Technical Field

[1] The present invention relates to a mobile robot. More particularly, the present invention relates to a mobile robot having jump function. Background Art

[2] With developments in robot technology, a mobile robot has been introduced, and a mobile robot may be applied in various fields. For example, various robots such as a cleaning robot, a surveillance robot, or other types of robots have been developed.

[3] In particular, a robot for performing missions such as guard and scouting has an advantage to be able to be placed in poor surroundings where it is difficult for a person to perform guard or scouting mission and to effectively perform various missions there.

[4] A robot should be able to move in various ground conditions having obstacles to perform guard or scouting mission, but there is a problem that the conventional mobile robot cannot effectively move in poor ground conditions. A mobile robot having jump function is required to perform missions in various surroundings.

[5] A mobile robot having jump function has been introduced, but a conventional mobile robot having jump function has poor jump power, or has poor controllability of jump direction or jump level. Disclosure of Invention Technical Problem

[6] The present invention has been made in an effort to provide a mobile robot which can realize jump function through simple structure and can effectively control jump direction or jump level. Technical Solution

[7] An exemplary mobile robot according to an embodiment of the present invention includes: a robot body; a pair of wheels rotatably connected to the robot body; a driving motor driving the pair of wheels so as to move the robot body; a link mechanism connected to the robot body so as to be elongated to the rear of the robot body and pivotally connected to the robot body so as to pivotally rotate toward the robot body; a spring elastically connecting the robot body and the link mechanism; and a link mechanism regulating unit applying power enabling the link mechanism to overcome elastic power of the spring to move toward the robot body to the link mechanism and subsequently removing the power applied to the link mechanism such that the link mechanism returns to its original state by elastic force of the spring, thereby generating power for jump.

[8] The link mechanism regulating unit may include: a motor mounted to the robot body; a first gear connected to the motor so as to be rotated by the motor and having a part where gear teeth are formed and a part where gear teeth are not formed; a second gear mounted to the robot body in a state of being engaged with the first gear such that the second gear is engaged with the part of the first gear where the gear teeth are formed so as to be rotated by the first gear and is freely rotatable in case of being exposed to the part of the first gear where the gear teeth are not formed; a wire reel connected to the second gear so as to rotate together with the second gear; and a wire connecting the wire reel and the link mechanism so as to be wound to the wire reel by rotation of the wire reel thereby urging the link mechanism to overcome the elastic force of the spring to pivotally rotate toward the robot body or so as to be unwound from the wire reel by free rotation of the wire reel thereby allowing the link mechanism to return its original position by the elastic force of the spring.

[9] The mobile robot may further include a ratchet connected to the first gear so as to rotate together with the first gear, and a ratchet hook connected to the ratchet, and wherein the ratchet and the ratchet hook are formed not to allow the first gear to rotate in a direction in which the wire is unwound from the wire reel.

[10] The link mechanism may be formed such that the robot body rotates rearward by weight of the link mechanism in case that the link mechanism is pivotally rotated toward the robot body.

[11] The mobile robot may further include a jump direction regulating pin rotatably connected to the robot body such that an outer end thereof can be extruded to the outside of the robot body, and a servomotor driving the jump direction regulating pin to rotate, and wherein the jump direction regulating pin is configured to face the ground in a state that the robot body is rotated rearward by the pivotal rotation of the link mechanism and to regulate rotation position of the robot body by rotation thereof.

[12] The mobile robot may further include an anti-fall-down bar configured to be extruded toward the front of the robot body so as to limit forward rotation of the robot body.

[13] The link mechanism may include: a first leg one end of which is connected to the spring and which is connected to the robot body to pivotally rotate around a first pivot point; a second leg which is connected to the robot body to pivotally rotate around a second pivot point; and a foot member which is pivotally connected to outer ends of the first leg and the second leg respectively.

[14] The spring may be connected to the first leg so as to be extended in response to pivot rotation of the first leg toward the robot body.

[15] The mobile robot may further include: an ultrasonic wave sensor mounted at a front side of the robot body and detecting distance to an obstacle ahead and generating a corresponding signal; a position sensitive detector (PSD) sensor mounted at a front side of the robot body and performing sensing toward an upper direction upward by a predetermined angle from a horizontal direction thereby detecting distance to an upper edge of an obstacle ahead thereof and generating a corresponding signal; and a controller calculating height of the obstacle on the basis of the signals of the ultrasonic wave sensor and the PSD sensor.

[16] The mobile robot may further include: a first photo sensor mounted at a front side of the robot body and detecting whether a front region apart by a predetermined distance is an empty space and generating a corresponding signal; a second photo sensor mounted at a front side of the robot body and detecting whether a front region farther than the front region detected by the first photo sensor is an empty space and generating a corresponding signal; and a controller controlling an operation of the driving motor on the basis of signals of the first photo sensor and the second photo sensor.

[17] The controller may control the driving motor such that rotation speed of the pair of wheels is decreased in case that the signal received from the second photo sensor indicates that the detected region is an empty space, and may control the driving motor such that the pair of wheels are arranged in a line in case that the signal received from the first photo sensor indicates that the detected region is an empty space.

[18]

[19]

Advantageous Effects

[20] According to the present invention, a mobile robot can have jump function by a simple structure and can freely control jump direction. Brief Description of Drawings

[21] FIG. 1 and FIG. 2 are perspective views of a mobile robot according to an embodiment of the present invention, respectively.

[22] FIG. 3 is a front view of a mobile robot according to an embodiment of the present invention.

[23] FIG. 4 is a side view of a mobile robot according to an embodiment of the present invention.

[24] FIG. 5 is a top plan view of a mobile robot according to an embodiment of the present invention.

[25] FIG. 6 is a bottom plan view of a mobile robot according to an embodiment of the present invention.

[26] FIG. 7 is a perspective view showing an inner structure of a mobile robot according to an embodiment of the present invention.

[27] FIG. 8 is a drawing showing connection between a first gear and a second gear of a mobile robot according to an embodiment of the present invention.

[28] FIG. 9 to FIG. 13 are drawings for explaining jump processes of a mobile robot according to an embodiment of the present invention. Best Mode for Carrying out the Invention

[29] Hereinafter, embodiments of the present invention will be explained with reference to the drawings.

[30] FIG. 1 and FIG. 2 are perspective views of a mobile robot according to an embodiment of the present invention respectively, FIG. 3 is a front view of a mobile robot according to an embodiment of the present invention, FIG. 4 is a side view of a mobile robot according to an embodiment of the present invention, FIG. 5 is a top plan view of a mobile robot according to an embodiment of the present invention, FIG. 6 is a bottom plan view of a mobile robot according to an embodiment of the present invention, and FIG. 7 is a perspective view showing an inner structure of a mobile robot according to an embodiment of the present invention.

[31] Referring to FIG. 1 to FIG. 6, a mobile robot according to an embodiment of the present invention includes a robot body 110. The robot body 110 serves as a frame to which various elements of a mobile robot are mounted and may be formed as a plurality of supporting plates and supporting structures.

[32] A pair of wheels 120 are rotatably connected to the robot body 110. For example, as shown in the drawing, the wheels 120 are connected to both sides of the robot body 110 to face each other. The mobile robot may move by rotation of the wheels 120.

[33] A driving motor 130 drives the pair of wheels 120. The pair of wheels 120 are driven by the driving motor 130 so that the robot body 110 can move.

[34] As shown in FIG. 7, the driving motor 130 may be mounted to the robot body 110.

At this time, the driving motor 130 may be provided as a pair for driving the wheels 120 respectively. Although not shown in the drawing, the driving motor 130 may be connected to the pair of wheels 120 by a power transmission device such as a gear, and power of the driving motor 130 may be transmitted to the pair of wheels 120 via the power transmission device.

[35] A link mechanism 140 is connected to the robot body 110. As shown in the drawings, the link mechanism 140 is connected to the robot body 110 so as to be elongated to the rear of the robot body 110.

[36] The link mechanism 140 is pivotally connected to the robot body 110 so as to pivotally rotate toward the robot body 110.

[37] At this time, the link mechanism 140 is configured such that the robot body 110 rotates rearward by weight of the link mechanism 140 when the link mechanism 140 is pivotally rotated toward the robot body 110. Further detailed description for the same will be made later while explaining jump function of the mobile robot.

[38] The link mechanism 140 includes a first leg 141, a second leg 142, and a foot member 143. As shown in the drawings, the first leg 141 and the second leg 142 may be provided as one at both sides of the robot body 110, respectively.

[39] FIG. 8 is a drawing showing connection between a first gear and a second gear of a mobile robot according to an embodiment of the present invention. As shown in FIG. 8, the first leg 141 is pivotally connected to the robot body 110 to pivotally rotate around a first pivot point 144, and the second leg 142 is connected to the robot body 110 to pivotally rotate around a second pivot point 145. At this time, as shown in FIG. 8, while the mobile robot is in a normal state, the second leg 142 may be arranged to locate under the first leg 141.

[40] The foot member 143 is pivotally connected respectively to outer end parts of the first leg 141 and the second leg 142. That is, the foot member 143 is pivotally connected to the first leg 141 by a third pivot point 146 and to the second leg 142 by a fourth pivot point 147.

[41] At this time, when the mobile robot is in a normal state, the first pivot point 144 may be positioned forward and above the second pivot point 145, and the third pivot point 146 may be positioned forward and above the fourth pivot point 147.

[42] Meanwhile, as shown in FIG. 5 and FIG. 6, the foot member 143 may be provided as a pair so as to be connected to the first leg 141 and the second leg 142 respectively which are respectively connected to both sides of the robot body 110, and the pair of the foot members 143 may be connected to one another by a pair of connecting rods 148.

[43] At this time, as shown in FIG. 7 and FIG. 9, the foot member 143 includes a jump surface 149 which performs function of contacting and pushing the ground for jump.

[44] A spring 150 elastically connects the robot body 110 and the link mechanism 140.

For example, as shown in FIG. 9, one end of the spring 150 is connected to the robot body 110 and the other end thereof is connected to the first leg 141 of the link mechanism 140, so that the link mechanism 140 can be elastically connected to the robot body 110. The spring 150 can be connected to a frontal part of the first leg 141 which is in front of a first pivot point 144. At this time, the spring 150 is connected to the first leg 141 so as to be extended in response to pivot rotation of the first leg 141 toward the robot body 110.

[45] Meanwhile, a mobile robot according to an embodiment of the present invention includes a link structure control unit 160 which controls operation of the link mechanism 140. The link structure control unit 160 operates to apply force for making the link mechanism 140 overcome elastic force of the spring 150 to pivotally rotate toward the robot body 110 to the link mechanism 140 and then to remove the force applied to the link mechanism 140 such that the link mechanism 140 returns to its original state by elastic force of the spring 150. Hereinafter, operation of the link structure control unit 160 will be explained in more detail.

[46] The link structure control unit 160 includes a motor 161 which is mounted to the robot body 110.

[47] A first gear 162 is connected to the motor 161 so as to be rotated by the motor 161.

As shown in FIG. 7 and FIG. 8, the first gear 162 includes a part where gear teeth 163 are formed and a part where gear teeth are not formed. That is, a portion of outer surface of the first gear 162 is provided with the gear teeth 163, and the other portion thereof is not provided with gear teeth.

[48] A second gear 164 is rotatably mounted to the robot body 110. At this time, the second gear 164 is mounted to the robot body 110 in a state of being engaged with the first gear 162 such that the second gear 164 is engaged with the gear teeth 163 of the first gear 162 so as to be rotated by the first gear 162 and is freely rotatable in case of being exposed to the part of the first gear 162 where gear teeth are not formed. That is, referring to FIG. 10, the second gear 164 is rotated by the first gear 162 which is rotated by the motor 161 in case of being engaged with the part of the first gear 162 where gear teeth are formed, and is freely rotatable by being released from the engagement with the first gear 162 in case of being exposed to the part of the first gear 162 where gear teeth are not formed after being rotated by the first gear 162.

[49] A wire reel 165 which is connected to the second gear 164 to rotate with the second gear 164 is provided. For example, the second gear 164 and the wire reel 165 can be configured to be rotatable together with respect to the robot body 110 by being coupled to a rotating shaft 166 which is rotatably connected to the robot body 110.

[50] A wire 167 connecting the wire reel 165 and the link mechanism 140 is provided. For example, one end of the wire 167 may be connected to the wire reel 165 and the other end thereof may be connected to the link mechanism 140, and at this time, the wire 167 can be connected to the link mechanism 140 by being fixed to a connecting member 168 which is fixed to a connecting rod 148 of the link mechanism 140.

[51] In case the wire reel 165 rotates in a counter clockwise in FIG. 7, the wire 167 is wound to the wire reel 165, and accordingly, the link mechanism 140 overcomes elastic force of the spring 150 to pivotally rotate toward the robot body 110. If the first gear 162 further rotates in a state that the wire 167 is wound to the wire reel 165 so that the second gear 164 is exposed to the part of the first gear 162 where gear teeth are not formed, the second gear 164 and the wire reel 165 becomes free rotation state, and at this time the wire 167 is unwound from the wire reel 165 by elastic force of the spring 150, so the link mechanism 140 pivotally rotates in a direction of being apart from the robot body 110.

[52] Meanwhile, a mobile robot according to an embodiment of the present invention includes a ratchet 171 and a ratchet hook 173 for preventing reverse rotation of the first gear 162 thereby preventing overload of the motor 161. Here, the reverse rotation of the first gear 162 indicates that the first gear 162 rotates in a direction in which the wire 167 is unwound.

[53] The ratchet 171 is fixedly connected to the first gear 162 so as to rotate together with the first gear 162, and the ratchet hook 173 restricts the ratchet 171 to rotate in only one direction. For example, the ratchet 171 is provided with gear teeth inclined in one direction and the ratchet hook 173 is provided with a projection which is engaged with the gear teeth of the ratchet 171, and the ratchet hook 173 is elastically supported toward the gear teeth of the ratchet 171, so the ratchet hook 173 can allow the ratchet 171 to rotate in only one direction and prevent the ratchet 171 from rotate in the other direction. At this time, the ratchet hook 173 allows the ratchet 171 to rotate the first gear 162 in a direction in which the wire 167 is wound (i.e., in a direction of clockwise in FIG. 7) and prevents the ratchet 171 from rotating in an opposite direction.

[54] Meanwhile, a mobile robot according to an embodiment of the present invention may include a jump direction regulating pin 175 which regulates rotation position of the robot body 110 in a state that the robot body 110 rotates rearward by the pivot rotation of the link mechanism 140. The jump direction regulating pin 175 is rotatably connected to the robot body 110 such that an outer end of thereof can be extruded to the outside of the robot body 110.

[55] For example, the jump direction regulating pin 175 is extruded toward an upper rearward direction in a state that the robot body 110 is in a normal position as shown in FIG. 1 and FIG. 9, and faces the ground surface in a state that the robot body 110 is rotated rearward for jump as shown in FIG. 12 and 13.

[56] Furthermore, as shown in FIG. 1, a servomotor 177 for driving the jump direction regulating pin 175 to rotate is provided.

[57] In a state that the robot body 110 rotates rearward for jump as shown in FIG. 12, the rotation position of the robot body 110 can be regulated by regulating rotation of the jump direction regulating pin 175, and thereby jump direction of the mobile robot can be varied.

[58] Meanwhile, a mobile robot according to an embodiment of the present invention may further include an anti-fall-down bar 179 which is configured to be extruded toward the front of the robot body as so to limit forward rotation of the robot body 110.

[59] For example, the anti-fall-down bar 179 may have a shape of and is extruded to the front of the robot body 110 as shown in the drawings. When the robot body 110 rolls forward, the anti-fall-down bar 179 contacts the ground surface to prevent the robot body 110 from further rolling forward. The anti-fall-down bar 179 can prevent from rolling forward when a mobile robot fall down and quickly get a stable posture.

[60] Meanwhile, a mobile robot according to an embodiment of the present invention may be provided with a sensor for detecting height of an obstacle ahead. As shown in FIG. 1, an ultrasonic wave sensor 181 and a PSD (Positive Sensitive Detector) sensor 183 are provided at the front of the robot body 110 of the mobile robot.

[61] The ultrasonic wave sensor 181 detects distance to an obstacle ahead and generates a corresponding signal. At this time, the ultrasonic wave sensor 181 may be mounted such that sensing direction is horizontal to detect distance to an obstacle ahead. For example, as shown in FIG. 1 to FIG. 3, a pair of ultrasonic sensors 181 may be disposed in a lateral direction at the front of the robot body 110.

[62] The PSD sensor 183 is mounted to the front of the robot body 110 and is arranged so as to sense toward an upper direction upward by a predetermined angle from a horizontal direction. The PSD sensor 183 detects distance to an upper edge of an obstacle ahead thereof and generates a corresponding signal.

[63] A controller (not shown) which calculates height of an obstacle on the basis of the signals of the ultrasonic wave sensor 181 and the PSD sensor 183 may be provided. For example, using distance to an obstacle ahead according to the signal of the ultrasonic wave sensor 181 and height of the obstacle according to the signal of the PSD sensor 183, height of the obstacle can be calculated from the trigonometrical function. Meanwhile, the controller may control operations of the driving motor 130, the motor 161, and the servo motor 177. For example, the controller may include a microprocessor, a memory, and related hardware and software, and is formed to communicate with the above-mentioned sensors and to control the above-mentioned motors as will be appreciated by one of ordinary skill in the art. For example, the microprocessor may be activated by a predetermined program which is programmed to perform various functions such as moving, avoiding obstacles, jumping based on signals of various sensors, and various data for the same are stored in the memory.

[64] Meanwhile, the mobile robot according to an embodiment of the present invention may further include a first photo sensor 185 and a second photo sensor 187 which are mounted at a front side of the robot body 110. The controller receives signals of the first photo sensor 185 and the second photo sensor 187 and outputs corresponding control signals on the basis of the signals.

[65] The first photo sensor 185 detects whether a front region apart by a predetermined distance is an empty space and generates a corresponding signal. And the second photo sensor 187 detects whether a front region farther than the first region detected by the first photo sensor 185 is an empty space and generates a corresponding signal. At this time, the empty space means a space such as a space beyond steps where the mobile robot should perform falling operation.

[66] For example, as shown in FIG. 3, the first photo sensor 185 may be provided as a pair and are disposed on both sides of the front of the robot body 110, and the second photo sensor 187 may be mounted to the front of the robot body 110 so as to detect a region farther than the first photo sensor 185.

[67] At this time, the controller controls the driving motor 130 such that rotation speed of the wheels 120 is decreased in case that the signal received from the second photo sensor indicates that the detected region is an empty space, and controls the driving motor 130 such that the wheels 120 are arranged in a line in case that the signal received from the first photo sensor indicates that the detected region is an empty space. That is, in case that falling is needed at a region such as an end of steps, moving speed is decreased if an empty space is detected by the second photo sensor 187 which detects farther region, moving slowly, and then arranging the wheels 120 if an empty space is detected by the first photo sensor 185 which detected nearer region to prepare falling operation. Accordingly, falling can be effectively performed.

[68] The mobile robot according to an embodiment of the present invention may further include a camera 191 for photographing a front region. For example, as shown in FIG. 1 to FIG. 3, the camera 191 may be mounted at a front side of the robot body 110.

[69] Hereinafter, referring to FIG. 9 to FIG. 13, operation of the mobile robot according to an embodiment of the present invention will be explained.

[70] First, FIG. 9 shows the state of a case of maintaining normal posture such as normally moving or being stopped. In this case, the link mechanism 140 extrudes rearward from the robot body 110, and the foot member 143 contacts ground so that the mobile robot maintains stable posture.

[71] In case that jump is needed, as shown in FIG. 10, the wire 167 is wound around the wire reel 165 so as to pull the link mechanism 140 toward the robot body 110. In order that the wire 167 is wound around the wire reel 165, as described above, the motor 161 operates and accordingly the first gear 162 and the second gear 164 sequentially operate, so the wire 167 can be wound the wire reel 165. For example, the first gear 162 rotates clockwise in FIG. 7, and the second gear 164 which is engaged therewith rotates counter clockwise, and accordingly the wire reel 165 rotates counter clockwise so that the wire 167 is wound. If the wire 167 pulls the link mechanism 140, the first leg 141 and the second leg 142 pivotally rotate counter clockwise about the first pivot point 144 and the second pivot point 145 respectively, and accordingly the spring 150 gradually extends. At this time, the foot member 143 which is pivotally connected to the first leg 141 and the second leg 142 gradually rotates clockwise. In addition, as the link mechanism 140 gradually approaches to the robot body 110, the robot body 110 rotates rearward, that is, rotates counter clockwise in the drawing, by weight of the link mechanism 140.

[72] If the wire 167 is further wound at the state of FIG. 10, it becomes the states of FIG.

11 and FIG. 12. As shown in FIG. 12, if the wire 167 is fully wound, the spring 150 is further extended and a jump surface 149 of the foot member 143 of the link mechanism 140 contacts ground so that preparation for jump is completed. At this time, as shown in FIG. 13, the second gear 164 is engaged with the last end portion of the gear teeth 163 of the first gear 162, and if the first gear 162 further rotates from this state, the second gear 164 is exposed to the portion of the first gear 162 where gear teeth are not formed, so the second gear 164 and the wire reel 165 become free rotation state. Accordingly, the first leg 141 of the link mechanism 140 rotates in a clockwise (in FIG. 12 and FIG. 13) about the first pivot point 144 by elastic force of the spring 150, and accordingly the foot member 143 and the second leg 142 rotate together, and during this process the foot member 143 pushes ground and the mobile robot jumps with the repulsive power.

[73] Meanwhile, in the states of FIG. 12 and FIG. 13, rotation position of the jump direction regulating pin 175 can be regulated by driving the servo motor 177, so rotation position of the robot body 110 can be changed, and if the rotation position of the robot body 110 is changed, direction of force while the link mechanism 140 rotates is also changed so that jump direction of the mobile robot can be changed. Jump direction of the mobile robot can be controlled in this way.

[74] While this invention has been described in connection with what is presently considered to be the most practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

[75]

Industrial Applicability

[76] The present invention is applicable to a mobile robot having jump function.

[77]

[78]