned left or right, retreated, or the like (S19: No), the controller <NUM> executes notification stop processing (S42). Specifically, the controller <NUM> turns off the lighting device <NUM>, stops output of the control signal and the sound signal to the horn <NUM>, and further stops displaying of the display <NUM> that an obstacle is approaching. Thereafter, the controller <NUM> executes the processing of step S21 as in the first embodiment.

By executing the notification processing, the crane vehicle <NUM> can make a driver of a vehicle, which may approach the tip end portion of the boom <NUM> and come into contact with the tip end portion of the boom <NUM>, recognize that there is a risk of coming into contact with the tip end portion of the boom <NUM>. As a result, safety of the crane vehicle <NUM> is improved.

As shown in <FIG> and <FIG>, the crane vehicle <NUM> according to the present modification further includes a front camera <NUM> in addition to the left and right cameras <NUM> and <NUM>. The front camera <NUM> is fixed to a front surface of the tip end portion of the boom <NUM>. A lens of the front camera <NUM> faces a front side of the crane vehicle <NUM>. That is, the front camera <NUM> images the front side of the crane vehicle <NUM>. A configuration of the front camera <NUM> is the same as a configuration of each of the left and right cameras <NUM> and <NUM>. The front camera <NUM> is connected to the controller <NUM> using a cable. The front camera <NUM> may be provided at a lower surface, an upper surface, the left side surface, or the right side surface of the tip end portion of the boom <NUM> as long as the front camera <NUM> can image the front side with the lens facing forward.

In addition, the crane vehicle <NUM> includes a speed sensor <NUM>. The speed sensor <NUM> periodically or constantly outputs a signal corresponding to a vehicle speed of the crane vehicle <NUM>, for example, according to the driving of the engine. The speed sensor <NUM> is connected to the controller <NUM> using a cable (not shown). The signal output from the speed sensor <NUM> is input to the controller <NUM> via an interface. A configuration of the speed sensor <NUM> is already known, and thus a detailed description thereof is omitted.

Furthermore, the memory <NUM> of the controller <NUM> further stores a second threshold in addition to the first threshold and the threshold distance. The second threshold is a value corresponding to an uppermost position of the boom <NUM> or the jib <NUM> (<FIG>) attached to the boom <NUM>. The second threshold may be set to different values depending on a case where the jib <NUM> is not attached to the boom <NUM> and a case where the jib <NUM> is attached to the boom <NUM>, or may be set assuming that the jib <NUM> is mounted on the boom <NUM>.

Further, the crane vehicle <NUM> includes a release button <NUM> (<FIG>). The release button <NUM> is provided in the cabin <NUM>. The release button <NUM> outputs a release signal according to an operation performed by a driver. The release button <NUM> is connected to the controller <NUM> by a cable (not shown). As will be described later, the controller <NUM> stops the driving of the brake device <NUM> according to input of the release signal. That is, when the release button <NUM> is operated, the wheels <NUM> are released from the brake member <NUM>, and the crane vehicle <NUM> can travel.

A configuration other than the front camera <NUM>, the speed sensor <NUM>, and the second threshold is the same as the configuration of the crane vehicle <NUM> described in the embodiment.

The controller <NUM> executes brake control processing shown in <FIG> in addition to the brake control processing (<FIG>) described in the embodiment. The same processing as that of the embodiment is donated by the same reference numeral as that of the embodiment, and a description thereof is omitted.

As in the embodiment, the controller <NUM> determines whether or not the crane vehicle <NUM> is traveling (S11). When it is determined that the crane vehicle <NUM> is traveling (S11: Yes), the controller <NUM> executes front camera drive processing (S31). Specifically, the controller <NUM> supplies power to the front camera <NUM> and inputs a control signal to the front camera <NUM> to cause the front camera <NUM> to perform imaging. The front camera <NUM> which receives the control signal adjusts a focal length to perform imaging in the same manner as the left and right cameras <NUM> and <NUM>, and outputs an obstacle distance and image data. The image data and the obstacle distance output from the front camera <NUM> are input to the controller <NUM>. The controller <NUM> executes obstacle detection processing for detecting an obstacle by analyzing the received image data (S32). A method for detecting an obstacle on the front side is the same as a method for detecting obstacles on the left side and the right side.

The controller <NUM> determines whether or not a detected obstacle is a static obstacle. For example, when a change amount per unit time of the obstacle distance (that is, an obstacle approaching speed) received from the front camera <NUM> is substantially equal to a speed of the crane vehicle <NUM> (hereinafter, also referred to as a vehicle speed) indicated by the signal received from the speed sensor <NUM>, the controller <NUM> determines that the detected obstacle is a static obstacle (S33: Yes). For example, when the obstacle approaching speed is within a range of the vehicle speed ± a threshold speed, the controller <NUM> determines that the obstacle approaching speed is substantially equal to the vehicle speed. The threshold speed is stored in the memory <NUM> in advance.

When it is determined that the detected obstacle is not a static obstacle (S33: No), the controller <NUM> skips processing of step S34, etc., and executes processing of step S21 as in the embodiment.

When it is determined that the detected obstacle is a static obstacle (S33: Yes), the controller <NUM> determines whether or not a height of a lowest point of the static obstacle from ground is less than the second threshold stored in the memory <NUM> (S34). That is, the controller <NUM> determines whether or not the crane vehicle <NUM> can pass below the static obstacle without contact between the static obstacle and the boom <NUM>. Such determination processing is not necessary for a vehicle such as a normal vehicle whose vehicle height is overwhelmingly lower than that of the crane vehicle <NUM>.

When it is determined that the height of the lowest point of the static obstacle from the ground is not less than the second threshold stored in the memory <NUM> (S34: No), that is, when it is determined that the boom <NUM> is not coming into contact with the static obstacle, the controller <NUM> skips processing of steps S17 to S20, and executes processing of step S21.

When it is determined that the height of the lowest point of the static obstacle from the ground is less than the second threshold (S34: Yes), that is, when it is determined that the boom <NUM> is coming into contact with the static obstacle, the controller <NUM> executes the brake drive processing of driving the brake device <NUM> (S17). Thereafter, the controller <NUM> executes the processing of step S18 as in the embodiment.

After executing the notification processing of step S18, the controller <NUM> determines whether or not a release signal is received from the release button <NUM> (S35). That is, the controller <NUM> determines whether or not the driver operates the release button <NUM>. The controller <NUM> continuously executes the notification processing until the release signal is input (S35: No).

When it is determined that the release signal is input (S35: Yes), the controller <NUM> executes the brake release processing (S20) in the same manner as in the embodiment. After executing the brake release processing, the controller <NUM> executes the processing of step S21 in the same manner as in the embodiment, and ends the brake control processing.

When it is determined that a static obstacle in front of the vehicle body <NUM> such as an elevated structure is coming into contact with the boom <NUM>, the controller <NUM> drives the brake device <NUM> to stop the vehicle body <NUM>. Therefore, the crane vehicle <NUM> can travel safely by preventing contact between the static obstacle such as the elevated structure and the boom <NUM>.

The controller <NUM> may determine whether or not an obstacle in front of the vehicle body <NUM> is a moving obstacle such as another vehicle. In this case, the controller <NUM> may drive the brake device <NUM> according to the moving obstacle approaching within a threshold safety distance. The threshold safety distance is, for example, <NUM> to <NUM>, and is stored in the memory <NUM> in advance.

In addition, as shown in <FIG>, instead of the cameras <NUM>, <NUM>, and <NUM> (<FIG>), a camera <NUM> having a wide-angle lens capable of imaging the left side, the right side, and the front side may be provided at the tip end portion of the boom <NUM>. Further, instead of providing the front camera <NUM>, each of the left and right cameras <NUM> and <NUM> may have a wide-angle lens capable of imaging up to the front side of the vehicle body <NUM>.

In the embodiments described above, the cameras <NUM> and <NUM> that output the image data and the distance data are described as an example of the sensor. However, the sensor may be an ultrasonic sensor, a radar, or the like. When a two-dimensional sensor such as an ultrasonic sensor that can measure a distance to an obstacle but cannot measure a height or a size of the obstacle is used, a plurality of two-dimensional sensors may be used. For example, a first two-dimensional sensor (such as an ultrasonic sensor) is provided such that a direction along a horizontal direction is a detection direction, and the other one or a plurality of two-dimensional sensors are provided such that detection directions are shifted in vertical and horizontal directions with respect to the first two-dimensional sensor. By using the plurality of two-dimensional sensors, the height, the size, and the like of the obstacle can be detected in addition to the distance to the obstacle. When the brake device <NUM> is driven according to the distance to the obstacle being less than the threshold distance, only the distance to the obstacle may be measured by one two-dimensional sensor (such as an ultrasonic sensor).

In the embodiments and the modifications described above, an example is described in which the controller <NUM> executes the brake control processing shown in <FIG> according to the traveling of the crane vehicle <NUM>. However, the controller <NUM> may execute the brake control processing shown in <FIG> according to the crane vehicle <NUM> entering an intersection. For example, the controller <NUM> analyzes image data received from the front camera <NUM>, and determines whether or not the crane vehicle <NUM> enters an intersection.

In the embodiments and the modifications described above, an example is described in which the obstacle distance is detected using the distance measuring sensors provided in the cameras <NUM>, <NUM>, and <NUM>. However, in addition to the cameras <NUM>, <NUM>, and <NUM>, a distance measuring sensor may be provided at the tip end portion of the boom <NUM>.

In the first embodiment described above, an example is described in which the notification processing is executed in step S18 after the brake device <NUM> is driven in step S17. However, the brake device <NUM> may be driven after the notification processing is executed. That is, the driver may be notified that the brake device <NUM> is to be driven, before the brake device <NUM> is driven.

In the first embodiment described above, an example is described in which both the brake drive processing (S17) and the notification processing (S18) are executed. However, only one of the brake drive processing and the notification processing may be executed.

In the second embodiment described above, an example is described in which the notification device drive processing (step <NUM> in <FIG>) in which the lighting device <NUM> or the horn <NUM> is driven is executed instead of the brake drive processing (step S17 in <FIG>) in the first embodiment. However, the notification device drive processing may be executed together with the brake drive processing. In this case, driving of the lighting device <NUM> or the horn <NUM> may be executed before the driving of the brake device <NUM> or after the driving of the brake device <NUM>.

In the second embodiment described above, an example is described in which the notification device drive processing (step <NUM> in <FIG>) in which the lighting device <NUM> or the horn <NUM> is driven is executed instead of the notification processing (S18 in <FIG>) in the first embodiment. However, the notification device drive processing may be executed together with the notification processing (S18 in <FIG>).

Claim 1:
A work vehicle comprising:
a vehicle body (<NUM>) including a wheel (<NUM>);
a boom (<NUM>) protruding forward from a front end of the vehicle body (<NUM>);
a brake device (<NUM>) configured to apply a braking force to the wheel (<NUM>); and
a controller (<NUM>) configured to drive the brake device (<NUM>) based on detection data received from a sensor
characterized in that
the sensor is provided at a position corresponding to a tip end portion of the boom (<NUM>), and configured to detect an obstacle on a lateral side of the tip end portion;
the sensor recovering at least on the left side and on the right side of the tip end portion of the boom (<NUM>) is configured to detect an obstacle when the work vehicle enters an intersection, and
the controller (<NUM>) is configured to determine whether or not a detected obstacle is approaching the tip end portion of the boom (<NUM>) based on the detection data, and drive the brake device (<NUM>) according to a determination that the detected obstacle is approaching the tip end portion.