Crawler vehicle with rotatable superstructure and method thereof

Abstract

A tracked vehicle, comprising: a vehicle body including a lower structure and an upper structure, the upper structure being rotatable relative to the lower structure about an axis; an angle sensor for detecting rotation of the upper structure relative to the lower structure; a first track assembly and a second track assembly respectively mounted on opposite sides of the vehicle body; a prime mover; an electronic control unit (ECU); and a transmission for controllably transferring power from the prime mover to the track assemblies based on the output of the ECU. The ECU is configured to, in response to the angle sensor having detected a relative angular displacement exceeding a threshold angular displacement, perform the following operations: issue a signal via an output interface to indicate that a directional switch may be requested; and the transmission responds to the detected directional switch request to perform a directional switch on the tracked vehicle.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 201780003402.9, with International Application No. PCT / CA2017 / 050876, filing date of July 20, 2017, and title "Crawler Vehicle with Rotatable Superstructure and Method Thereof".

[0002] Cross - reference to related applications

[0003] This application claims priority under 35 U.S.C. 119 to U.S. Provisional Patent Application 62 / 364,588, filed on July 20, 2016, the content of which is incorporated herein by reference. Technical field

[0004] This application generally relates to crawler vehicles, and more particularly to crawler vehicles having a rotatable superstructure and methods for controlling the operation of such crawler vehicles. Background art

[0005] Crawler vehicles having a rotatable superstructure can be used in various applications (such as construction, excavation, or vegetation management), where rotation of the superstructure is used to transfer materials from a source to a destination while minimizing the movement of the vehicle on the ground. Nevertheless, the vehicle must also be able to travel relative to the ground, and thus the cab has acceleration, braking, and steering functions.

[0006] Problems can arise because the cab is located on the superstructure of the crawler vehicle that rotates relative to the lower structure. Specifically, although the operator can put the engine in "drive" and can enable the accelerator, the actual movement of the vehicle as perceived by the operator will still further depend on the relative rotation angle of the superstructure relative to the lower structure. In other words, the operator's request for "forward" movement may result in the vehicle perceiving forward or backward movement, depending on the relative rotation angle, and the operator may not remember this relative rotation angle because his or her attention is focused on operating the work implement, etc. Thus, this uncertainty in the direction of movement on which the crawler vehicle will move when the accelerator is enabled may lead to hesitation in operation, may require additional operator training, and may result in accidents. Summary of the invention

[0007] According to a first aspect, there is provided a method, comprising:

[0008] detecting a rotation of a superstructure of a crawler vehicle relative to a lower structure of the crawler vehicle about an axis;

[0009] signaling that a directional switch can be requested in response to a rotation resulting in a relative angular displacement that exceeds a threshold angular displacement;

[0010] In response to a directional switching request after a signaling, perform a directional switch on the tracked vehicle.

[0011] According to a clause of the first aspect, the method further includes generating a directional switching request.

[0012] According to a clause of the first aspect, the method is executed by a processor of an electronic control unit, wherein generating the directional switching request is executed by the processor without input from an operator of the tracked vehicle.

[0013] According to a clause of the first aspect, the method is executed by a processor of an electronic control unit, wherein generating the directional switching request is executed by the processor in response to input from an operator of the tracked vehicle.

[0014] According to a clause of the first aspect, the method further includes controlling track assemblies on opposite lateral sides of the tracked vehicle to cause movement of the tracked vehicle in response to a requirement by the operator for the tracked vehicle to move forward or backward;

[0015] wherein before performing the directional switch, controlling the track assemblies to effect movement of the tracked vehicle (i) in a first direction in response to a requirement by the operator for the tracked vehicle to move forward; and (ii) in a second direction opposite to the first direction in response to a requirement by the operator for the tracked vehicle to move backward;

[0016] wherein to perform the directional switch, the method includes controlling the track assemblies to effect movement of the tracked vehicle (i) in the second direction in response to a requirement by the operator for the tracked vehicle to move forward, and (ii) in the first direction in response to a requirement by the operator for the tracked vehicle to move backward.

[0017] According to a clause of the first aspect, the method further includes detecting the directional switching request, and wherein detecting the directional switching request includes detecting that a specific control input device has been activated by an operator of the tracked vehicle.

[0018] According to a clause of the first aspect, wherein signaling the availability of the directional switch request includes emitting at least one of an audible alarm and an optical alarm through an output interface of the tracked vehicle.

[0019] According to a clause of the first aspect, signal the availability of the directional switch request only if at least a vehicle stability condition is also met.

[0020] According to a clause of the first aspect, the vehicle stability condition includes the tracked vehicle having zero speed in the travel plane of the tracked vehicle.

[0021] According to a clause of the first aspect, the vehicle stability condition includes that the tracked vehicle has a speed less than a predetermined maximum speed.

[0022] According to a clause of the first aspect, the vehicle stability condition includes that the tracked vehicle is in neutral or park.

[0023] According to a clause of the first aspect, the vehicle stability condition includes that the accelerator of the tracked vehicle has been released and / or the brake of the tracked vehicle has been applied by the operator of the tracked vehicle.

[0024] According to a clause of the first aspect, the vehicle stability condition includes that the tracked vehicle is tilted less than a predetermined maximum tilt angle.

[0025] According to a clause of the first aspect, the axis is perpendicular to the travel plane of the tracked vehicle.

[0026] According to a clause of the first aspect, the directional switching of the tracked vehicle is performed in response to a directional switching request only after signaling that at least the vehicle stability condition is also satisfied.

[0027] According to a clause of the first aspect, if a directional switching request occurs after signaling without the vehicle stability condition being satisfied, the method further includes signaling that the directional switching is not performed.

[0028] According to a clause of the first aspect, signaling that the directional switching is not performed includes emitting at least one of an audible alarm and an optical alarm to the operator of the tracked vehicle through an output interface of the tracked vehicle.

[0029] According to a clause of the first aspect, the method further includes emitting at least one of an audible alarm and an optical alarm through an output interface of the tracked vehicle when the vehicle stability condition has been satisfied.

[0030] According to a clause of the first aspect, signaling that a directional switching request is available to the operator of the tracked vehicle includes emitting at least one of an additional audible alarm and an additional optical alarm through an output interface of the tracked vehicle.

[0031] According to a clause of the first aspect, the directional switching of the tracked vehicle is performed in response to a directional switching request only after signaling that at least the vehicle operation condition is also satisfied.

[0032] According to a clause of the first aspect, the vehicle operation condition includes that the work implement activation lever is unlocked.

[0033] According to a clause of the first aspect, the threshold angular displacement is approximately 90 degrees.

[0034] According to a clause of the first aspect, the method further comprises:

[0035] In response to a relative angular displacement caused by rotation that exceeds a second threshold angular displacement and no directional switching request occurs after signaling, stop signaling that a directional switching can be requested.

[0036] According to a clause of the first aspect, the method further comprises not performing a directional switch on the tracked vehicle in response to detecting a directional switching request after the stop of signaling.

[0037] According to a clause of the first aspect, the difference between the second threshold angular displacement and the first threshold angular displacement is about 180 degrees.

[0038] According to an aspect of the first aspect, the directional switch is a first directional switch, and after performing the first directional switch, the method further comprises:

[0039] In response to a relative angular displacement caused by rotation that exceeds a second threshold angular displacement, signal a second time that a directional switching can be requested; and

[0040] In response to detecting a directional switching request after the second signaling, perform a second directional switch on the tracked vehicle.

[0041] According to a clause of the first aspect, the method further comprises: after performing the first directional switch, setting the second threshold angular displacement to be 180 degrees offset from the first threshold angular displacement.

[0042] According to a clause of the first aspect, the method further comprises:

[0043] Controlling track assemblies on opposite lateral sides of the tracked vehicle to cause the tracked vehicle to move in response to a forward or backward movement requirement of an operator for the tracked vehicle,

[0044] wherein the track assemblies are controlled to cause the tracked vehicle to (i) move in a first direction in response to a forward movement requirement of an operator for the tracked vehicle and (ii) move in a second direction opposite to the first direction in response to a backward movement requirement of an operator for the tracked vehicle before performing the first directional switch;

[0045] wherein to perform the second directional switch, the method comprises controlling the track assemblies to cause the tracked vehicle to (i) move in a first direction in response to a forward movement requirement of an operator for the tracked vehicle and (ii) move in a second direction in response to a backward movement requirement of an operator for the tracked vehicle.

[0046] According to a clause of the first aspect, the method further includes: recording the number of directional switches performed since the tracked vehicle was manufactured.

[0047] According to a clause of the first aspect, the method further includes: performing a plurality of sequential directional switches, wherein every second directional switch represents a factory reset, wherein each intermediate directional switch represents a directional setting opposite to the factory setting, and wherein the method further includes keeping track of whether the current directional setting of the tracked vehicle is the factory setting.

[0048] According to a clause of the first aspect, the method further includes emitting a signal to indicate whether the current directional setting of the tracked vehicle is the factory setting.

[0049] According to a clause of the first aspect, the method further includes: detecting a fault regarding detecting rotation of the superstructure of the tracked vehicle relative to the substructure of the tracked vehicle about the axis and emitting a signal to indicate that the detection fault has occurred.

[0050] According to a clause of the first aspect, the method further includes: in response to detecting the detection fault, emitting a signal to alert the operator of the tracked vehicle that a directional switch is not requestable.

[0051] According to a second aspect, there is provided a tracked vehicle, comprising:

[0052] A vehicle body, the vehicle body including a substructure and a superstructure, the superstructure being rotatable relative to the substructure about an axis;

[0053] An angle sensor for detecting rotation of the superstructure about the axis relative to the substructure;

[0054] A first track assembly and a second track assembly, respectively mounted on opposite lateral sides of the vehicle body;

[0055] A prime mover;

[0056] An electronic control unit; and

[0057] A transmission for controllably transmitting power from the prime mover to the track assemblies based on the output of the electronic control unit;

[0058] The electronic control unit is configured to respond to the angle sensor having detected a relative angular displacement exceeding a threshold angular displacement by:

[0059] Emitting a signal via an output interface to indicate that a directional switch is requestable; and

[0060] In response to detecting a directional switch request after the signal is emitted, the transmission performs a directional switch on the tracked vehicle.

[0061] According to a clause of the second aspect, the transmission is configured to control the track assembly to effect movement of the tracked vehicle (i) in a first direction in response to an operator's request for forward movement of the tracked vehicle; and (ii) in a second direction opposite the first direction in response to an operator's request for backward movement of the tracked vehicle, and wherein, to effect a directional switch, the transmission is configured to control the track assembly to effect movement of the tracked vehicle (i) in the second direction in response to an operator's request for forward movement of the tracked vehicle, and (ii) in the first direction in response to an operator's request for backward movement of the tracked vehicle.

[0062] According to a clause of the second aspect, the sensor is a first sensor, and the tracked vehicle further includes a second sensor for detecting rotation of the superstructure relative to the substructure about an axis, wherein the electronic control unit configured to respond to a relative angular displacement in which the sensor has detected a relative angular displacement exceeding a threshold angular displacement includes an electronic control unit configured to respond to a combined value of relative angular displacements in which both the first sensor and the second sensor have detected a relative angular displacement exceeding the threshold angular displacement.

[0063] According to a clause of the second aspect, the combined value is an average value.

[0064] According to a clause of the second aspect, the sensor is a first sensor, and the tracked vehicle further includes a second sensor for detecting rotation of the superstructure relative to the substructure about an axis, wherein the electronic control unit configured to respond to a relative angular displacement in which the sensor has detected a relative angular displacement exceeding a threshold angular displacement includes an electronic control unit configured to respond to the first sensor if the second sensor fails and to respond to the second sensor if the first sensor fails.

[0065] According to a clause of the second aspect, the engine control unit is configured to determine a failure of the first sensor or the second sensor by comparing the output of the first sensor with the output of the second sensor during rotation of the superstructure relative to the substructure.

[0066] According to a clause of the second aspect, the tracked vehicle further includes an input device that can be activated by an operator of the tracked vehicle to input a directional switch request.

[0067] According to a clause of the second aspect, the output interface further includes an output device configured to emit an audible or optical signal to indicate to an operator of the tracked vehicle that a directional switch is requestable.

[0068] According to a clause of the second aspect, the electronic control unit is configured to detect whether at least a vehicle stability condition has been met and to emit a signal only if the vehicle stability condition has been met.

[0069] According to a clause of the second aspect, the tracked vehicle further includes a speedometer, and wherein the electronic control unit is configured to emit a signal only if the output of the speedometer indicates that the tracked vehicle is not moving faster than a predetermined maximum speed.

[0070] According to a clause of the second aspect, the electronic control unit is configured to emit a signal only if the tracked vehicle is in neutral or park.

[0071] According to a clause of the second aspect, the electronic control unit is configured to emit a signal only if the speed control mechanism indicates that the operator of the tracked vehicle has not requested the tracked vehicle to move forward or backward.

[0072] According to a clause of the second aspect, the tracked vehicle further includes an inclinometer, and wherein the electronic control unit is configured to emit a signal only if the output of the inclinometer indicates that the tracked vehicle is tilted less than a predetermined maximum tilt.

[0073] According to a clause of the second aspect, the transmission performs a directional switch on the tracked vehicle in response to detecting a directional switch request only after a signal has been emitted and at least the vehicle stability condition has also been met.

[0074] According to a clause of the second aspect, the output interface includes a first output device and a second output device, the first output device being configured to emit a signal to indicate to the operator of the tracked vehicle that a directional switch is requestable, the second output device being configured to emit a second signal to indicate that no directional switch is performed in the case where a directional switch request is detected after the first signal has been emitted but the vehicle stability condition is not met.

[0075] According to a clause of the second aspect, the first and second output devices include an illuminated instrument panel visual effect.

[0076] According to a clause of the second aspect, wherein the electronic control unit is configured to detect whether at least the vehicle operating condition has been met and to emit a signal only if the vehicle operating condition has also been met.

[0077] According to a clause of the second aspect, the tracked vehicle further includes a work implement activation lever, and wherein the vehicle operating condition includes the work implement activation lever being unlocked.

[0078] According to a clause of the second aspect, the threshold angular displacement is approximately 90 degrees.

[0079] According to a clause of the second aspect, the electronic control unit is configured to stop emitting a signal in the case where a relative angular displacement caused by rotation results in an angular displacement exceeding a second threshold angular displacement and no directional switch request has been detected after the signal has been emitted.

[0080] According to a clause of the second aspect, the transmission is configured to not perform a directional change of the tracked vehicle in response to the electronic control unit detecting a directional change request after it has stopped emitting the first signal.

[0081] According to a clause of the second aspect, the difference between the second threshold angular displacement and the first threshold angular displacement is about 180 degrees.

[0082] According to a clause of the second aspect, the electronic control unit is configured to detect a failure of a sensor for detecting the rotation of the superstructure of the tracked vehicle relative to the substructure of the tracked vehicle about an axis, and the electronic control unit is further configured to emit a signal via an output device to indicate that a failure has occurred.

[0083] According to a clause of the second aspect, the electronic control unit is further configured to, in response to the failure, alert the operator of the tracked vehicle that a directional change cannot be requested.

[0084] Additionally, a computer-readable storage medium including computer-readable storage instructions is provided, and the computer-readable storage instructions, when executed by a processor, cause the processor to perform the method defined in the second aspect.

[0085] According to the third aspect, a method is provided, which includes:

[0086] Detecting the rotation of the superstructure of the tracked vehicle relative to the substructure of the tracked vehicle about an axis;

[0087] Performing a directional change of the tracked vehicle in response to (i) the rotation resulting in a relative angular displacement exceeding a threshold angular displacement and (ii) receiving an operator-initiated directional change request.

[0088] According to the fourth aspect, a tracked vehicle is provided, which includes:

[0089] A vehicle body, which includes a substructure and a superstructure, and the superstructure is rotatable relative to the substructure about an axis;

[0090] An angle sensor for detecting the rotation of the superstructure relative to the substructure about an axis;

[0091] A first track assembly and a second track assembly, respectively mounted on opposite lateral sides of the vehicle body;

[0092] A prime mover;

[0093] An electronic control unit;

[0094] A transmission for controlling the directionality of the track assemblies based on the output of the electronic control unit;

[0095] The electronic control unit is configured to perform a directional switch of a tracked vehicle by responding to an operator-initiated directional switch request in response to the angular sensor having detected a relative angular displacement that exceeds a threshold angular displacement.

[0096] Additionally, a computer-readable storage medium including computer-readable storage instructions is provided, and the computer-readable storage instructions, when executed by a processor, cause the processor to execute the method defined in the third aspect.

[0097] According to a fifth aspect, a method is provided, which includes:

[0098] detecting an operator command for aligning an upper structure of a tracked vehicle relative to a lower structure of the tracked vehicle;

[0099] in response to detecting the operator command, applying a controlled rotation of the upper structure relative to the lower structure about an axis to align the upper structure relative to the lower structure at a predetermined relative angle.

[0100] According to a clause of the fifth aspect, the command is a first command, and the method further includes detecting a second operator command for rotating the upper structure of the tracked vehicle relative to the lower structure about an axis.

[0101] According to a clause of the fifth aspect, the method is executed by a processor of an electronic control unit, and the method further includes accessing a memory of the electronic control unit to obtain a predetermined relative angle.

[0102] According to a clause of the fifth aspect, the predetermined relative angle is selected from a first angle and a second angle, and the method further includes detecting a current relative angle between the upper structure and the lower structure, and selecting the predetermined relative angle as the first angle or the second angle according to the current relative angle.

[0103] According to a clause of the fifth aspect, the first and second angles are separated by 180 degrees.

[0104] According to a clause of the fifth aspect, the method further includes, before detecting the operator command, receiving an indication of a predetermined relative angle from an operator of the tracked vehicle and storing the predetermined relative angle in a memory.

[0105] According to a clause of the fifth aspect, the method further includes signaling that alignment has been achieved in response to the upper structure having been aligned relative to the lower structure at a predetermined relative angle.

[0106] According to a clause of the fifth aspect, the method further includes emitting at least one of an audible alarm and an optical alarm in response to detecting the operator command.

[0107] According to a clause of the fifth aspect, signaling that alignment has been achieved includes stopping emitting at least one of an audible alarm and an optical alarm.

[0108] According to a clause of the fifth aspect, signaling that alignment has been achieved includes reducing the angular velocity of the superstructure to a minimum when alignment has been achieved.

[0109] According to a clause of the fifth aspect, signaling that alignment has been achieved includes temporarily stopping the rotation of the superstructure when alignment has been achieved.

[0110] According to a clause of the fifth aspect, the method further includes: when alignment has been achieved, stopping the rotation of the superstructure and not responding to further detection of an operator command within a specific time period during and after signaling.

[0111] According to a clause of the fifth aspect, the operator command is a first operator command, the method further includes detecting a second operator command for rotating the superstructure relative to the substructure about an axis, and wherein once the second operator command has been continuously applied for a period of time after alignment, that period of time expires.

[0112] According to a clause of the fifth aspect, signaling that alignment has been achieved includes: when alignment has been achieved, emitting at least one of an audible alarm and an optical alarm to the operator of the tracked vehicle.

[0113] According to a clause of the fifth aspect, if an operator command is continuously received during and immediately after signaling, rotation of the superstructure relative to the substructure continues after signaling such that the superstructure is no longer aligned with the substructure at a predetermined relative angle.

[0114] According to a clause of the fifth aspect, the operator command is a first operator command, the method further includes detecting a second operator command for rotating the superstructure relative to the substructure about an axis, and wherein detecting the second operator command includes detecting that the operator of the tracked vehicle has applied and continues to apply at least a specific force to a first input controller of the tracked vehicle.

[0115] According to a clause of the fifth aspect, detecting the first operator command includes detecting that the operator of the tracked vehicle has applied and continues to apply at least a specific force to a second input controller of the tracked vehicle.

[0116] According to a clause of the fifth aspect, detecting the first operator command includes detecting that the operator of the tracked vehicle has applied and continues to apply at least a specific force to a second input controller of the tracked vehicle while applying at least that specific force to a first input controller of the tracked vehicle.

[0117] According to a clause of the fifth aspect, detecting a first operator command includes detecting that an operator of a tracked vehicle has recently applied at least one specific force to a second input controller of the tracked vehicle, wherein the superstructure is autonomously rotated relative to the substructure about an axis to align the superstructure with the substructure at a predetermined relative angle.

[0118] According to a clause of the fifth aspect, detecting a first operator command includes detecting that an operator of a tracked vehicle has recently applied at least the specific force to a second input controller of the tracked vehicle while applying at least one specific force to a first input controller of the tracked vehicle, wherein the controlled rotation of the superstructure relative to the substructure about an axis to align the superstructure with the substructure at a predetermined relative angle occurs only if at least the specific force is continuously applied to the first input controller of the tracked vehicle.

[0119] According to a clause of the fifth aspect, applying a controlled rotation of the superstructure relative to the substructure about an axis to align the superstructure with the substructure at a predetermined relative angle includes autonomously rotating the superstructure relative to the substructure about the axis to align the superstructure with the substructure at the predetermined relative angle.

[0120] According to a clause of the fifth aspect, applying a controlled rotation of the superstructure relative to the substructure about an axis to align the superstructure with the substructure at a predetermined relative angle includes restricting the angular displacement of the superstructure relative to the substructure about the axis according to an angular displacement limit curve.

[0121] According to a clause of the fifth aspect, the angular displacement limit curve indicates the maximum rate of angular displacement according to the angular distance relative to the predetermined relative angle.

[0122] According to a clause of the fifth aspect, the method is executed by a processor and further includes accessing a memory to obtain the angular displacement limit curve.

[0123] According to a clause of the fifth aspect, the method further includes stopping restricting the angular displacement in response to detecting that no operator command is applied.

[0124] According to a clause of the fifth aspect, the command is a first operator command, the method further includes detecting a second operator command for rotating the superstructure relative to the substructure about an axis, and wherein detecting the second operator command includes detecting that an operator of the tracked vehicle has applied and continues to apply at least one specific force to a first input controller of the tracked vehicle.

[0125] According to a clause of the fifth aspect, detecting a first operator command includes detecting that an operator of the tracked vehicle has applied and continues to apply at least a specific force to a second input controller of the tracked vehicle, and wherein detecting non-application of the first operator command includes detecting that the operator has not applied at least the specific force to the second input controller of the tracked vehicle.

[0126] According to a clause of the fifth aspect, detecting a first operator command includes detecting that an operator of the tracked vehicle has applied and continues to apply at least the specific force to a second input controller of the tracked vehicle while applying at least the specific force to a first input controller of the tracked vehicle, and wherein detecting non-application of the first operator command includes detecting that the operator has not applied at least the specific force to the second input controller of the tracked vehicle or the operator has not applied at least the specific force to the first input controller of the tracked vehicle.

[0127] According to a clause of the fifth aspect, detecting a first operator command includes detecting that an operator of the tracked vehicle has recently applied at least a specific force to a second input controller of the tracked vehicle, wherein autonomous controlled rotation of the superstructure relative to the substructure about an axis to align the superstructure relative to the substructure at a predetermined relative angle.

[0128] According to a clause of the fifth aspect, the command is a first operator command, the method further includes detecting a second operator command to rotate the superstructure relative to the substructure about an axis, and further includes interrupting rotation of the superstructure relative to the substructure about the axis in response to detecting non-application of the second operator command.

[0129] According to a clause of the fifth aspect, detecting a second operator command includes detecting that an operator of the tracked vehicle has applied and continues to apply at least a specific force to a first input controller of the tracked vehicle, and wherein detecting non-application of the second operator command includes detecting that the operator has not applied at least the specific force to the first input controller of the tracked vehicle.

[0130] According to a clause of the fifth aspect, detecting a first operator command includes detecting that an operator of the tracked vehicle has applied and continues to apply at least a specific force to a second input controller of the tracked vehicle.

[0131] According to a clause of the fifth aspect, detecting a first operator command includes detecting that an operator of the tracked vehicle has applied and continues to apply at least a specific force to a second input controller of the tracked vehicle while applying at least the specific force to a first input controller of the tracked vehicle.

[0132] According to a clause of the fifth aspect, detecting a first operator command includes detecting that an operator of a tracked vehicle has recently applied at least one specific force to a second input controller of the tracked vehicle, wherein the superstructure is autonomously and controllably rotated relative to the substructure about an axis to align the superstructure relative to the substructure at a predetermined relative angle.

[0133] According to a clause of the fifth aspect, detecting a first operator command includes detecting that an operator of a tracked vehicle has recently applied at least one specific force to a second input controller of the tracked vehicle while applying at least one specific force to a first input controller of the tracked vehicle, wherein the superstructure is controllably rotated relative to the substructure about an axis to align the superstructure relative to the substructure at a predetermined relative angle only if the at least one specific force continues to be applied to the first input controller of the tracked vehicle.

[0134] According to a clause of the fifth aspect, the axis is perpendicular to the travel plane of the tracked vehicle.

[0135] According to a clause of the fifth aspect, after alignment is achieved, the tracked vehicle is allowed to travel in a forward or backward direction along the travel plane.

[0136] According to a clause of the fifth aspect, before and during at least a part of the controlled rotation, the tracked vehicle is prevented from traveling in a forward or backward direction along the travel plane.

[0137] According to the sixth aspect, there is provided a tracked vehicle comprising:

[0138] a vehicle body including a substructure and a superstructure, the substructure being rotatable relative to the superstructure about an axis;

[0139] a motor for rotating the superstructure relative to the substructure;

[0140] a first track assembly and a second track assembly, respectively mounted on opposite sides of the vehicle body;

[0141] an operator interface for allowing an operator of the tracked vehicle to input an operator command;

[0142] an electronic control unit configured to:

[0143] detect an operator command to align the superstructure relative to the substructure;

[0144] in response to detecting the operator command, control the operation of the motor to align the superstructure relative to the substructure at a predetermined relative angle.

[0145] According to a clause of the sixth aspect, the tracked vehicle further includes a sensor for detecting the rotation of the superstructure relative to the substructure about an axis, and the electronic control unit is configured to control the operation of the motor based on the output of the sensor.

[0146] According to a clause of the sixth aspect, the command is a first command, and the electronic control unit is further configured to detect a second operator command to rotate the superstructure relative to the substructure.

[0147] In addition, a computer-readable storage medium including computer-readable storage instructions is provided, and the computer-readable storage instructions, when executed by a processor, cause the processor to execute the method defined in the sixth aspect.

[0148] According to the seventh aspect, a tracked vehicle is provided, which includes:

[0149] A vehicle body including a substructure and a superstructure, the superstructure being rotatable relative to the substructure about an axis;

[0150] A motor for rotating the superstructure relative to the substructure;

[0151] A first track assembly and a second track assembly, respectively mounted on opposite sides of the vehicle body;

[0152] An inclinometer configured to detect the inclination of the tracked vehicle and output a signal indicating the inclination; and

[0153] An electronic control unit configured to limit the rotational speed of the superstructure relative to the substructure according to the output of the inclinometer. Description of the Drawings

[0154] Figure 1A And 1B Are respectively a front view and a side view of a tracked vehicle having a superstructure and a substructure according to an exemplary non-limiting embodiment.

[0155] Figure 1C Is Figure 1A And Figure 1B A schematic top view of the tracked vehicle of.

[0156] Figure 1D Is Figure 1A And Figure 1B A side view of the cab of the tracked vehicle of.

[0157] Figure 2 Is a block diagram showing an engine control unit (ECU) for controlling a motor that rotates the superstructure of a tracked vehicle relative to the substructure.

[0158] Figure 3It is a top view of the upper structure showing the rotation angle θ with respect to the lower structure.

[0159] Figure 4 It is a block diagram conceptually showing routines (including a drive routine and a direction selection routine) stored in the code memory of the ECU and a direction variable stored in the data memory of the ECU.

[0160] Figure 5 It is a block diagram showing the input and output of a drive routine executable by the processor of the ECU.

[0161] Figure 6 It is a flowchart showing the operation of a direction selection routine executable by the processor of the ECU.

[0162] Figure 7 and 8 is similar to Figure 6 but combines the verification of additional conditions according to two variants of the direction selection routine.

[0163] Figure 9 and Figure 10 are block diagrams showing the input and output of a standby buzzer routine and a light color routine executable by the processor of the ECU, respectively.

[0164] Figure 11 It shows a pictogram notifying the operator of the tracked vehicle that the direction of the tracked vehicle is switchable.

[0165] Figure 12 It is a block diagram showing the input and output of an intelligent alignment routine executable by the processor of the ECU.

[0166] Figure 13 It shows a pictogram notifying the operator of the tracked vehicle that the intelligent alignment option has been selected.

[0167] Figure 14 It shows an angular displacement limit curve for the intelligent alignment routine.

[0168] Figure 15 It is a perspective view of a transmission including a hydrostatic motor, a hydrostatic pump, and an ECU.

[0169] Figure 16 It is a schematic diagram of an embodiment of a tracked vehicle having an upper structure and a lower structure, where a prime mover is mounted to the lower structure. Detailed Description

[0170] Reference Figure 1A 、 1B, 1C and 1D, illustrate a tracked vehicle 10 according to a non - limiting embodiment of the present invention. The tracked vehicle 10 includes a vehicle body having a lower structure 26 and an upper structure 32, and the upper structure 32 is rotatable relative to the lower structure 26 about an axis 8. A vertical passage 16 with bearings extends between the upper structure 32 and the lower structure 26 and can allow cables, tubes containing hydrostatic oil, and (optionally) a thermometer to pass through. Various bearing types (including but not limited to slewing bearings) can be used to allow the upper structure 32 to rotate relative to the lower structure 26. The cab 18 is mounted to the upper structure 32 and moves with the upper structure 32 when the upper structure 32 undergoes an angular displacement from an initial angular position. The motor 100 is configured to controllably rotate the upper structure 32 relative to the lower structure 26 based on an output from an engine control unit (ECU) 60. The motor 100 can be anchored to the upper structure 32 and can engage the lower structure 26, or the motor 100 can be anchored to the lower structure 26 and can engage the upper structure 32; in either case, relative movement of the upper and lower structures is achieved due to the force exerted by the motor 100.

[0171] In the present embodiment, two track assemblies 31X, 31Y are mounted to the vehicle body. Specifically, there is one track assembly on each of two opposite lateral sides of the lower structure 26. In other embodiments, there can be more than two track assemblies. A particular track assembly (e.g., track assembly 30X) can include a drive wheel 22, an idler wheel 28, and one or more support wheels 24 surrounded by an endless track 30X. The track can be any suitable track, such as a rubber track, including but not limited to a metal - embedded rubber track (MERT). In the illustrated embodiment, the tracks are designated as X and Y.

[0172] The prime mover 12 is mounted on the vehicle body. In the illustrated Figure 1A , 1B and 1C embodiments, the prime mover 12 is mounted to the upper structure 32. However, this does not exclude mounting the prime mover as Figure 16 shown to the lower structure 26. The prime mover 12 can be an engine, such as an internal combustion (e.g., diesel or gasoline) engine or an electro - hydraulic motor, which are several non - limiting possibilities listed. The transmission 1610 transmits power from the prime mover 12 to the track assemblies 31X, 31Y, e.g., to the drive wheels 22 of each track assembly. In one embodiment, the transmission 1610 can be a hydrostatic transmission, as Figure 15As shown. Specifically, the hydrostatic drive includes one or more hydrostatic pumps 34X coupled to a prime mover 12. The hydrostatic pump 34X delivers a controllable amount of hydrostatic fluid flow to a hydrostatic motor 14X mounted to one of the drive wheels 22. There may be two hydrostatic pumps independently supplying respective hydrostatic motors 14X, 14Y to independently control the movement of tracks 30X and 30Y. Each hydrostatic pump is configured to regulate the amount of motive power sent to its corresponding track assembly 31X, 31Y and the rotational direction of the corresponding drive wheel 22 in accordance with a respective control signal received from the ECU 60. In Figure 16 In another embodiment conceptually shown in

[0173] Each drive wheel 22 can rotate in each of two opposite directions (clockwise and counterclockwise when looking outwards from the tracked vehicle 10), thereby causing the corresponding endless tracks 30X, 30Y to move, thus propelling the tracked vehicle 10 in various possible travel directions in a so-called "travel plane". Two such directions are opposite to each other and longitudinally aligned with the substructure 26. Although these two opposite travel directions may be referred to as "forward" and "backward", these terms may lose their meaning due to the possible symmetry used to control the track assemblies and due to the rotatability of the superstructure 32 (and cab 18) relative to the substructure 26 to which the track assemblies 31X, 31Y are attached. Thus, the two opposite directions in which the tracked vehicle 10 can travel when the same amount of motive power is applied to the two track assemblies 31X, 31Y (with matching rotational directions) are referred to as "A" and "B" (as shown). By making the amount of motive power applied between the two track assemblies different, the substructure 26 can be rotated about a central axis perpendicular to the travel plane, which will occur during a steering operation. It should be noted that the axis about which the superstructure 32 and the substructure 26 can rotate relative to each other generally can also be perpendicular to the travel plane of the tracked vehicle and may or may not correspond to the aforementioned central axis.

[0174] Additionally, in some embodiments, a work implement 20 can be mounted to the superstructure 32. In one example application (shown in Figure 1A 、 1BIn FIGS. 1B and 1C, the work implement 20 may include a tipping box mounted on the superstructure 32 behind the cab 18 in the longitudinal direction of the tracked vehicle 10. The tipping box may be controllably pivoted along a transverse axis (or more than one axis) to effectively unload its contents behind the tracked vehicle 10. In other exemplary applications, the work implement 20 may be an excavator bucket / dipper, an oil drill, a crane, etc., and / or may be mounted in front of the cab 18. The operation of the work implement 20 may be controlled by signals sent from the ECU 60, which receives instructions input by the operator of the tracked vehicle 10 at the work implement control center 48.

[0175] The cab 18 may provide a seat for the operator and, in some cases, may also accommodate one or more passengers. The cab 18 includes various control input devices for allowing the operator to control the movement and operation of the tracked vehicle 10 and the work implement 12. Specifically, the control input devices may include a shifter 50 through which the operator may input the selected relative direction (forward / ahead, reverse) of the tracked vehicle 10. The control input devices may also include an accelerator 52 (e.g., a pedal, a joystick, a lever, or other device) through which the operator may input a requirement for more or less movement in the selected relative direction (also referred to as a movement demand input device). In some embodiments, the accelerator 52 is in the form of an "infinitely variable" pedal positioned such that the angle of the pedal is directly related to the requirement for speed, and the pedal is biased towards an initial position where the demand is for zero movement, i.e., lifting the foot off the pedal causes the tracked vehicle to decelerate until it stops. Optionally, a brake pedal or other mechanism may be provided through which the operator may input a deceleration requirement. In other embodiments, the shifter 50 may include features for the operator to select gears (low, high, neutral, first gear, second gear, etc.).

[0176] The control input devices may additionally include a steering unit 40 (e.g., a steering wheel, a joystick, a scroll bar, a touch screen, a lever, etc.) through which the operator may input a requirement for turning the tracked vehicle 10 (i.e., changing the travel orientation of the substructure 26).

[0177] The control input devices may also include the aforementioned work implement control center 48 through which the operator may enable, disable, and / or control the use of the work implement 20. The work implement control center 48 may be partially integrated with the seat 44 on which the operator is seated. The control input devices may further optionally include a directional control input device 46 through which the operator may input a "directional switching request" as will be described later. The directional control input device 46 may be integrated with the work implement control center 48 as shown, although this need not be the case in all embodiments. Figure 1D shown integrated with the work implement control center 48, although this need not be the case in all embodiments.

[0178] Other control input devices not shown in the drawings may also be provided to control various other common aspects of the tracked vehicle 10 (such as ignition, radio, heating, seat adjustment, etc.).

[0179] A plurality of sensors 202 ( Figure 2 ) are also provided, which are configured to detect and / or measure various parameters of the tracked vehicle and send their outputs to the ECU 60. These sensors 202 may particularly include a tachometer 204, which infers the speed of the tracked vehicle by measuring the rotating components of the tracked vehicle. For example, the tachometer 204 may measure the rotational speeds of the hydrostatic motors 14X, 14Y, from which the speed of the tracked vehicle 10 can be calculated. Specifically, the average value of two readings of the rotational speeds of the two hydrostatic motors 14X, 14Y can be taken. Additionally, by way of several non-limiting examples, the plurality of sensors 202 may include an inclinometer 206 configured to measure the inclination of the tracked vehicle 10, an odometer 210 configured to measure the travel distance, a thermometer 208 configured to detect / measure the temperature of the engine oil or hydrostatic oil or the external temperature, etc.

[0180] The sensor 202 may further include an angle sensor 212, which is configured to detect / measure the rotation angle of the superstructure 32 relative to an initial angular position. The initial angular position can be arbitrarily selected, and as Figure 3 shown, in this case, the initial angular position is selected to be in the direction A. Therefore, the reading of the angle sensor 212 will be a value θ between -180 degrees and 180 degrees, which is taken with respect to the vector V pointing in the direction A. The angle sensor 212 is configured to provide its angular displacement reading to the ECU 60. The angle sensor 212 can be mounted to the superstructure 32 or the substructure 26, or can be partially mounted to both the superstructure 32 and the substructure 26. By way of two non-limiting examples, the angle sensor 212 can be implemented as an encoder or a potentiometer. An example of an encoder-based angle sensor is the type ST350R (or ST350R-H1-360-1-1-X-P) from SensorSystems SRL of Chiari, Italy, but various other encoder-based angle sensors may also be suitable. A potentiometer-based angle sensor can also be used.

[0181] The various control input devices and sensor outputs can be connected to the ECU 60, which processes them according to control algorithms to provide control over the movement and operation of the tracked vehicle 10, including driving the track assemblies 31X, 31Y and manipulating the work implement 20. Moreover, the ECU 60 issues a signal 220 for communicating various data end events to the operator of the tracked vehicle.

[0182] To this end, the cab 18 further includes an output interface for notifying the operator of various conditions of the tracked vehicle 10 and / or the working implement 20. Specifically, the output interface may include a dashboard 42. The dashboard 42 can display a plurality of visual effects (such as lights, icons, symbols, pictograms, etc.) that can be controlled (e.g., illuminated) by the ECU 60. The visual effects can convey various data and events, such as vehicle speed, engine speed (RPM), oil temperature, selected relative direction, fuel quantity, etc. Other data and events can be signaled by optical alarms, which will be introduced later. Additionally, one or more speakers (not shown) can be provided to signal data and events, such as a standby warning signal. Other data and events can be signaled by the speakers by means of audible alarms, which will be described later. The output interface can include other devices, such as a screen, a siren, and so on.

[0183] Reference Figure 2 , the ECU 60 can include a processor 64, a code memory 62, a data memory 68, a power supply 66 (which can extract power from an alternator (not shown)), an input interface 230, and an output interface 240. Additionally, the ECU 60 can include a network interface 250 and a network communication device 260, which allow communication with a network using wireless communication technologies. In one embodiment, the processor 64 is configured to execute computer-readable instructions stored in the control memory 62. The instructions encode a program (software) that, when executed by the processor, causes the processor 64 and / or the ECU 60 to perform various tasks or routines. Each routine controls certain functions of the tracked vehicle 10 based on specific control inputs, sensor outputs, and / or parameters stored in the data memory 68.

[0184] Reference Figure 4 , for example, the routines can particularly include a drive routine 402 that controls the power supply to the drive wheels 22 of the relative track assemblies 31X, 31Y and a direction selection routine 404 that controls the directional parameters used by the drive routine 402. These two routines will be described in further detail below. Of course, other routines can be executed to control other aspects of the operation of the tracked vehicle 10 or the working implement 20, however, these do not need to be described in detail here.

[0185] Drive routine ( Figure 5 )

[0186] According to this routine, the processor 64 responds to the outputs from the shifter 50 (selected relative direction), the accelerator 52, the (optional) brake, and the steering unit 40 in order to provide instructions to a hydrostatic pump that controls the distribution of engine power to the hydrostatic motors 14X, 14Y connected to the track assemblies 31X, 31Y. Additionally, the processor 64 accesses the current "directionality" of the tracked vehicle 10. The current "directionality" can refer to a direction (in this case A or B): the tracked vehicle 10 will move in that direction in response to the operator's current movement requirements when the selected relative direction is "forward" (e.g., stepping on the accelerator 52 when the shifter 50 is set to "forward gear").

[0187] In one example, the current directionality can be represented as a global variable DIRECTIONALITY 420 stored in the memory 68 and modifiable by a directionality selection routine 404 as described below. In one embodiment, DIRECTIONALITY can have a value of 0 or 1, where "DIRECTIONALITY = 0" can indicate that the tracked vehicle 10 will move in direction A in response to the operator's movement requirements when the shifter 50 is set to "forward gear", and "DIRECTIONALITY = 1" can indicate that the tracked vehicle 10 will move in direction B in the same situation.

[0188] In another embodiment, DIRECTIONALITY 420 can be an integer indicating the number of times a directionality switch has occurred, such that an even value of DIRECTIONALITY 420 can indicate that the tracked vehicle 10 will move in direction A in response to the operator's movement demands when the shifter 50 is set to "forward gear", and an odd value of DIRECTIONALITY 420 can correspond to movement in direction B in the same situation.

[0189] Thus, according to the drive routine 402 (with the binary global variable DIRECTIONALITY 420 as described above), consider the response to the operator's (perceived) forward movement requirement when facing direction A (i.e., engaging (e.g., stepping on) the accelerator 52) with the shifter 50 in "forward gear" and DIRECTIONALITY 420 having a value of 0. This should cause the tracked vehicle 10 to move in direction A. In this case, the processor 64 instructs the hydrostatic pump 34X such that the drive wheel 22 of the track 30X rotates counterclockwise (when viewed from the outside of the tracked vehicle 10), and the drive wheel 22 of the track 30Y rotates clockwise (when viewed from the outside of the tracked vehicle 10). Thus, the movement of the tracked vehicle 10 as perceived by the operator corresponds to the selected relative direction ("forward").

[0190] The amount of power that the processor 64 commands the transmission 1610 (i.e., the hydrostatic pumps 34X, 34Y) to supply to each drive wheel hydrostatic motor 14X, 14Y can depend on the output of the accelerator 52, and the relative proportion of the power that the processor 64 commands the transmission 1610 to supply to each drive wheel hydrostatic motor 14X, 14Y can depend on the output of the steering unit 40. Of course, when the pressure on the accelerator 52 is released (or when the brakes are applied appropriately), the processor 64 will command the transmission 1610 to reduce the amount of power transmitted to the motors 14X, 14Y coupled to the drive wheels 22.

[0191] On the other hand, now consider the response to the operator's forward movement requirement when facing direction B (i.e., engaging (e.g., stepping on) the accelerator 52) with the shifter 50 in the "forward" gear and the DIRECTIONALITY 420 having an opposite value of 1. This should cause the tracked vehicle 10 to move in direction B. In this case, the processor 64 commands the transmission 1610 such that the drive wheels 22 of the track 30X rotate in a clockwise direction (when viewed from the outside of the tracked vehicle 10), and the drive wheels 22 of the track 30Y rotate in a counterclockwise direction (when viewed from the outside of the tracked vehicle 10). Here, again, since the operator is facing direction B, the movement of the tracked vehicle 10 as perceived by the operator corresponds to the selected relative direction ("forward").

[0192] Conversely, in the case where the shifter 50 is in the "reverse" gear and the DIRECTIONALITY 420 has a value of 0, the operator's backward movement requirement when facing direction A (i.e., engaging (e.g., stepping on) the accelerator 52) should cause the tracked vehicle 10 to move in direction B, and in the case where the shifter 50 is in the "reverse" gear and the DIRECTIONALITY 420 has a value of 1, the operator's backward movement requirement when facing direction B (i.e., engaging (e.g., stepping on) the accelerator 52) should cause the tracked vehicle 10 to move in direction A. In both cases, the movement of the tracked vehicle 10 as perceived by the operator corresponds to the selected relative direction ("backward").

[0193] Directionality selection routine ( Figure 6 )

[0194] According to this routine, in step 610, the processor 64 monitors the output of the angle sensor 212 and continuously compares it with a threshold angular displacement that depends on the value of DIRECTIONALITY 420. For example, when DIRECTIONALITY 420 has a first value, the threshold angular displacement can be 0 degrees, while when DIRECTIONALITY 420 has a second value, the threshold angular displacement can be 180 degrees. The output of the angle sensor 212 indicates the angular displacement relative to the initial angular position, such as a vector pointing in direction A (note, however, that this is only chosen for convenience and is not the case in every embodiment). Optionally and equivalently, the threshold angular displacement can be kept constant, and the readings obtained from the angle sensor can either not be adjusted or be adjusted by 180 degrees, depending on the value of DIRECTIONALITY 420.

[0195] Also note that the superstructure 32 can rotate bidirectionally relative to the substructure 26, and the output of the angle sensor 212 can be compared with a range defined by a lower threshold (negative 90 degrees) and an upper threshold (positive 90 degrees); alternatively, the magnitude (absolute value) of the output of the angle sensor 212 can be compared with a single threshold (e.g., 90 degrees). In step 620, if the magnitude of the output of the angle sensor 212 is not greater than the threshold angular displacement (e.g., 90 degrees), the processor returns to step 610, but if the magnitude of the output of the angle sensor 212 exceeds the threshold angular displacement, this means that the cab 18 has swung more in the direction that the operator would perceive as "backward" than in the direction that he or she would perceive as "forward". In that case, the processor proceeds to step 630 and causes a signal to be issued via the output interface 260 to indicate that a directional switch request is available.

[0196] Specifically, and with reference to Figure 11 , the processor 64 can cause the pictogram 1100 to light up on the dashboard 42 to signal to the operator that he or she can now request to switch the directionality (turn it around) of the tracked vehicle 10. To this end, in one embodiment, the processor 64 proceeds to step 640, in which the processor 64 waits for an operator input of a directional switch request by enabling the directionality control input device 46. The directionality control input device 46 can take the form of a separate dedicated button, an integrated device networked / paired with the ECU 60 or a multifunctional button on the touchscreen of a smart phone, a microphone for receiving voice commands, etc.

[0197] In another embodiment, it should be understood that step 630 is optional and the processor 64 can continue to wait in step 640 for an operator-initiated directional switching request without explicitly alerting the operator that such a switch is available. This would require the operator to keep track of the relative angle of the superstructure 32 and the substructure 26 in order to know when a directional switching request will be honored and when not.

[0198] In yet another embodiment, instead of waiting in step 640 for the operator to input a directional switching request by enabling the directional control input device 46, the processor 64 automatically generates an internal directional switching request itself. This can be done under the condition that the operator has previously indicated through the control input device and as recorded by the processor 64 that an automatic switching mode has been requested. In yet another embodiment, the directional switching request is automatically generated only if the angular output magnitude exceeds a second threshold angular displacement. That is, manual switching is allowed at angles between the first and second angular displacements, where the operator can choose to command a directional switching request, but when the angle becomes too large (i.e., exceeds the second threshold angular displacement), the directional switching is generated internally without operator input.

[0199] Assuming that the directional switching request is manually input by the operator enabling the directional control input device 46 (as detected by the processor 64 in step 650) or has been generated internally by the processor 64 (in the automatic switching mode, possibly only when exceeding the second threshold angular displacement), the next step is step 660, whereby the processor 64 performs the directional switching of the tracked vehicle 10. This can be done by updating, incrementing, or switching the DIRECTIONALITY 420 used by the drive routine 402 previously described.

[0200] Thus, if before step 660 the tracked vehicle 10 is moving in direction A in response to an operator's request to move forward (e.g., pressing the accelerator pedal 52 when the tracked vehicle is in the "forward gear"), then after step 660, the tracked vehicle 10 will now move in direction B in response to an operator's request to move forward (e.g., pressing the accelerator pedal when the tracked vehicle 10 is in the "forward gear"); and vice versa.

[0201] In other words, before performing the directional switch, the track assembly is controlled to move in the first direction in response to the operator's requirement for the tracked vehicle to move forward and to move in the second direction opposite to the first direction in response to the operator's requirement for the tracked vehicle to move backward; while after performing the directional switch, the track assembly is controlled to move in the second direction in response to the operator's requirement for the tracked vehicle to move forward and to move in the first direction in response to the operator's requirement for backward movement. The first and second directions may be opposite to each other.

[0202] It should be appreciated that the pictogram 1100 caused to be illuminated on the dashboard 42 in step 630 may be extinguished in response to receiving a directional switch request in step 650 or after performing the directional switch in step 660. A signal (e.g., an audible sound) under the control of the ECU 60 may be emitted via the speaker to indicate that the directional switch has been initiated or has successfully occurred.

[0203] At this time, i.e., after performing step 660, the processor 64 returns to step 610, where the processor 64 again continues to monitor the output of the angle sensor 212 and continuously compares the output magnitude of the angle sensor 212 with the threshold angular displacement. However, due to the new value of DIRECTIONALITY 420, the threshold angular displacement should now be adjusted by 180 degrees (e.g., now -90 degrees) or the threshold angular displacement may remain the same as before (at 90 degrees) and the readings obtained from the angle sensor may be adjusted by 180 degrees.

[0204] Then, in step 620, if the output magnitude of the angle sensor 212 exceeds the (new) threshold angular displacement, this means that the cab 18 has swung again in the direction that the operator currently perceives as the backward direction. In that case, the processor 64 proceeds to step 630 and causes a signal to be emitted via the output interface 260 to indicate that the directional switch is again requestable. Then, the processor 64 proceeds to step 640, where the processor 64 waits for the operator to input a directional switch request via the directional control input device 46. Again assuming that the operator inputs a directional switch request (or an automatic one is generated) via the directional control input device 46, which is detected by the processor 64 in step 650, then in step 660, the processor 64 performs a second directional switch on the tracked vehicle 10. This can be accomplished by re-switching the DIRECTIONALITY global variable used by the drive routine 402 to restore its value prior to the previous execution of step 660 described above.

[0205] Thus, if the tracked vehicle 10 moves in direction A in response to an operator's request to move forward (e.g., pressing the accelerator pedal 52 when the tracked vehicle 10 is in "drive") before the first execution of step 660, then after the second execution of step 660, the tracked vehicle 10 will also move in direction A in response to an operator's request to move forward (e.g., pressing the accelerator pedal 52 when the tracked vehicle 10 is in "drive"). This is because two (or more generally an even number of) directionality switches occur during this period. A signal (e.g., an audible alert that may be different from a previously emitted signal) can be generated to indicate that a directionality switch has occurred again.

[0206] Accordingly, it should be understood that if the "original" factory setting of the DIRECTIONALITY 420 variable causes an operator's request to move "forward" to result in the tracked vehicle 10 moving in direction A, then this will be the case after each even-numbered directionality switch. On the other hand, after each inserted (odd-numbered) directionality switch, an operator's request to move "forward" causes the tracked vehicle 10 to move in direction B (and an operator's request to move "backward" causes the tracked vehicle 10 to move in direction A).

[0207] Those skilled in the art will understand that monitoring whether the current value of DIRECTIONALITY 420 is indeed the same as the factory setting and displaying that fact (or difference) on the instrument panel 42 is within the scope of the present invention. Additionally, the number of times a directionality switch has been performed can be monitored by the processor 64 and displayed via an output device, such as via a digital readout on the instrument panel 42. These additional instrument panel features can complement the directionality selection routine 404.

[0208] Furthermore, the processor 64 can permanently store the factory setting of the DIRECTIONALITY 420 global variable in memory. Also, when starting / turning on the tracked vehicle 10 based on this information and an indication of whether the superstructure 32 has rotated beyond a threshold angular displacement and whether the cab 18 is facing the same way as at the factory, the current setting of DIRECTIONALITY 420 can be cancelled. Similarly, the processor 64 can emit a signal indicating whether the current value of DIRECTIONALITY 420 is different from the factory setting. This can allow the operator to know that the superstructure 32 needs to be repositioned relative to the substructure 26 at the end of a shift or before turning off the tracked vehicle 10.

[0209] Those skilled in the art will understand that in order to perform a directional switch, one or more additional conditions may need to be met. These additional conditions may include vehicle stability conditions and / or vehicle operating conditions. An example of a vehicle stability condition may be that the speed of the tracked vehicle 10 (e.g., as reported by the rotational speed sensor 204 or other speedometer) needs to be zero or below a specific threshold maximum. Another example of a vehicle stability condition may be that the tracked vehicle 10 is parked or in neutral. Yet another example of a vehicle stability condition may be that the accelerator pedal 52 is not depressed and / or the brake pedal is depressed. An example of a vehicle operating condition may be that the work implement 20 has been enabled by activating the work implement start lever that forms part of the work implement control center 48.

[0210] The requirement to meet one or more additional conditions can be integrated into the directional selection routine 404 in a variety of ways. For example, the Figure 7 flowchart in shows that additional conditions (step 710) need to be met before step 630 (i.e., before signaling via the output interface that a direction switch is requestable). In another example, the Figure 8 flowchart in shows that additional conditions need to be met before performing a directional switch in step 660 and even before the operator inputs a directional switch request in step 650, such that if the operator inputs a directional switch request in step 650 without the additional conditions being met (step 810), this will result in an alarm (e.g., an audible or visual alarm) being issued in step 820 and no directional switch occurring (of course, until the additional conditions are met). That is, although there is already a request for a directional switch, the alarm signals that the directional switch has not been performed.

[0211] It should be further understood that if the angle sensor 212 detects at some point in time that the output magnitude of the angle sensor 212 has fallen below 90 degrees before the operator has input a directional switch request (which may be due to a return to the original orientation of the superstructure 32 or due to over-rotation beyond 270 degrees, or the second threshold angular displacement and the first threshold angular displacement being shifted by 180 degrees), then the opportunity to request a directional switch is withdrawn. For example, if a pictogram is displayed on the dashboard 42 to indicate that the output magnitude of the angle sensor 212 is greater than 90 degrees, then the pictogram can stop being displayed on the dashboard 42. Thus, if a directional switch request is received once the angle sensor detects that the output magnitude of the angle sensor 212 has fallen below 90 degrees, the processor 64 will not cause the directional switch to be performed.

[0212] In a further variation, if there are additional conditions that must be met (such as one or more stability conditions and / or one or more operating conditions), this fact can be communicated to the operator separately. For example, the processor 64 can execute a separate routine to monitor whether the additional conditions are met, thereby causing a separate output signal (such as a second visual effect or an audible alarm) to be issued via the output interface to provide the operator of the tracked vehicle 10 access to the status of the additional conditions. In yet another variation, the signal issued in step 30 can have two "state" values, one indicating that the additional conditions are not met and the other indicating that the additional conditions have been met (and thus indicating that the directional change request will be accepted). This will assist the operator in evaluating whether to even consider requesting a directional change.

[0213] Those skilled in the art will further understand that certain other functions of the tracked vehicle 10 may also be affected by the rotation of the superstructure 32 beyond a threshold angular displacement. For example, the tracked vehicle 10 can also include a backup buzzer 110. In some embodiments, the backup buzzer 110 can be a speaker that emits a certain specific sound when instructed by the ECU 60. The processor in the ECU 60 can operate a routine (e.g., computer-readable instructions encoding the backup buzzer routine and that can be stored in the code memory 62) to determine when to issue a control signal to the backup buzzer 110 to cause the backup buzzer 110 to output its characteristic sound. To this end, Figure 9 A set of the output of the angle sensor 212 and the requested directionality (i.e., forward or backward) from the shifter 50 is shown. The backup buzzer 110 can be activated based on the values collected.

[0214] For example, in the case where the shifter 50 indicates that the operator has requested forward movement (by putting the engine in the drive state), the backup buzzer 110 will sound when the output of the angle sensor 212 has exceeded the threshold angular displacement (which will be cancelled depending on the global variable DIRECTIONALITY 420), because this means that the tracked vehicle 10 will sense backward movement by stepping on the accelerator 52. Similarly, in the case where the shifter indicates that the operator has requested backward movement (by putting the engine in the reverse state), the backup buzzer 110 will sound until the output of the angle sensor 212 has exceeded the threshold angular displacement, at which point it will stop sounding. This is because even though there is a requirement for backward movement, the superstructure 32 has been rotated excessively and the operator senses forward movement. Thus, note that the operation of the backup buzzer 110 does not depend on the value of DIRECTIONALITY 420. Instead, the value of DIRECTIONALITY affects the result of measuring whether the output of the angle sensor 212 has exceeded the threshold angular displacement in step 910, because the result will be different for the two different directionality values.

[0215] In another example, it may be required that the tracked vehicle 10 have lights of a certain color to indicate the direction in which it is traveling and / or to illuminate the road ahead of it. For example, the color of a traditional headlight is light, and the traditional color of a taillight is red. However, the tracked vehicle 10 may move symmetrically in direction A or direction B, so whether it shows a headlight or a taillight is not a function of the ends of the tracked vehicle, but rather a function of the direction in which the cab 18 faces with respect to the movement of the tracked vehicle 10. Therefore, lights of two colors (separate bulbs or using LEDs with controllable wavelengths, etc.) can be provided at both ends in the longitudinal direction of the tracked vehicle. Then, referring Figure 10 , the processor can execute the light color routine. Specifically, when DIRECTIONALITY 420 is 0 and the output of the angle sensor 212 does not exceed the threshold angular displacement, the light pointing in direction A can be a headlight (light color), and the light pointing in direction B can be a taillight (red); however, when the output of the angle sensor 212 exceeds the threshold angular displacement, the colors of the lights can be reversed because now the operator is facing direction B and needs to illuminate the road ahead of him or her with light of a light color. Similarly, when DIRECTIONALITY 420 is 1 and the output of the angle sensor 212 does not exceed the threshold angular displacement, this means that the operator is facing direction B and thus the light pointing in direction B can be a headlight (light color) and the light pointing in direction A can be a taillight (red); here, again, when the output of the angle sensor 212 exceeds the threshold angular displacement, the colors of the lights can be reversed. Note that the aforementioned light switching function occurs regardless of whether a directional switch is requested or executed.

[0216] According to another embodiment of the present invention, the tracked vehicle provides at least partial automatic alignment of the superstructure 32 and the substructure 26 at a predetermined relative angle. This may be beneficial, for example, when an operator wishes to drive the tracked vehicle 10 on a road and needs to align the superstructure 32 and the substructure 26 beforehand.

[0217] To this end, one of the control input devices (e.g., provided by the work implement control center 48) can be a "smart alignment" input device through which an operator can input a command to align the superstructure 32 relative to the substructure 26. By way of several non-limiting possibilities, the smart alignment input device can be a physical button, switch, lever, or soft button. The smart alignment input device can be part of the steering unit 40 or the work implement control center 48. In other embodiments, the operator can input a command to align the superstructure 32 relative to the substructure 26 via a smartphone that communicates with the processor 64, so the smartphone serves as the smart alignment input device. The smart alignment input device sends its readings to the ECU 60 such that the ECU 60 can determine / detect when the operator desires the superstructure 32 to be at least partially automatically aligned relative to the substructure 26.

[0218] For example, a predetermined relative angle can be stored in the memory 68 and obtained by the processor 64 from the memory 68 during an initialization operation. Alternatively, the predetermined relative angle can be an operator control value, so one of the control input devices can allow the operator to input the predetermined relative angle (e.g., via a keyboard or dial or switch or smartphone). Moreover, there can be multiple candidate predetermined relative angles to choose from, including a pair of predetermined relative angles that are 180 degrees apart. In one particular non-limiting embodiment, the first predetermined relative angle is 0 degrees and the second predetermined angle is 180 degrees, each representing the superstructure 32 and the substructure 26 being parallel to each other, but these two different predetermined relative angles indicate that in one case the superstructure 32 "swings" a half turn. It should be understood that in this embodiment, the work implement 20 can be arranged on the superstructure 32, but the cab 18 can be arranged on the superstructure 32 or the substructure 26.

[0219] Smart alignment routine

[0220] According to this embodiment, the processor 64 of the ECU 60 executes the smart alignment routine now referenced Figure 12 and described. The processor 64 can initiate the smart alignment routine in response to the processor 64 detecting an operator command to rotate the superstructure 32 relative to the substructure 26 (e.g., based on an operator input at the work implement control center 48, whereby the operator can activate or apply at least a certain amount of force to a joystick, button, or other controller to express the intention to rotate the superstructure) and an operator command to align the superstructure 32 relative to the substructure 26 (e.g., based on an operator input at the work implement control center 48, whereby the operator can activate the smart alignment input device).

[0221] Accordingly, referring to Figure 13, once the intelligent alignment routine has been initiated, the pictogram 1300 can be displayed on the dashboard 42 in step 1210 to signal that the intelligent alignment option has been selected. In step 1220, the processor 64 monitors the command to rotate the superstructure 32 relative to the substructure 26 and the command to align the superstructure 32 relative to the substructure 26 to ensure that both commands continue to be provided by the operator and thus the superstructure 32 continues to rotate relative to the substructure 26. In one embodiment, if the operator is detected as continuously pressing a button or applying a force on the interface component, it can be detected that the commands are continuously provided. If any of these commands is released or stops being provided, the processor 64 exits the intelligent alignment routine and returns to normal control.

[0222] In step 1230, the output of the angle sensor 212 is collected by the processor 64 and compared with a predetermined relative angle. When there is a match between the output of the angle sensor 212 and the predetermined relative angle, in step 1240, the processor 64 can stop the operation of the motor (step 1250) and issue an output signal in step 1260. The output signal can be an optical alarm emitted via a visual effect on the dashboard 42, which can result in the same visual effect as described in the context of step 1210. Alternatively, the output signal can be an audible alarm emitted through a speaker. This signals to the operator that the alignment is complete, i.e., the superstructure 32 is aligned with the substructure 26 at a predetermined relative angle.

[0223] Once the alignment is complete, the operator may wish to stop the rotation of the motor 100, and as described above, this can be done by releasing the command to rotate the superstructure 32 relative to the substructure 26 or the command to align the superstructure 32 relative to the substructure 26. However, the operator's response may be delayed. For this reason, it is also within the scope of the present invention that the processor 64 ignores its command to continue rotating the superstructure for a short period (e.g., a few seconds) after the alignment has been achieved to give the operator an opportunity to respond by releasing the command to rotate the superstructure 32 relative to the substructure 26 and / or the command to align the superstructure 32 relative to the substructure 26.

[0224] In an alternative embodiment, the commands to rotate the upper structure 32 relative to the lower structure 26 and / or the commands to align the upper structure 32 relative to the lower structure 26 do not need to be provided continuously, but can be a one-time input (e.g., by pressing a button on the screen). Once these inputs are completed (alternatively, a command for a single combined purpose has been input as recognized by the ECU 60), the processor 64 will enter the intelligent alignment routine, but the processor 64 does not need to perform step 1220, i.e., the processor 64 does not need to monitor the commands to rotate the upper structure 32 relative to the lower structure 26 and the commands to align the upper structure 32 relative to the lower structure 26, because it is not necessary for both commands to continue to be provided by the operator. Accordingly, the rotation of the upper structure 32 relative to the lower structure 26 continues autonomously until there is a match between the output of the angle sensor 212 and the predetermined relative angle. This alternative embodiment can be considered fully automatic or "hands-free". In this alternative embodiment, to stop the rotation and / or exit the intelligent alignment routine, the operator can explicitly stop the rotation by inputting a "stop" command via one of the control input devices.

[0225] In another alternative embodiment, it can be understood that after the upper structure 32 is measured to be in a specific angular position relative to the lower structure 26 (and before the operator reacts), there is a non-zero time taken to stop the operation of the motor 100. Accordingly, the output of the angle sensor 212 can be collected by the processor and compared with an "offset angle", which is an angle slightly offset from the predetermined relative angle. When there is a match between the output of the angle sensor 212 and the offset angle, the processor 64 can stop the operation of the motor and issue the aforementioned output signal. In this alternative embodiment, the non-zero time taken to stop the operation of the motor 100 after the upper structure 32 is in the relative angular position detected as the offset angle is calibrated such that during this non-zero time, the upper structure 32 rotates by the difference between the predetermined relative angle and the offset angle. This may result in improved alignment (closer to the predetermined relative angle).

[0226] In another alternative embodiment, during the execution of the intelligent alignment routine, the maximum angular velocity of the upper structure 32 (relative to the lower structure 26) can be limited by the processor. For this purpose, Figure 14The angular displacement limit curve 1400 is shown, which indicates how the rotational speed (change in angular displacement over time) is limited by the current relative angle of the upper structure 32 and the lower structure 26 with respect to a predetermined relative angle. It can be seen that the angular displacement (rotational speed) is lower, i.e., more strictly limited, when the current relative angle is close to the predetermined relative angle compared to when the current relative angle is very different from the predetermined relative angle. This means that although the operator continuously applies a force to the control input device (such as a joystick, etc.) to rotate the upper structure 32 relative to the lower structure 26, the fact that the intelligent alignment routine has been input means that the processor 64 will apply a "deceleration" (to a minimum angular velocity that may be as low as zero) as the upper structure 32 approaches alignment with the lower structure 26 at the predetermined relative angle. Of course, Figure 14 This is merely a conceptual example of an angular displacement curve, and other curves are possible, including smoother and less smooth curves as well as curves that are asymmetric with respect to the predetermined relative angle. Of course, there may be other limitations on angular displacement for various reasons such as safety, which may override the limitations of the angular displacement curve.

[0227] In some embodiments, the manner of signaling an alert regarding intelligent alignment may be different from that described above. For example, an audible or optical alert may be issued when entering the intelligent alignment routine and may continue to be issued during the execution of the intelligent alignment routine, but then may stop being issued when alignment has been achieved and / or when the processor 64 exits the intelligent alignment routine.

[0228] It should be understood that for various reasons (such as safety), once the processor 64 enters the intelligent alignment routine, the forward or backward movement of the tracked vehicle 10 (or movement anywhere along the travel plane) may be disabled, although it may be enabled in certain situations (such as at low speeds).

[0229] Those skilled in the art will understand that the angle sensor may malfunction. In that case, the processor can detect that the angle sensor 212 has malfunctioned. For example, when the superstructure 32 rotates relative to the substructure 26 but the reading from the angle sensor 212 does not change or changes abnormally (which can be inferred based on the control signal provided to the motor 100), the processor can draw such a conclusion. In that case, the output of the angle sensor 212 is unreliable, and the processor 64 can stop providing the operator with any further opportunities to request a directional change, or can ignore any request for a directional change, because incorrect information may have been provided to the operator. In such a case, a backup angle sensor (not shown) can be relied upon. As an alternative, multiple angle sensors can always be used such that the combination (e.g., average value) of the output values of two or more angle sensors (whose outputs are found to be within a specific predetermined tolerance) is adopted as the actually measured angular displacement of the superstructure relative to its initial angular position. When one or more angle sensors are detected to malfunction, this can be signaled to the operator via an output interface (e.g., via one or more visual effects or audible alarms on the instrument panel 42). As an alternative or in addition, the processor 64 can cause a signal to be issued to alert the operator of the tracked vehicle 10 that a directional change and / or intelligent alignment cannot be requested. This can be done by adjusting the display of the pictograms on the instrument panel 42, which can typically be illuminated to signal that a directional change or intelligent alignment can be requested. In such a case, for example, "adjust" can mean causing the pictogram to flash or have a different color or be accompanied by an additional symbol (e.g., a warning symbol).

[0230] It should be further understood that the rotation of the superstructure relative to the substructure requires the motor 100 to exert a force, and this force may not be equal within the relative angular range between the upper and lower structures. This is especially true when the tracked vehicle is on an incline, because in some cases the motor needs to overcome gravity, while in other cases it needs to withstand gravity. Since the energy required to overcome or withstand gravity may stress the motor 100, and since the induced stress increases with the rotational speed of the upper and lower structures as well as the incline, it is also within the scope of the present invention to limit the rotational speed according to the incline of the tracked vehicle as measured by the inclinometer 206.

[0231] In addition, the limitation on the rotational speed of the upper structure relative to the lower structure can be controlled by various other parameters, such as the maximum or measured load of the working implement 20 and / or the relative dimensions of the working implement 20 (e.g., the maximum distance from a part of the working implement 20 to the axis about which the upper and lower structures rotate relative to each other). To determine the measured load, load sensors (such as load meters (not shown)) can be integrated into the working implement or can be added separately to the upper or lower structure of the tracked vehicle, and their readings are provided to the ECU 60.

[0232] Thus, a set of rules defining a rotational limit surface can be designed, which is a multivariable curve that indicates how the rotational speed (angular displacement over time) of the upper structure relative to the lower structure is limited by these various parameters, such as the inclination angle (see Figure 1B ) and the rotation angle θ (also see Figure 3 ).

[0233] One can envision the case where the working implement 20 is a tipping box. In this case, when the inclination angle is very high, only a slightly higher rotational speed is allowed at a low rotation angle θ, and the same principle applies to large inclination angles and high rotation angles. This is because stability exists only when the tipping box is "hanging" (in the sense of gravity). This means that although the operator continuously applies a force on the control input device (such as a joystick, etc.) to rotate the upper structure 32 relative to the lower structure 26, as the upper structure 32 rotates around the lower structure 26, the processor 64 will impose a limit on the angular velocity of the tipping box to avoid destabilizing the tracked vehicle 10 as the tipping box swings downward.

[0234] Those skilled in the art will understand that the processor 64 can execute additional routines. For example, the processor 64 can execute a routine whereby operator inputs via the working implement control center 48 can be ignored under certain low-temperature conditions to protect the slewing bearing. For this purpose, a thermometer 208 can be placed in the hydrostatic oil circuit of the vertical passage / slewing bearing 16, which allows the upper structure to rotate relative to the lower structure. The output of the thermometer is sent to the ECU. The processor 64 then detects the temperature measured by the thermometer, and if it is below a specific threshold (e.g., -18 °C or -20 °C), the motor is locked and the upper structure 32 is prevented from rotating relative to the lower structure 26. When the temperature rises above the threshold, the motor can be re-enabled.

[0235] Certain additional elements that may be required for the operation of certain embodiments are not described or shown because they are considered to be within the knowledge of those of ordinary skill in the art. In addition, certain embodiments may not have, may lack, and / or may function without any elements not specifically disclosed herein.

[0236] Any feature of any embodiment discussed herein can be combined with any feature of any other embodiment discussed herein in some implementation examples.

[0237] Although various embodiments and examples have been presented, this is for the purpose of description and not limitation of the present invention. Various modifications and enhancements will become apparent to those of ordinary skill in the art and are within the scope of the present invention as defined by the appended claims.

Claims

1. A method executed by a processor of an electronic control unit, comprising: - Detecting an operator command for aligning a superstructure (32) of a tracked vehicle (10) relative to a substructure (26) of the tracked vehicle (10); - Responsive to detecting the operator command, applying a controlled rotation of the superstructure (32) about an axis (8) relative to the substructure (26) to align the superstructure (32) relative to the substructure (26) at a predetermined relative angle, characterized in that: - Responsive to the superstructure (32) having been aligned relative to the substructure (26) at the predetermined relative angle, signaling that the alignment has been achieved; - Stopping the rotation of the superstructure (32) when the alignment has been achieved and not responding to further detection of an operator command for a specific period immediately after signaling.

2. The method according to claim 1, wherein, The operator command is a first operator command, and the method further includes detecting a second operator command for rotating the superstructure of the tracked vehicle about the axis relative to the substructure.

3. The method according to claim 1, further comprising accessing a memory (62) of the electronic control unit (60) to obtain the predetermined relative angle.

4. The method according to any one of claims 1-3, wherein, Signaling that the alignment has been achieved includes reducing the angular velocity of the superstructure (32) to a minimum when the alignment has been achieved.

5. The method according to any one of claims 1-3, wherein Signaling that the alignment has been achieved includes temporarily stopping the rotation of the superstructure (32) when the alignment has been achieved.

6. The method according to any one of claims 1-3, wherein, The operator command is a first operator command, and the method further includes detecting a second operator command for rotating the superstructure (32) about an axis (8) relative to the substructure (26), and wherein, once the second operator command has been applied for a period of time after alignment, that period expires.

7. The method according to any one of claims 1-3, wherein Signaling that the alignment has been achieved includes, when the alignment has been achieved, issuing at least one of an audible alarm and an optical alarm to an operator of the tracked vehicle.

8. The method according to claim 1, wherein Applying a controlled rotation of the superstructure (32) about an axis (8) relative to the substructure (26) to align the superstructure (32) relative to the substructure (26) at a predetermined relative angle includes autonomously rotating the superstructure (32) about the axis (8) relative to the substructure (26) to align the superstructure (32) relative to the substructure (26) at the predetermined relative angle.

9. The method according to claim 1, wherein Applying a controlled rotation of the superstructure (32) about an axis (8) relative to the substructure (26) to align the superstructure (32) relative to the substructure (26) at a predetermined relative angle includes restricting the angular displacement of the superstructure (32) about the axis (8) relative to the substructure (26) according to an angular displacement limit curve.

10. The method according to claim 1, wherein, The axis (8) is perpendicular to the travel plane of the tracked vehicle (10), and during at least a portion of the controlled rotation, the tracked vehicle (10) is prevented from traveling in a forward or backward direction along the travel plane.

11. The method according to claim 1 further comprises detecting a current relative angle between the upper structure and the lower structure, wherein, Selecting the predetermined relative angle as a first angle or a second angle according to the current relative angle between the upper mechanism and the lower structure.

12. A tracked vehicle, comprising: - A vehicle body, the vehicle body including a lower structure (26) and an upper structure (32), the upper structure being rotatable 360 degrees relative to the lower structure (26) about an axis (8); - A motor (100) for rotating the upper structure (32) relative to the lower structure (26); - A first crawler assembly (31X) and a second crawler assembly (31Y), which are respectively mounted on opposite lateral sides of the vehicle body; - An operator interface for allowing an operator of the tracked vehicle (10) to input operator commands; and - A processor (64) of an electronic control unit (60), the processor being configured to execute the method according to claim 1.

13. The crawler vehicle according to claim 12, wherein, The upper structure includes a cab (18) and a working implement (20) that are rotatable together about the axis.

14. The crawler vehicle according to claim 12, wherein, The operator interface includes a joystick and a smart alignment input.

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